From 08cbf3b50bfe713044f36b363c73768cd042f13c Mon Sep 17 00:00:00 2001 From: marha Date: Mon, 16 May 2011 08:06:12 +0000 Subject: xserver xkeyboar-config mesa git update 16 May 2011 --- xorg-server/hw/xfree86/doc/ddxDesign.xml | 9394 ++++++++++++++++++++++++++++++ 1 file changed, 9394 insertions(+) create mode 100644 xorg-server/hw/xfree86/doc/ddxDesign.xml (limited to 'xorg-server/hw/xfree86/doc/ddxDesign.xml') diff --git a/xorg-server/hw/xfree86/doc/ddxDesign.xml b/xorg-server/hw/xfree86/doc/ddxDesign.xml new file mode 100644 index 000000000..02909602c --- /dev/null +++ b/xorg-server/hw/xfree86/doc/ddxDesign.xml @@ -0,0 +1,9394 @@ + + %defs; + + + Device"> + Monitor"> + Display"> + InputDevice"> + Screen"> + ServerLayout"> + Driver"> + Module"> + Identifier"> + ServerFlags"> +] > + +
+ + + XFree86 DDX Design (Xorg server version &xserver.version;) + + + + The XFree86 Project, Inc. + + The X.Org Foundation, Inc. + + + JimGettys + Updates for X11R6.7 + + + + &xserver.reldate; + Xorg server version &xserver.version; + + + + +This document describes software undergoing continual evolution, and +the interfaces described here are subject to change without notice. +This document is intended to cover the interfaces as found in the +xorg-server-&xserver.version; release, but is probably not completely +in sync with the code base. + + + + + Preface + + +This document was originally the design spec for the DDX layer of the +XFree86 4.0 X server. The X.Org Foundation adopted the XFree86 4.4rc2 +version of that server as the basis of the Xorg server project, and has +evolved the XFree86 DDX layer greatly since forking. This document thus +covers only the current implementation of the XFree86 DDX as found in the +Xorg server &xserver.version; release, and no longer matches the XFree86 +server itself. + + + +The XFree86 Project's broad design principles for XFree86 4.0 were: + + keep it reasonable + + We cannot rewrite the complete server + + We don't want to re-invent the wheel + + + keep it modular + + As many things as possible should go into modules + + The basic loader binary should be minimal + + A clean design with well defined layering is + important + DDX specific global variables are a nono + + The structure should be flexible enough to allow + future extensions + The structure should minimize duplication of + common code + + keep important features in mind + + multiple screens, including multiple instances + of drivers + mixing different color depths and visuals on + different and ideally even on the same screen + + better control of the PCI device used + + better config file parser + get rid of all VGA compatibility assumptions + + + + + + +While the XFree86 project had a goal of avoiding changes to the DIX +layer unless they found major deficiencies there, to avoid divergence from +the X.Org sample implementation they were integrating changes from, the +X.Org developers now maintain both sides, and make changes where they are +most appropriate. This document concentrates on the XFree86 DDX layer used +in the Xorg server itself (the code found in hw/xfree86 +in the source tree), and developers will also want to refer to the +Xserver-spec documentation that covers the DIX layer +routines common to all the X servers in the sample implementation. + + + + + The xorg.conf File + + +The xorg.conf file format is based on the XF86Config format from XFree86 4.4, +which is in turn similar to the old XFree86 3.x XF86Config format, with the +following changes: + + + + &k.device; section + + + The &k.device; sections are similar to what they used to be, and + describe hardware-specific information for a single video card. + &k.device; + Some new keywords are added: + + + + Driver "drivername" + + Specifies the name of the driver to be used for the card. This + is mandatory. + + BusID "busslot" + + Specifies uniquely the location of the card on the bus. The + purpose is to identify particular cards in a multi-headed + configuration. The format of the argument is intentionally + vague, and may be architecture dependent. For a PCI bus, it + is something like "bus:slot:func". + + + + + + A &k.device; section is considered active if there is a reference + to it in an active &k.screen; section. + + + + + &k.screen; section + + + The &k.screen; sections are similar to what they used to be. They + no longer have a &k.driver; keyword, but an &k.identifier; keyword + is added. (The &k.driver; keyword may be accepted in place of the + &k.identifier; keyword for compatibility purposes.) The identifier + can be used to identify which screen is to be active when multiple + &k.screen; sections are present. It is possible to specify the active + screen from the command line. A default is chosen in the absence + of one being specified. A &k.screen; section is considered active + if there is a reference to it either from the command line, or from + an active &k.serverlayout; section. + + + + + &k.inputdevice; section + + + The &k.inputdevice; section is a new section that describes + configuration information for input devices. It replaces the old + Keyboard, Pointer and XInput + sections. Like the &k.device; section, it has two mandatory keywords: + &k.identifier; and &k.driver;. For compatibility purposes the old + Keyboard and Pointer sections are + converted by the parser into &k.inputdevice; sections as follows: + + + Keyboard + + &k.identifier; "Implicit Core Keyboard" + &k.driver; "keyboard" + + Pointer + + &k.identifier; "Implicit Core Pointer" + &k.driver; "mouse" + + + + + + An &k.inputdevice; section is considered active if there is a + reference to it in an active &k.serverlayout; section. An + &k.inputdevice; section may also be referenced implicitly if there + is no &k.serverlayout; section, if the command + line options is used, or if the &k.serverlayout; section doesn't + reference any &k.inputdevice; sections. In this case, the first + sections with drivers "keyboard" and "mouse" are used as the core + keyboard and pointer respectively. + + + + + &k.serverlayout; section + + + The &k.serverlayout; section is a new section that is used to identify + which &k.screen; sections are to be used in a multi-headed configuration, + and the relative layout of those screens. It also identifies which + &k.inputdevice; sections are to be used. Each &k.serverlayout; section + has an identifier, a list of &k.screen; section identifiers, and a list of + &k.inputdevice; section identifiers. &k.serverflags; options may also be + included in a &k.serverlayout; section, making it possible to override + the global values in the &k.serverflags; section. + + + + A &k.serverlayout; section can be made active by being referenced on + the command line. In the absence of this, a default will be chosen + (the first one found). The screen names may optionally be followed + by a number specifying the preferred screen number, and optionally + by information specifying the physical positioning of the screen, + either in absolute terms or relative to another screen (or screens). + When no screen number is specified, they are numbered according to + the order in which they are listed. The old (now obsolete) method + of providing the positioning information is to give the names of + the four adjacent screens. The order of these is top, bottom, left, + right. Here is an example of a &k.serverlayout; section for two + screens using the old method, with the second located to the right + of the first: + + + Section "ServerLayout" + Identifier "Main Layout" + Screen 0 "Screen 1" "" "" "" "Screen 2" + Screen 1 "Screen 2" + Screen "Screen 3" + EndSection + + + + + The preferred way of specifying the layout is to explicitly specify + the screen's location in absolute terms or relative to another + screen. + + + + In the absolute case, the upper left corner's coordinates are given + after the Absolute keyword. If the coordinates are + omitted, a value of (0,0) is assumed. An example + of absolute positioning follows: + + + Section "ServerLayout" + Identifier "Main Layout" + Screen 0 "Screen 1" Absolute 0 0 + Screen 1 "Screen 2" Absolute 1024 0 + Screen "Screen 3" Absolute 2048 0 + EndSection + + + + + In the relative case, the position is specified by either using one of + the following keywords followed by the name of the reference screen: + + + RightOf + LeftOf + Above + Below + Relative + + + + + When the Relative keyword is used, the reference screen + name is followed by the coordinates of the new screen's origin + relative to reference screen. The following example shows how to use + some of the relative positioning options. + + + Section "ServerLayout" + Identifier "Main Layout" + Screen 0 "Screen 1" + Screen 1 "Screen 2" RightOf "Screen 1" + Screen "Screen 3" Relative "Screen 1" 2048 0 + EndSection + + + + + + Options + + + Options are used more extensively. They may appear in most sections + now. Options related to drivers can be present in the &k.screen;, + &k.device; and &k.monitor; sections and the &k.display; subsections. + The order of precedence is &k.display;, &k.screen;, &k.monitor;, + &k.device;. Options have been extended to allow an optional value + to be specified in addition to the option name. For more details + about options, see the Options section + for details. + + + + + + Driver Interface + + +The driver interface consists of a minimal set of entry points that are +required based on the external events that the driver must react to. +No non-essential structure is imposed on the way they are used beyond +that. This is a significant difference compared with the old design. + + + +The entry points for drawing operations are already taken care of by +the framebuffer code (including, XAA). Extensions and enhancements to +framebuffer code are outside the scope of this document. + + + +This approach to the driver interface provides good flexibility, but does +increase the complexity of drivers. To help address this, the XFree86 +common layer provides a set of helper functions to take care of things +that most drivers need. These helpers help minimise the amount of code +duplication between drivers. The use of helper functions by drivers is +however optional, though encouraged. The basic philosophy behind the +helper functions is that they should be useful to many drivers, that +they should balance this against the complexity of their interface. It +is inevitable that some drivers may find some helpers unsuitable and +need to provide their own code. + + + +Events that a driver needs to react to are: + + + ScreenInit + + + An initialisation function is called from the DIX layer for each + screen at the start of each server generation. + + + Enter VT + + + The server takes control of the console. + + + Leave VT + + + The server releases control of the console. + + + Mode Switch + + + Change video mode. + + + ViewPort change + + + Change the origin of the physical view port. + + + ScreenSaver state change + + + Screen saver activation/deactivation. + + + CloseScreen + + + A close screen function is called from the DIX layer for each screen + at the end of each server generation. + + + + + + +In addition to these events, the following functions are required by +the XFree86 common layer: + + + Identify + + + Print a driver identifying message. + + + Probe + + + This is how a driver identifies if there is any hardware present that + it knows how to drive. + + + PreInit + + + Process information from the xorg.conf file, determine the + full characteristics of the hardware, and determine if a valid + configuration is present. + + + + + +The VidMode extension also requires: + + + ValidMode + + + Identify if a new mode is usable with the current configuration. + The PreInit function (and/or helpers it calls) may also make use + of the ValidMode function or something similar. + + + + + + +Other extensions may require other entry points. The drivers will +inform the common layer of these in such cases. + + + + + Resource Access Control Introduction + + +Graphics devices are accessed through ranges in I/O or memory space. +While most modern graphics devices allow relocation of such ranges many +of them still require the use of well established interfaces such as +VGA memory and IO ranges or 8514/A IO ranges. With modern buses (like +PCI) it is possible for multiple video devices to share access to these +resources. The RAC (Resource Access Control) subsystem provides a +mechanism for this. + + + + Terms and Definitions + + + Bus + + + Bus is ambiguous as it is used for different things: it may refer + to physical incompatible extension connectors in a computer system. + The RAC system knows two such systems: The ISA bus and the PCI bus. + (On the software level EISA, MCA and VL buses are currently treated + like ISA buses). Bus may also refer to logically different + entities on a single bus system which are connected via bridges. A + PCI system may have several distinct PCI buses connecting each other + by PCI-PCI bridges or to the host CPU by HOST-PCI bridges. + + + + Systems that host more than one bus system link these together using + bridges. Bridges are a concern to RAC as they might block or pass + specific resources. PCI-PCI bridges may be set up to pass VGA + resources to the secondary bus. PCI-ISA buses pass any resources not + decoded on the primary PCI bus to the ISA bus. This way VGA resources + (although exclusive on the ISA bus) can be shared by ISA and PCI + cards. Currently HOST-PCI bridges are not yet handled by RAC as they + require specific drivers. + + + + + Entity + + + The smallest independently addressable unit on a system bus is + referred to as an entity. So far we know ISA and PCI entities. PCI + entities can be located on the PCI bus by an unique ID consisting of + the bus, card and function number. + + + + + Resource + + + Resource refers to a range of memory or I/O addresses an entity + can decode. + + + + If a device is capable of disabling this decoding the resource is + called sharable. For PCI devices a generic method is provided to + control resource decoding. Other devices will have to provide a + device specific function to control decoding. + + + + If the entity is capable of decoding this range at a different + location this resource is considered relocatable. + + + + Resources which start at a specific address and occupy a single + continuous range are called block resources. + + + + Alternatively resource addresses can be decoded in a way that they + satisfy the conditions: + + address & mask == base + + and + + base & mask == base + + Resources addressed in such a way are called sparse resources. + + + + + + Server States + + + The resource access control system knows two server states: the + SETUP and the OPERATING state. The SETUP state is entered whenever + a mode change takes place or the server exits or does VT switching. + During this state all entity resources are under resource access + control. During OPERATING state only those entities are controlled + which actually have shared resources that conflict with others. + + + + + + + Control Flow in the Server and Mandatory Driver Functions + + +At the start of each server generation, main() +(dix/main.c) calls the DDX function +InitOutput(). This is the first place that the DDX gets +control. InitOutput() is expected to fill in the global +screenInfo struct, and one +screenInfo.screen[] entry for each screen present. +Here is what InitOutput() does: + + + + Parse the xorg.conf file + + + This is done at the start of the first server generation only. + + + + The xorg.conf file is read in full, and the resulting information + stored in data structures. None of the parsed information is + processed at this point. The parser data structures are opaque to + the video drivers and to most of the common layer code. + + + + The entire file is parsed first to remove any section ordering + requirements. + + + + + + Initial processing of parsed information and command line options + + + + This is done at the start of the first server generation only. + + + + The initial processing is to determine paths like the + ModulePath, etc, and to determine which &k.serverlayout;, + &k.screen; and &k.device; sections are active. + + + + + + Enable port I/O access + + + Port I/O access is controlled from the XFree86 common layer, and is + all or nothing. It is enabled prior to calling driver probes, at + the start of subsequent server generations, and when VT switching + back to the Xserver. It is disabled at the end of server generations, + and when VT switching away from the Xserver. + + + + The implementation details of this may vary on different platforms. + + + + + + General bus probe + + + This is done at the start of the first server generation only. + + + + In the case of ix86 machines, this will be a general PCI probe. + The full information obtained here will be available to the drivers. + This information persists for the life of the Xserver. In the PCI + case, the PCI information for all video cards found is available by + calling xf86GetPciVideoInfo(). + + +
+ + pciVideoPtr *xf86GetPciVideoInfo(void); + +
+ returns a pointer to a list of pointers to + pciVideoRec entries, of which there is one for + each detected PCI video card. The list is terminated with a + NULL pointer. If no PCI video cards were + detected, the return value is NULL. + +
+
+ + + After the bus probe, the resource broker is initialised. + + + + + + Load initial set of modules + + + This is done at the start of the first server generation only. + + + + The core server contains a list of mandatory modules. These are loaded + first. Currently the only module on this list is the bitmap font module. + + + + The next set of modules loaded are those specified explicitly in the + &k.module; section of the config file. + + + + The final set of initial modules are the driver modules referenced + by the active &k.device; and &k.inputdevice; sections in the config + file. Each of these modules is loaded exactly once. + + + + + + Register Video and Input Drivers + + + This is done at the start of the first server generation only. + + + + When a driver module is loaded, the loader calls its + Setup function. For video drivers, this function + calls xf86AddDriver() to register the driver's + DriverRec, which contains a small set of essential + details and driver entry points required during the early phase of + InitOutput(). xf86AddDriver() + adds it to the global xf86DriverList[] array. + + + + The DriverRec contains the driver canonical name, + the Identify(), + Probe() and AvailableOptions() + function entry points as well as a pointer + to the driver's module (as returned from the loader when the driver + was loaded) and a reference count which keeps track of how many + screens are using the driver. The entry driver entry points are + those required prior to the driver allocating and filling in its + ScrnInfoRec. + + + + For a static server, the xf86DriverList[] array is + initialised at build time, and the loading of modules is not done. + + + + A similar procedure is used for input drivers. The input driver's + Setup function calls + xf86AddInputDriver() to register the driver's + InputDriverRec, which contains a small set of + essential details and driver entry points required during the early + phase of InitInput(). + xf86AddInputDriver() adds it to the global + xf86InputDriverList[] array. For a static server, + the xf86InputDriverList[] array is initialised at + build time. + + + + Both the xf86DriverList[] and + xf86InputDriverList[] arrays have been initialised + by the end of this stage. + + + + Once all the drivers are registered, their + ChipIdentify() functions are called. + + +
+ + void ChipIdentify(int flags); + +
+ This is expected to print a message indicating the driver name, + a short summary of what it supports, and a list of the chipset + names that it supports. It may use the xf86PrintChipsets() helper + to do this. +
+
+ +
+ + void xf86PrintChipsets(const char *drvname, const char *drvmsg, + SymTabPtr chips); + +
+ This function provides an easy way for a driver's ChipIdentify + function to format the identification message. +
+
+ + + + Initialise Access Control + + + This is done at the start of the first server generation only. + + + + The Resource Access Control (RAC) subsystem is initialised before + calling any driver functions that may access hardware. All generic + bus information is probed and saved (for restoration later). All + (shared resource) video devices are disabled at the generic bus + level, and a probe is done to find the primary video device. These + devices remain disabled for the next step. + + + + + + Video Driver Probe + + + This is done at the start of the first server generation only. The + ChipProbe() function of each registered video driver + is called. + + +
+ + Bool ChipProbe(DriverPtr drv, int flags); + +
+ The purpose of this is to identify all instances of hardware + supported by the driver. The flags value is currently either 0, + PROBE_DEFAULT or PROBE_DETECT. + PROBE_DETECT is used if "-configure" or "-probe" + command line arguments are given and indicates to the + Probe() function that it should not configure the + bus entities and that no xorg.conf information is available. + + + + The probe must find the active device sections that match the + driver by calling xf86MatchDevice(). The number + of matches found limits the maximum number of instances for this + driver. If no matches are found, the function should return + FALSE immediately. + + + + Devices that cannot be identified by using device-independent + methods should be probed at this stage (keeping in mind that access + to all resources that can be disabled in a device-independent way + are disabled during this phase). The probe must be a minimal + probe. It should just determine if there is a card present that + the driver can drive. It should use the least intrusive probe + methods possible. It must not do anything that is not essential, + like probing for other details such as the amount of memory + installed, etc. It is recommended that the + xf86MatchPciInstances() helper function be used + for identifying matching PCI devices, and similarly the + xf86MatchIsaInstances() for ISA (non-PCI) devices + (see the RAC section). These helpers also + checks and claims the appropriate entity. When not using the + helper, that should be done with xf86CheckPciSlot() + and xf86ClaimPciSlot() for PCI devices and + xf86ClaimIsaSlot() for ISA devices (see the + RAC section). + + + + The probe must register all non-relocatable resources at this + stage. If a resource conflict is found between exclusive resources + the driver will fail immediately. This is usually best done with + the xf86ConfigPciEntity() helper function + for PCI and xf86ConfigIsaEntity() for ISA + (see the RAC section). It is possible to + register some entity specific functions with those helpers. When + not using the helpers, the xf86AddEntityToScreen() + xf86ClaimFixedResources() and + xf86SetEntityFuncs() should be used instead (see + the RAC section). + + + + If a chipset is specified in an active device section which the + driver considers relevant (ie it has no driver specified, or the + driver specified matches the driver doing the probe), the Probe + must return FALSE if the chipset doesn't match + one supported by the driver. + + + + If there are no active device sections that the driver considers + relevant, it must return FALSE. + + + + Allocate a ScrnInfoRec for each active instance of the + hardware found, and fill in the basic information, including the + other driver entry points. This is best done with the + xf86ConfigIsaEntity() helper function for ISA + instances or xf86ConfigPciEntity() for PCI instances. + These functions allocate a ScrnInfoRec for active + entities. Optionally xf86AllocateScreen() + function may also be used to allocate the ScrnInfoRec. + Any of these functions take care of initialising fields to defined + unused values. + + + + Claim the entities for each instance of the hardware found. This + prevents other drivers from claiming the same hardware. + + + + Must leave hardware in the same state it found it in, and must not + do any hardware initialisation. + + + + All detection can be overridden via the config file, and that + parsed information is available to the driver at this stage. + + + + Returns TRUE if one or more instances are found, + and FALSE otherwise. + + +
+ +
+ + int xf86MatchDevice(const char *drivername, + GDevPtr **driversectlist) + +
+ This function takes the name of the driver and returns via + driversectlist a list of device sections that + match the driver name. The function return value is the number + of matches found. If a fatal error is encountered the return + value is -1. + + + + The caller should use xfree() to free + *driversectlist when it is no longer needed. + + +
+ +
+ + ScrnInfoPtr xf86AllocateScreen(DriverPtr drv, int flags) + +
+ This function allocates a new ScrnInfoRec in the + xf86Screens[] array. This function is normally + called by the video driver ChipProbe() functions. + The return value is a pointer to the newly allocated + ScrnInfoRec. The scrnIndex, + origIndex, module and + drv fields are initialised. The reference count + in drv is incremented. The storage for any + currently allocated privates pointers is also allocated and + the privates field initialised (the privates data + is of course not allocated or initialised). This function never + returns on failure. If the allocation fails, the server exits + with a fatal error. The flags value is not currently used, and + should be set to zero. +
+
+ + + At the completion of this, a list of ScrnInfoRecs + have been allocated in the xf86Screens[] array, and + the associated entities and fixed resources have been claimed. The + following ScrnInfoRec fields must be initialised at + this point: + + + driverVersion + driverName + scrnIndex(*) + origIndex(*) + drv(*) + module(*) + name + Probe + PreInit + ScreenInit + EnterVT + LeaveVT + numEntities + entityList + access + + + (*) These are initialised when the ScrnInfoRec + is allocated, and not explicitly by the driver. + + + + The following ScrnInfoRec fields must be initialised + if the driver is going to use them: + + + SwitchMode + AdjustFrame + FreeScreen + ValidMode + + + + + + Matching Screens + + + This is done at the start of the first server generation only. + + + + After the Probe phase is finished, there will be some number of + ScrnInfoRecs. These are then matched with the active + &k.screen; sections in the xorg.conf, and those not having an active + &k.screen; section are deleted. If the number of remaining screens + is 0, InitOutput() sets + screenInfo.numScreens to 0 and + returns. + + + + At this point the following fields of the ScrnInfoRecs + must be initialised: + + + confScreen + + + + + + + Allocate non-conflicting resources + + + This is done at the start of the first server generation only. + + + + Before calling the drivers again, the resource information collected + from the Probe phase is processed. This includes checking the extent + of PCI resources for the probed devices, and resolving any conflicts + in the relocatable PCI resources. It also reports conflicts, checks + bus routing issues, and anything else that is needed to enable the + entities for the next phase. + + + + If any drivers registered an EntityInit() function + during the Probe phase, then they are called here. + + + + + + Sort the Screens and pre-check Monitor Information + + + This is done at the start of the first server generation only. + + + + The list of screens is sorted to match the ordering requested in the + config file. + + + + The list of modes for each active monitor is checked against the + monitor's parameters. Invalid modes are pruned. + + + + + + PreInit + + + This is done at the start of the first server generation only. + + + + For each ScrnInfoRec, enable access to the screens entities and call + the ChipPreInit() function. + + +
+ + Bool ChipPreInit(ScrnInfoRec screen, int flags); + +
+ The purpose of this function is to find out all the information + required to determine if the configuration is usable, and to + initialise those parts of the ScrnInfoRec that + can be set once at the beginning of the first server generation. + + + + The number of entities registered for the screen should be checked + against the expected number (most drivers expect only one). The + entity information for each of them should be retrieved (with + xf86GetEntityInfo()) and checked for the correct + bus type and that none of the sharable resources registered during + the Probe phase was rejected. + + + + Access to resources for the entities that can be controlled in a + device-independent way are enabled before this function is called. + If the driver needs to access any resources that it has disabled + in an EntityInit() function that it registered, + then it may enable them here providing that it disables them before + this function returns. + + + + This includes probing for video memory, clocks, ramdac, and all + other HW info that is needed. It includes determining the + depth/bpp/visual and related info. It includes validating and + determining the set of video modes that will be used (and anything + that is required to determine that). + + + + This information should be determined in the least intrusive way + possible. The state of the HW must remain unchanged by this + function. Although video memory (including MMIO) may be mapped + within this function, it must be unmapped before returning. Driver + specific information should be stored in a structure hooked into + the ScrnInfoRec's driverPrivate + field. Any other modules which require persistent data (ie data + that persists across server generations) should be initialised in + this function, and they should allocate a privates index to + hook their data into by calling + xf86AllocateScrnInfoPrivateIndex(). The privates + data is persistent. + + + + Helper functions for some of these things are provided at the + XFree86 common level, and the driver can choose to make use of + them. + + + + All additional resources that the screen needs must be registered + here. This should be done with + xf86RegisterResources(). If some of the fixed + resources registered in the Probe phase are not needed or not + decoded by the hardware when in the OPERATING server state, their + status should be updated with + xf86SetOperatingState(). + + + + Modules may be loaded at any point in this function, and all + modules that the driver will need must be loaded before the end + of this function. Either the xf86LoadSubModule() + or the xf86LoadDrvSubModule() function should be + used to load modules depending on whether a + ScrnInfoRec has been set up. A driver may unload + a module within this function if it was only needed temporarily, + and the xf86UnloadSubModule() function should be used + to do that. Otherwise there is no need to explicitly unload modules + because the loader takes care of module dependencies and will + unload submodules automatically if/when the driver module is + unloaded. + + + + The bulk of the ScrnInfoRec fields should be filled + out in this function. + + + + ChipPreInit() returns FALSE when + the configuration is unusable in some way (unsupported depth, no + valid modes, not enough video memory, etc), and TRUE + if it is usable. + + + + It is expected that if the ChipPreInit() function + returns TRUE, then the only reasons that subsequent + stages in the driver might fail are lack or resources (like xalloc + failures). All other possible reasons for failure should be + determined by the ChipPreInit() function. +
+
+ + + The ScrnInfoRecs for screens where the ChipPreInit() fails are removed. + If none remain, InitOutput() sets screenInfo.numScreens to 0 and returns. + + + + At this point, further fields of the ScrnInfoRecs would normally be + filled in. Most are not strictly mandatory, but many are required + by other layers and/or helper functions that the driver may choose + to use. The documentation for those layers and helper functions + indicates which they require. + + + + The following fields of the ScrnInfoRecs should be filled in if the + driver is going to use them: + + + monitor + display + depth + pixmapBPP + bitsPerPixel + weight (>8bpp only) + mask (>8bpp only) + offset (>8bpp only) + rgbBits (8bpp only) + gamma + defaultVisual + maxHValue + maxVValue + virtualX + virtualY + displayWidth + frameX0 + frameY0 + frameX1 + frameY1 + zoomLocked + modePool + modes + currentMode + progClock (TRUE if clock is programmable) + chipset + ramdac + clockchip + numClocks (if not programmable) + clock[] (if not programmable) + videoRam + biosBase + memBase + memClk + driverPrivate + chipID + chipRev + + + +
+ + pointer xf86LoadSubModule(ScrnInfoPtr pScrn, const char *name); + and + pointer xf86LoadDrvSubModule(DriverPtr drv, const char *name); + +
+ Load a module that a driver depends on. This function loads the + module name as a sub module of the driver. The + return value is a handle identifying the new module. If the load + fails, the return value will be NULL. If a driver + needs to explicitly unload a module it has loaded in this way, + the return value must be saved and passed to + xf86UnloadSubModule() when unloading. + +
+
+ +
+ + void xf86UnloadSubModule(pointer module); + +
+ Unloads the module referenced by module. + module should be a pointer returned previously + by xf86LoadSubModule() or + xf86LoadDrvSubModule() . + +
+
+ + + + Cleaning up Unused Drivers + + + At this point it is known which screens will be in use, and which + drivers are being used. Unreferenced drivers (and modules they + may have loaded) are unloaded here. + + + + + + Consistency Checks + + + The parameters that must be global to the server, like pixmap formats, + bitmap bit order, bitmap scanline unit and image byte order are + compared for each of the screens. If a mismatch is found, the server + exits with an appropriate message. + + + + + + Check if Resource Control is Needed + + + Determine if resource access control is needed. This is the case + if more than one screen is used. If necessary the RAC wrapper module + is loaded. + + + + + AddScreen (ScreenInit) + + + At this point, the valid screens are known. + AddScreen() is called for each of them, passing + ChipScreenInit() as the argument. + AddScreen() is a DIX function that allocates a new + screenInfo.screen[] entry (aka + pScreen), and does some basic initialisation of it. + It then calls the ChipScreenInit() function, with + pScreen as one of its arguments. If + ChipScreenInit() returns FALSE, + AddScreen() returns -1. Otherwise + it returns the index of the screen. AddScreen() + should only fail because of programming errors or failure to allocate + resources (like memory). All configuration problems should be + detected BEFORE this point. + + +
+ + Bool ChipScreenInit(int index, ScreenPtr pScreen, + int argc, char **argv); + +
+ This is called at the start of each server generation. + + + + Fill in all of pScreen, possibly doing some of + this by calling ScreenInit functions from other layers like mi, + framebuffers (cfb, etc), and extensions. + + + + Decide which operations need to be placed under resource access + control. The classes of operations are the frame buffer operations + (RAC_FB), the pointer operations + (RAC_CURSOR), the viewport change operations + (RAC_VIEWPORT) and the colormap operations + (RAC_COLORMAP). Any operation that requires + resources which might be disabled during OPERATING state should + be set to use RAC. This can be specified separately for memory + and IO resources (the racMemFlags and + racIoFlags fields of the ScrnInfoRec + respectively). + + + + Map any video memory or other memory regions. + + + + Save the video card state. Enough state must be saved so that + the original state can later be restored. + + + + Initialise the initial video mode. The ScrnInfoRec's + vtSema field should be set to TRUE + just prior to changing the video hardware's state. + +
+
+ + + + The ChipScreenInit() function (or functions from other + layers that it calls) should allocate entries in the + ScreenRec's devPrivates area by + calling AllocateScreenPrivateIndex() if it needs + per-generation storage. Since the ScreenRec's + devPrivates information is cleared for each server + generation, this is the correct place to initialise it. + + + + After AddScreen() has successfully returned, the + following ScrnInfoRec fields are initialised: + + + pScreen + racMemFlags + racIoFlags + + + + + The ChipScreenInit() function should initialise the + CloseScreen and SaveScreen fields + of pScreen. The old value of + pScreen->CloseScreen should be saved as part of + the driver's per-screen private data, allowing it to be called from + ChipCloseScreen(). This means that the existing + CloseScreen() function is wrapped. + + + + + Finalising RAC Initialisation + + + After all the ChipScreenInit() functions have been + called, each screen has registered its RAC requirements. This + information is used to determine which shared resources are requested + by more than one driver and set the access functions accordingly. + This is done following these rules: + + + + The sharable resources registered by each entity are compared. + If a resource is registered by more than one entity the entity + will be marked to indicate that it needs to share this resources + type (IO or MEM). + + + + A resource marked disabled during OPERATING state will be + ignored entirely. + + + + A resource marked unused will only conflict with an overlapping + resource of an other entity if the second is actually in use + during OPERATING state. + + + + If an unused resource was found to conflict but the entity + does not use any other resource of this type the entire resource + type will be disabled for that entity. + + + + + + + + Finishing InitOutput() + + + At this point InitOutput() is finished, and all the + screens have been setup in their initial video mode. + + + + + + Mode Switching + + + When a SwitchMode event is received, ChipSwitchMode() + is called (when it exists): + + +
+ + Bool ChipSwitchMode(int index, DisplayModePtr mode, int flags); + +
+ Initialises the new mode for the screen identified by + index;. The viewport may need to be adjusted + also. + +
+
+ + + + + Changing Viewport + + + When a Change Viewport event is received, + ChipAdjustFrame() is called (when it exists): + + +
+ + void ChipAdjustFrame(int index, int x, int y, int flags); + +
+ Changes the viewport for the screen identified by + index;. + + + + It should be noted that many chipsets impose restrictions on where the + viewport may be placed in the virtual resolution, either for alignment + reasons, or to prevent the start of the viewport from being positioned + within a pixel (as can happen in a 24bpp mode). After calculating the + value the chipset's panning registers need to be set to for non-DGA + modes, this function should recalculate the ScrnInfoRec's + frameX0, frameY0, frameX1 + and frameY1 fields to correspond to that value. If + this is not done, switching to another mode might cause the position + of a hardware cursor to change. + +
+
+ + + + + VT Switching + + + When a VT switch event is received, xf86VTSwitch() + is called. xf86VTSwitch() does the following: + + + On ENTER: + + + + enable port I/O access + + + + save and initialise the bus/resource state + + + + enter the SETUP server state + + + + calls ChipEnterVT() for each screen + + + + enter the OPERATING server state + + + + validate GCs + + + + Restore fb from saved pixmap for each screen + + + + Enable all input devices + + + + + + On LEAVE: + + + + Save fb to pixmap for each screen + + + + validate GCs + + + + enter the SETUP server state + + + + calls ChipLeaveVT() for each screen + + + + disable all input devices + + + + restore bus/resource state + + + + disables port I/O access + + + + + + + +
+ + Bool ChipEnterVT(int index, int flags); + +
+ This function should initialise the current video mode and + initialise the viewport, turn on the HW cursor if appropriate, + etc. + + + + Should it re-save the video state before initialising the video + mode? + + +
+ +
+ + void ChipLeaveVT(int index, int flags); + +
+ This function should restore the saved video state. If + appropriate it should also turn off the HW cursor, and invalidate + any pixmap/font caches. + + +
+ + + Optionally, ChipLeaveVT() may also unmap memory + regions. If so, ChipEnterVT() will need to remap + them. Additionally, if an aperture used to access video memory is + unmapped and remapped in this fashion, ChipEnterVT() + will also need to notify the framebuffer layers of the aperture's new + location in virtual memory. This is done with a call to the screen's + ModifyPixmapHeader() function, as follows + + +
+ + (*pScreen->ModifyPixmapHeader)(pScrn->ppix, + -1, -1, -1, -1, -1, NewApertureAddress); + +
+ where the ppix field in a ScrnInfoRec + points to the pixmap used by the screen's + SaveRestoreImage() function to hold the screen's + contents while switched out. + + +
+ + + Other layers may wrap the ChipEnterVT() and + ChipLeaveVT() functions if they need to take some + action when these events are received. + + + + + End of server generation + + + At the end of each server generation, the DIX layer calls + ChipCloseScreen() for each screen: + + +
+ + Bool ChipCloseScreen(int index, ScreenPtr pScreen); + +
+ This function should restore the saved video state and unmap the + memory regions. + + + + It should also free per-screen data structures allocated by the + driver. Note that the persistent data held in the + ScrnInfoRec's driverPrivate field + should not be freed here because it is needed by subsequent server + generations. + + + + The ScrnInfoRec's vtSema field + should be set to FALSE once the video HW state + has been restored. + + + + Before freeing the per-screen driver data the saved + CloseScreen value should be restored to + pScreen->CloseScreen, and that function should + be called after freeing the data. + +
+
+ + + + + Optional Driver Functions + + +The functions outlined here can be called from the XFree86 common layer, +but their presence is optional. + + + + Mode Validation + + + When a mode validation helper supplied by the XFree86-common layer is + being used, it can be useful to provide a function to check for hw + specific mode constraints: + + +
+ + ModeStatus ChipValidMode(int index, DisplayModePtr mode, + Bool verbose, int flags); + +
+ Check the passed mode for hw-specific constraints, and return the + appropriate status value. + +
+
+ + +This function may also modify the effective timings and clock of the passed +mode. These have been stored in the mode's Crtc* and +SynthClock elements, and have already been adjusted for +interlacing, doublescanning, multiscanning and clock multipliers and dividers. +The function should not modify any other mode field, unless it wants to modify +the mode timings reported to the user by xf86PrintModes(). + + + +The function is called once for every mode in the xorg.conf Monitor section +assigned to the screen, with flags set to +MODECHECK_INITIAL. It is subsequently called for every mode +in the xorg.conf Display subsection assigned to the screen, with +flags set to MODECHECK_FINAL. In the second +case, the mode will have successfully passed all other tests. In addition, +the ScrnInfoRec's virtualX, +virtualY and displayWidth fields will have been +set as if the mode to be validated were to be the last mode accepted. + + + +In effect, calls with MODECHECK_INITIAL are intended for checks that do not +depend on any mode other than the one being validated, while calls with +MODECHECK_FINAL are intended for checks that may involve more than one mode. + + + + + Free screen data + + + When a screen is deleted prior to the completion of the ScreenInit + phase the ChipFreeScreen() function is called when defined. + + +
+ + void ChipFreeScreen(int scrnindex, int flags); + +
+ Free any driver-allocated data that may have been allocated up to + and including an unsuccessful ChipScreenInit() + call. This would predominantly be data allocated by + ChipPreInit() that persists across server + generations. It would include the driverPrivate, + and any privates entries that modules may have allocated. + +
+
+ + + + + + Recommended driver functions + + +The functions outlined here are for internal use by the driver only. +They are entirely optional, and are never accessed directly from higher +layers. The sample function declarations shown here are just examples. +The interface (if any) used is up to the driver. + + + + Save + + + Save the video state. This could be called from ChipScreenInit() and + (possibly) ChipEnterVT(). + + +
+ + void ChipSave(ScrnInfoPtr pScrn); + +
+ Saves the current state. This will only be saving pre-server + states or states before returning to the server. There is only + one current saved state per screen and it is stored in private + storage in the screen. + +
+
+ + + + Restore + + + Restore the original video state. This could be called from the + ChipLeaveVT() and ChipCloseScreen() + functions. + + +
+ + void ChipRestore(ScrnInfoPtr pScrn); + +
+ Restores the saved state from the private storage. Usually only + used for restoring text modes. + +
+
+ + + + + Initialise Mode + + + Initialise a video mode. This could be called from the + ChipScreenInit(), ChipSwitchMode() + and ChipEnterVT() functions. + + +
+ + Bool ChipModeInit(ScrnInfoPtr pScrn, DisplayModePtr mode); + +
+ Programs the hardware for the given video mode. + +
+
+ + + + + + Data and Data Structures + + + Command line data + + +Command line options are typically global, and are stored in global +variables. These variables are read-only and are available to drivers +via a function call interface. Most of these command line values are +processed via helper functions to ensure that they are treated consistently +by all drivers. The other means of access is provided for cases where +the supplied helper functions might not be appropriate. + + + +Some of them are: + + + xf86Verbose verbosity level + xf86Bpp -bpp from the command line + xf86Depth -depth from the command line + xf86Weight -weight from the command line + xf86Gamma -{r,g,b,}gamma from the command line + xf86FlipPixels -flippixels from the command line + xf86ProbeOnly -probeonly from the command line + defaultColorVisualClass -cc from the command line + + + + +If we ever do allow for screen-specific command line options, we may +need to rethink this. + + + +These can be accessed in a read-only manner by drivers with the following +functions: + + +
+ + int xf86GetVerbosity(); + +
+ Returns the value of xf86Verbose. +
+ +
+ +
+ + int xf86GetDepth(); + +
+ Returns the command line setting. If not + set on the command line, -1 is returned. +
+ +
+ +
+ + rgb xf86GetWeight(); + +
+ Returns the command line setting. If not + set on the command line, {0, 0, 0} is returned. +
+ +
+ +
+ + Gamma xf86GetGamma(); + +
+ Returns the or , + , command line settings. + If not set on the command line, {0.0, 0.0, 0.0} + is returned. +
+ +
+ +
+ + Bool xf86GetFlipPixels(); + +
+ Returns TRUE if is + present on the command line, and FALSE otherwise. +
+ +
+ +
+ + const char *xf86GetServerName(); + +
+ Returns the name of the X server from the command line. +
+ +
+ + + + Data handling + + +Config file data contains parts that are global, and parts that are +Screen specific. All of it is parsed into data structures that neither +the drivers or most other parts of the server need to know about. + + + +The global data is typically not required by drivers, and as such, most +of it is stored in the private xf86InfoRec. + + + +The screen-specific data collected from the config file is stored in +screen, device, display, monitor-specific data structures that are separate +from the ScrnInfoRecs, with the appropriate elements/fields +hooked into the ScrnInfoRecs as required. The screen +config data is held in confScreenRec, device data in +the GDevRec, monitor data in the MonRec, +and display data in the DispRec. + + + +The XFree86 common layer's screen specific data (the actual data in use +for each screen) is held in the ScrnInfoRecs. As has +been outlined above, the ScrnInfoRecs are allocated at probe +time, and it is the responsibility of the Drivers' Probe() +and PreInit() functions to finish filling them in based +on both data provided on the command line and data provided from the +Config file. The precedence for this is: + +
+ command line -> config file -> probed/default data +
+ + + +For most things in this category there are helper functions that the +drivers can use to ensure that the above precedence is consistently +used. + + + +As well as containing screen-specific data that the XFree86 common layer +(including essential parts of the server infrastructure as well as helper +functions) needs to access, it also contains some data that drivers use +internally. When considering whether to add a new field to the +ScrnInfoRec, consider the balance between the convenience +of things that lots of drivers need and the size/obscurity of the +ScrnInfoRec. + + + +Per-screen driver specific data that cannot be accommodated with the +static ScrnInfoRec fields is held in a driver-defined +data structure, a pointer to which is assigned to the +ScrnInfoRec's driverPrivate field. This +is per-screen data that persists across server generations (as does the +bulk of the static ScrnInfoRec data). It would typically +also include the video card's saved state. + + + +Per-screen data for other modules that the driver uses (for example, +the XAA module) that is reset for each server generation is hooked into +the ScrnInfoRec through it's privates +field. + + + +Once it has stabilised, the data structures and variables accessible to +video drivers will be documented here. In the meantime, those things +defined in the xf86.h and xf86str.h +files are visible to video drivers. Things defined in +xf86Priv.h and xf86Privstr.h are NOT +intended to be visible to video drivers, and it is an error for a driver +to include those files. + + + + + + Accessing global data + + +Some other global state information that the drivers may access via +functions is as follows: + + +
+ + Bool xf86ServerIsExiting(); + +
+ Returns TRUE if the server is at the end of a + generation and is in the process of exiting, and + FALSE otherwise. +
+ +
+ +
+ + Bool xf86ServerIsResetting(); + +
+ Returns TRUE if the server is at the end of a + generation and is in the process of resetting, and + FALSE otherwise. +
+ +
+ +
+ + Bool xf86ServerIsInitialising(); + +
+ Returns TRUE if the server is at the beginning of + a generation and is in the process of initialising, and + FALSE otherwise. +
+ +
+ +
+ + Bool xf86ServerIsOnlyProbing(); + +
+ Returns TRUE if the -probeonly command line flag + was specified, and FALSE otherwise. +
+ +
+ +
+ + Bool xf86CaughtSignal(); + +
+ Returns TRUE if the server has caught a signal, + and FALSE otherwise. +
+ +
+ + + + Allocating private data + + +A driver and any module it uses may allocate per-screen private storage +in either the ScreenRec (DIX level) or +ScrnInfoRec (XFree86 common layer level). +ScreenRec storage persists only for a single server +generation, and ScrnInfoRec storage persists across +generations for the lifetime of the server. + + + +The ScreenRec devPrivates data must be +reallocated/initialised at the start of each new generation. This is +normally done from the ChipScreenInit() function, and +Init functions for other modules that it calls. Data allocated in this +way should be freed by the driver's ChipCloseScreen() +functions, and Close functions for other modules that it calls. A new +devPrivates entry is allocated by calling the +AllocateScreenPrivateIndex() function. + + +
+ + int AllocateScreenPrivateIndex(); + +
+ This function allocates a new element in the + devPrivates field of all currently existing + ScreenRecs. The return value is the index of this + new element in the devPrivates array. The + devPrivates field is of type + DevUnion: + + + typedef union _DevUnion { + pointer ptr; + long val; + unsigned long uval; + pointer (*fptr)(void); + } DevUnion; + + + which allows the element to be used for any of the above types. + It is commonly used as a pointer to data that the caller allocates + after the new index has been allocated. + + + + This function will return -1 when there is an + error allocating the new index. + + +
+
+ + +The ScrnInfoRec privates data persists +for the life of the server, so only needs to be allocated once. This +should be done from the ChipPreInit() function, and Init +functions for other modules that it calls. Data allocated in this way +should be freed by the driver's ChipFreeScreen() functions, +and Free functions for other modules that it calls. A new +privates entry is allocated by calling the +xf86AllocateScrnInfoPrivateIndex() function. + + +
+ + int xf86AllocateScrnInfoPrivateIndex(); + +
+ This function allocates a new element in the privates + field of all currently existing ScrnInfoRecs. + The return value is the index of this new element in the + privates array. The privates + field is of type DevUnion: + + + typedef union _DevUnion { + pointer ptr; + long val; + unsigned long uval; + pointer (*fptr)(void); + } DevUnion; + + + which allows the element to be used for any of the above types. + It is commonly used as a pointer to data that the caller allocates + after the new index has been allocated. + + + + This function will not return when there is an error allocating + the new index. When there is an error it will cause the server + to exit with a fatal error. The similar function for allocation + privates in the ScreenRec + (AllocateScreenPrivateIndex()) differs in this + respect by returning -1 when the allocation fails. + + +
+
+ + + + + Keeping Track of Bus Resources + + + Theory of Operation + + +The XFree86 common layer has knowledge of generic access control mechanisms +for devices on certain bus systems (currently the PCI bus) as well as +of methods to enable or disable access to the buses itself. Furthermore +it can access information on resources decoded by these devices and if +necessary modify it. + + + +When first starting the Xserver collects all this information, saves it +for restoration, checks it for consistency, and if necessary, corrects +it. Finally it disables all resources on a generic level prior to +calling any driver function. + + + +When the Probe() function of each driver is called the +device sections are matched against the devices found in the system. +The driver may probe devices at this stage that cannot be identified by +using device independent methods. Access to all resources that can be +controlled in a device independent way is disabled. The +Probe() function should register all non-relocatable +resources at this stage. If a resource conflict is found between +exclusive resources the driver will fail immediately. Optionally the +driver might specify an EntityInit(), +EntityLeave() and EntityEnter() function. + + + +EntityInit() can be used to disable any shared resources +that are not controlled by the generic access control functions. It is +called prior to the PreInit phase regardless if an entity is active or +not. When calling the EntityInit(), +EntityEnter() and EntityLeave() functions +the common level will disable access to all other entities on a generic +level. Since the common level has no knowledge of device specific +methods to disable access to resources it cannot be guaranteed that +certain resources are not decoded by any other entity until the +EntityInit() or EntityEnter() phase is +finished. Device drivers should therefore register all those resources +which they are going to disable. If these resources are never to be +used by any driver function they may be flagged ResInit +so that they can be removed from the resource list after processing all +EntityInit() functions. EntityEnter() +should disable decoding of all resources which are not registered as +exclusive and which are not handled by the generic access control in +the common level. The difference to EntityInit() is +that the latter one is only called once during lifetime of the server. +It can therefore be used to set up variables prior to disabling resources. +EntityLeave() should restore the original state when +exiting the server or switching to a different VT. It also needs to +disable device specific access functions if they need to be disabled on +server exit or VT switch. The default state is to enable them before +giving up the VT. + + + +In PreInit() phase each driver should check if any +sharable resources it has registered during Probe() has +been denied and take appropriate action which could simply be to fail. +If it needs to access resources it has disabled during +EntitySetup() it can do so provided it has registered +these and will disable them before returning from +PreInit(). This also applies to all other driver +functions. Several functions are provided to request resource ranges, +register these, correct PCI config space and add replacements for the +generic access functions. Resources may be marked disabled or +unused during OPERATING stage. Although these steps could also be +performed in ScreenInit(), this is not desirable. + + + +Following PreInit() phase the common level determines +if resource access control is needed. This is the case if more than +one screen is used. If necessary the RAC wrapper module is loaded. In +ScreenInit() the drivers can decide which operations +need to be placed under RAC. Available are the frame buffer operations, +the pointer operations and the colormap operations. Any operation that +requires resources which might be disabled during OPERATING state should +be set to use RAC. This can be specified separately for memory and IO +resources. + + + +When ScreenInit() phase is done the common level will +determine which shared resources are requested by more than one driver +and set the access functions accordingly. This is done following these +rules: + + + + The sharable resources registered by each entity are compared. If + a resource is registered by more than one entity the entity will be + marked to need to share this resources type (IO or + MEM). + + + + A resource marked disabled during OPERATING state will be ignored + entirely. + + + + A resource marked unused will only conflicts with an overlapping + resource of an other entity if the second is actually in use during + OPERATING state. + + + + If an unused resource was found to conflict however the entity + does not use any other resource of this type the entire resource type + will be disabled for that entity. + + + + + +The driver has the choice among different ways to control access to +certain resources: + + + + It can rely on the generic access functions. This is probably the + most common case. Here the driver only needs to register any resource + it is going to use. + + + + It can replace the generic access functions by driver specific + ones. This will mostly be used in cases where no generic access + functions are available. In this case the driver has to make sure + these resources are disabled when entering the PreInit() + stage. Since the replacement functions are registered in + PreInit() the driver will have to enable these + resources itself if it needs to access them during this state. The + driver can specify if the replacement functions can control memory + and/or I/O resources separately. + + + + The driver can enable resources itself when it needs them. Each + driver function enabling them needs to disable them before it will + return. This should be used if a resource which can be controlled + in a device dependent way is only required during SETUP state. This + way it can be marked unused during OPERATING state. + + + + + +A resource which is decoded during OPERATING state however never accessed +by the driver should be marked unused. + + + +Since access switching latencies are an issue during Xserver operation, +the common level attempts to minimize the number of entities that need +to be placed under RAC control. When a wrapped operation is called, +the EnableAccess() function is called before control is +passed on. EnableAccess() checks if a screen is under +access control. If not it just establishes bus routing and returns. +If the screen needs to be under access control, +EnableAccess() determines which resource types +(MEM, IO) are required. Then it tests +if this access is already established. If so it simply returns. If +not it disables the currently established access, fixes bus routing and +enables access to all entities registered for this screen. + + + +Whenever a mode switch or a VT-switch is performed the common level will +return to SETUP state. + + + + + Resource Types + + +Resource have certain properties. When registering resources each range +is accompanied by a flag consisting of the ORed flags of the different +properties the resource has. Each resource range may be classified +according to + + + + its physical properties i.e., if it addresses + memory (ResMem) or + I/O space (ResIo), + + + if it addresses a + block (ResBlock) or + sparse (ResSparse) + range, + + + its access properties. + + + + + +There are two known access properties: + + + + ResExclusive + for resources which may not be shared with any other device and + + + ResShared + for resources which can be disabled and therefore can be shared. + + + + + +If it is necessary to test a resource against any type a generic access +type ResAny is provided. If this is set the resource +will conflict with any resource of a different entity intersecting its +range. Further it can be specified that a resource is decoded however +never used during any stage (ResUnused) or during +OPERATING state (ResUnusedOpr). A resource only visible +during the init functions (ie. EntityInit(), +EntityEnter() and EntityLeave() should +be registered with the flag ResInit. A resource that +might conflict with background resource ranges may be flagged with +ResBios. This might be useful when registering resources +ranges that were assigned by the system Bios. + + + +Several predefined resource lists are available for VGA and 8514/A +resources in common/xf86Resources.h. + + + + + Available Functions + + +The functions provided for resource management are listed in their order +of use in the driver. + + + + Probe Phase + + +In this phase each driver detects those resources it is able to drive, +creates an entity record for each of them, registers non-relocatable +resources and allocates screens and adds the resources to screens. + + + +Two helper functions are provided for matching device sections in the +xorg.conf file to the devices: + + +
+ + int xf86MatchPciInstances(const char *driverName, int vendorID, + SymTabPtr chipsets, PciChipsets *PCIchipsets, + GDevPtr *devList, int numDevs, DriverPtr drvp, + int **foundEntities); + +
+ This function finds matches between PCI cards that a driver supports + and config file device sections. It is intended for use in the + ChipProbe() function of drivers for PCI cards. + Only probed PCI devices with a vendor ID matching + vendorID are considered. devList + and numDevs are typically those found from + calling xf86MatchDevice(), and represent the active + config file device sections relevant to the driver. + PCIchipsets is a table that provides a mapping + between the PCI device IDs, the driver's internal chipset tokens + and a list of fixed resources. + + + + When a device section doesn't have a BusID entry it + can only match the primary video device. Secondary devices are + only matched with device sections that have a matching + BusID entry. + + + + Once the preliminary matches have been found, a final match is + confirmed by checking if the chipset override, ChipID override or + probed PCI chipset type match one of those given in the + chipsets and PCIchipsets lists. + The PCIchipsets list includes a list of the PCI + device IDs supported by the driver. The list should be terminated + with an entry with PCI ID -1". The + chipsets list is a table mapping the driver's + internal chipset tokens to names, and should be terminated with + a NULL entry. Only those entries with a + corresponding entry in the PCIchipsets list are + considered. The order of precedence is: config file chipset, + config file ChipID, probed PCI device ID. + + + + In cases where a driver handles PCI chipsets with more than one + vendor ID, it may set vendorID to + 0, and OR each devID in the list with (the + vendor ID << 16). + + + + Entity index numbers for confirmed matches are returned as an + array via foundEntities. The PCI information, + chipset token and device section for each match are found in the + EntityInfoRec referenced by the indices. + + + + The function return value is the number of confirmed matches. A + return value of -1 indicates an internal error. + The returned foundEntities array should be freed + by the driver with xfree() when it is no longer + needed in cases where the return value is greater than zero. + + +
+ +
+ + int xf86MatchIsaInstances(const char *driverName, + SymTabPtr chipsets, IsaChipsets *ISAchipsets, + DriverPtr drvp, FindIsaDevProc FindIsaDevice, + GDevPtr *devList, int numDevs, + int **foundEntities); + +
+ This function finds matches between ISA cards that a driver supports + and config file device sections. It is intended for use in the + ChipProbe() function of drivers for ISA cards. + devList and numDevs are + typically those found from calling xf86MatchDevice(), + and represent the active config file device sections relevant to + the driver. ISAchipsets is a table that provides + a mapping between the driver's internal chipset tokens and the + resource classes. FindIsaDevice is a + driver-provided function that probes the hardware and returns the + chipset token corresponding to what was detected, and + -1 if nothing was detected. + + + + If the config file device section contains a chipset entry, then + it is checked against the chipsets list. When + no chipset entry is present, the FindIsaDevice + function is called instead. + + + + Entity index numbers for confirmed matches are returned as an + array via foundEntities. The chipset token and + device section for each match are found in the + EntityInfoRec referenced by the indices. + + + + The function return value is the number of confirmed matches. A + return value of -1 indicates an internal error. + The returned foundEntities array should be freed + by the driver with xfree() when it is no longer + needed in cases where the return value is greater than zero. + + +
+ + +These two helper functions make use of several core functions that are +available at the driver level: + + +
+ + Bool xf86ParsePciBusString(const char *busID, int *bus, + int *device, int *func); + +
+ Takes a BusID string, and if it is in the correct + format, returns the PCI bus, device, + func values that it indicates. The format of the + string is expected to be "PCI:bus:device:func" where each of bus, + device and func are decimal integers. The ":func" part may + be omitted, and the func value assumed to be zero, but this isn't + encouraged. The "PCI" prefix may also be omitted. The prefix + "AGP" is currently equivalent to the "PCI" prefix. If the string + isn't a valid PCI BusID, the return value is FALSE. + + +
+ +
+ + Bool xf86ComparePciBusString(const char *busID, int bus, + int device, int func); + +
+ Compares a BusID string with PCI bus, + device, func values. If they + match TRUE is returned, and FALSE + if they don't. + + +
+ +
+ + Bool xf86ParseIsaBusString(const char *busID); + +
+ Compares a BusID string with the ISA bus ID string + ("ISA" or "ISA:"). If they match TRUE is returned, + and FALSE if they don't. + + +
+ +
+ + Bool xf86CheckPciSlot(int bus, int device, int func); + +
+ Checks if the PCI slot bus:device:func has been + claimed. If so, it returns FALSE, and otherwise + TRUE. + + +
+ +
+ + int xf86ClaimPciSlot(int bus, int device, int func, DriverPtr drvp, + int chipset, GDevPtr dev, Bool active); + +
+ This function is used to claim a PCI slot, allocate the associated + entity record and initialise their data structures. The return + value is the index of the newly allocated entity record, or + -1 if the claim fails. This function should always + succeed if xf86CheckPciSlot() returned + TRUE for the same PCI slot. + + +
+ +
+ + Bool xf86IsPrimaryPci(void); + +
+ This function returns TRUE if the primary card is + a PCI device, and FALSE otherwise. + + +
+ +
+ + int xf86ClaimIsaSlot(DriverPtr drvp, int chipset, + GDevPtr dev, Bool active); + +
+ This allocates an entity record entity and initialise the data + structures. The return value is the index of the newly allocated + entity record. + + +
+ +
+ + Bool xf86IsPrimaryIsa(void); + +
+ This function returns TRUE if the primary card is + an ISA (non-PCI) device, and FALSE otherwise. + + +
+ + +Two helper functions are provided to aid configuring entities: + + +
+ + ScrnInfoPtr xf86ConfigPciEntity(ScrnInfoPtr pScrn, + int scrnFlag, int entityIndex, + PciChipsets *p_chip, + resList res, EntityProc init, + EntityProc enter, EntityProc leave, + pointer private); + + ScrnInfoPtr xf86ConfigIsaEntity(ScrnInfoPtr pScrn, + int scrnFlag, int entityIndex, + IsaChipsets *i_chip, + resList res, EntityProc init, + EntityProc enter, EntityProc leave, + pointer private); + +
+ These functions are used to register the non-relocatable resources + for an entity, and the optional entity-specific Init, Enter and + Leave functions. Usually the list of fixed resources is obtained + from the Isa/PciChipsets lists. However an additional list of + resources may be passed. Generally this is not required. + For active entities a ScrnInfoRec is allocated + if the pScrn argument is NULL. +The + return value is TRUE when successful. The init, enter, leave + functions are defined as follows: + +
+ + typedef void (*EntityProc)(int entityIndex, + pointer private); + +
+ + They are passed the entity index and a pointer to a private scratch + area. This can be set up during Probe() and + its address can be passed to + xf86ConfigIsaEntity() and + xf86ConfigPciEntity() as the last argument. + + +
+ + +These two helper functions make use of several core functions that are +available at the driver level: + +
+ + void xf86ClaimFixedResources(resList list, int entityIndex); + +
+ This function registers the non-relocatable resources which cannot + be disabled and which therefore would cause the server to fail + immediately if they were found to conflict. It also records + non-relocatable but sharable resources for processing after the + Probe() phase. + + +
+ +
+ + Bool xf86SetEntityFuncs(int entityIndex, EntityProc init, + EntityProc enter, EntityProc leave, pointer); + +
+ This function registers with an entity the init, + enter, leave functions along + with the pointer to their private area. + + +
+ +
+ + void xf86AddEntityToScreen(ScrnInfoPtr pScrn, int entityIndex); + +
+ This function associates the entity referenced by + entityIndex with the screen. + + +
+ + + + + PreInit Phase + + +During this phase the remaining resources should be registered. +PreInit() should call xf86GetEntityInfo() +to obtain a pointer to an EntityInfoRec for each entity +it is able to drive and check if any resource are listed in its +resources field. If resources registered in the Probe +phase have been rejected in the post-Probe phase +(resources is non-NULL), then the driver should +decide if it can continue without using these or if it should fail. + + +
+ + EntityInfoPtr xf86GetEntityInfo(int entityIndex); + +
+ This function returns a pointer to the EntityInfoRec + referenced by entityIndex. The returned + EntityInfoRec should be freed with + xfree() when no longer needed. + + +
+ + +Several functions are provided to simplify resource registration: +
+ + Bool xf86IsEntityPrimary(int entityIndex); + +
+ This function returns TRUE if the entity referenced + by entityIndex is the primary display device (i.e., + the one initialised at boot time and used in text mode). + + +
+ +
+ + Bool xf86IsScreenPrimary(int scrnIndex); + +
+ This function returns TRUE if the primary entity + is registered with the screen referenced by + scrnIndex. + + +
+ +
+ + pciVideoPtr xf86GetPciInfoForEntity(int entityIndex); + +
+ This function returns a pointer to the pciVideoRec + for the specified entity. If the entity is not a PCI device, + NULL is returned. + + +
+ + + +The primary function for registration of resources is: +
+ + resPtr xf86RegisterResources(int entityIndex, resList list, + int access); + +
+ This function tries to register the resources in + list. If list is NULL it tries + to determine the resources automatically. This only works for + entities that provide a generic way to read out the resource ranges + they decode. So far this is only the case for PCI devices. By + default the PCI resources are registered as shared + (ResShared) if the driver wants to set a different + access type it can do so by specifying the access flags in the + third argument. A value of 0 means to use the + default settings. If for any reason the resource broker is not + able to register some of the requested resources the function will + return a pointer to a list of the failed ones. In this case the + driver may be able to move the resource to different locations. + In case of PCI bus entities this is done by passing the list of + failed resources to xf86ReallocatePciResources(). + When the registration succeeds, the return value is + NULL. + + +
+ + +
+ + resPtr xf86ReallocatePciResources(int entityIndex, resPtr pRes); + +
+ This function takes a list of PCI resources that need to be + reallocated and returns NULL when all relocations are + successful. + xf86RegisterResources() should be called again to + register the relocated resources with the broker. + If the reallocation fails, a list of the resources that could not be + relocated is returned. + + +
+ + +Two functions are provided to obtain a resource range of a given type: +
+ + resRange xf86GetBlock(long type, memType size, + memType window_start, memType window_end, + memType align_mask, resPtr avoid); + +
+ This function tries to find a block range of size + size and type type in a window + bound by window_start and window_end + with the alignment specified in align_mask. + Optionally a list of resource ranges which should be avoided within + the window can be supplied. On failure a zero-length range of + type ResEnd will be returned. + +
+ +
+ + resRange xf86GetSparse(long type, memType fixed_bits, + memType decode_mask, memType address_mask, + resPtr avoid); + +
+ This function is like the previous one, but attempts to find a + sparse range instead of a block range. Here three values have to + be specified: the address_mask which marks all + bits of the mask part of the address, the decode_mask + which masks out the bits which are hardcoded and are therefore + not available for relocation and the values of the fixed bits. + The function tries to find a base that satisfies the given condition. + If the function fails it will return a zero range of type + ResEnd. Optionally it might be passed a list of + resource ranges to avoid. + + +
+ + + +Some PCI devices are broken in the sense that they return invalid size +information for a certain resource. In this case the driver can supply +the correct size and make sure that the resource range allocated for +the card is large enough to hold the address range decoded by the card. +The function xf86FixPciResource() can be used to do this: +
+ + Bool xf86FixPciResource(int entityIndex, unsigned int prt, + CARD32 alignment, long type); + +
+ This function fixes a PCI resource allocation. The + prt parameter contains the number of the PCI base + register that needs to be fixed (0-5, and + 6 for the BIOS base register). The size is + specified by the alignment. Since PCI resources need to span an + integral range of size 2ˆn, the alignm ent also + specifies the number of addresses that will be decoded. If the + driver specifies a type mask it can override the default type for + PCI resources which is ResShared. The resource + broker needs to know that to find a matching resource range. This + function should be called before calling + xf86RegisterResources(). The return value is + TRUE when the function succeeds. + + +
+ +
+ + Bool xf86CheckPciMemBase(pciVideoPtr pPci, memType base); + +
+ This function checks that the memory base address specified matches + one of the PCI base address register values for the given PCI + device. This is mostly used to check that an externally provided + base address (e.g., from a config file) matches an actual value + allocated to a device. + + +
+ + + +The driver may replace the generic access control functions for an entity. +This is done with the xf86SetAccessFuncs(): +
+ + void xf86SetAccessFuncs(EntityInfoPtr pEnt, + xf86SetAccessFuncPtr funcs, + xf86SetAccessFuncPtr oldFuncs); + + with: + + typedef struct { + xf86AccessPtr mem; + xf86AccessPtr io; + xf86AccessPtr io_mem; + } xf86SetAccessFuncRec, *xf86SetAccessFuncPtr; + +
+ The driver can pass three functions: one for I/O access, one for + memory access and one for combined memory and I/O access. If the + memory access and combined access functions are identical the + common level assumes that the memory access cannot be controlled + independently of I/O access, if the I/O access function and the + combined access functions are the same it is assumed that I/O can + not be controlled independently. If memory and I/O have to be + controlled together all three values should be the same. If a + non NULL value is passed as third argument it is + interpreted as an address where to store the old access record. + If the third argument is NULL it will be assumed + that the generic access should be enabled before replacing the + access functions. Otherwise it will be disabled. The driver may + enable them itself using the returned values. It should do this + from its replacement access functions as the generic access may + be disabled by the common level on certain occasions. If replacement + functions are specified they must control all resources of the + specific type registered for the entity. + + +
+ + + +To find out if a specific resource range conflicts with another +resource the xf86ChkConflict() function may be used: +
+ + memType xf86ChkConflict(resRange *rgp, int entityIndex); + +
+ This function checks if the resource range rgp of + for the specified entity conflicts with with another resource. + If a conflict is found, the address of the start of the conflict + is returned. The return value is zero when there is no conflict. + + +
+ + + +The OPERATING state properties of previously registered fixed resources +can be set with the xf86SetOperatingState() function: +
+ + resPtr xf86SetOperatingState(resList list, int entityIndex, + int mask); + +
+ This function is used to set the status of a resource during + OPERATING state. list holds a list to which + mask is to be applied. The parameter + mask may have the value ResUnusedOpr + and ResDisableOpr. The first one should be used + if a resource isn't used by the driver during OPERATING state + although it is decoded by the device, while the latter one indicates + that the resource is not decoded during OPERATING state. Note + that the resource ranges have to match those specified during + registration. If a range has been specified starting at + A and ending at B and suppose + C us a value satisfying + A < C < B one may not + specify the resource range (A,B) by splitting it + into two ranges (A,C) and (C,B). + + +
+ + + +The following two functions are provided for special cases: +
+ + void xf86RemoveEntityFromScreen(ScrnInfoPtr pScrn, int entityIndex); + +
+ This function may be used to remove an entity from a screen. This + only makes sense if a screen has more than one entity assigned or + the screen is to be deleted. No test is made if the screen has + any entities left. + + +
+ +
+ + void xf86DeallocateResourcesForEntity(int entityIndex, long type); + +
+ This function deallocates all resources of a given type registered + for a certain entity from the resource broker list. + + +
+ + + + + + ScreenInit Phase + + +All that is required in this phase is to setup the RAC flags. Note that +it is also permissible to set these flags up in the PreInit phase. The +RAC flags are held in the racIoFlags and racMemFlags fields of the +ScrnInfoRec for each screen. They specify which graphics operations +might require the use of shared resources. This can be specified +separately for memory and I/O resources. The available flags are defined +in rac/xf86RAC.h. They are: + + + RAC_FB + + for framebuffer operations (including hw acceleration) + + RAC_CURSOR + + for Cursor operations + (??? I'm not sure if we need this for SW cursor it depends + on which level the sw cursor is drawn) + + RAC_COLORMAP + + for colormap operations + + RAC_VIEWPORT + + for the call to ChipAdjustFrame() + + + + +The flags are ORed together. + + + + + + + Config file <quote>Option</quote> entries + + +Option entries are permitted in most sections and subsections of the +config file. There are two forms of option entries: + + + Option "option-name" + + A boolean option. + + Option "option-name" "option-value" + + An option with an arbitrary value. + + + + + +The option entries are handled by the parser, and a list of the parsed +options is included with each of the appropriate data structures that +the drivers have access to. The data structures used to hold the option +information are opaque to the driver, and a driver must not access the +option data directly. Instead, the common layer provides a set of +functions that may be used to access, check and manipulate the option +data. + + + +First, the low level option handling functions. In most cases drivers +would not need to use these directly. + + +
+ + pointer xf86FindOption(pointer options, const char *name); + +
+ Takes a list of options and an option name, and returns a handle + for the first option entry in the list matching the name. Returns + NULL if no match is found. + + +
+ +
+ + char *xf86FindOptionValue(pointer options, const char *name); + +
+ Takes a list of options and an option name, and returns the value + associated with the first option entry in the list matching the + name. If the matching option has no value, an empty string + ("") is returned. Returns NULL + if no match is found. + + +
+ +
+ + void xf86MarkOptionUsed(pointer option); + +
+ Takes a handle for an option, and marks that option as used. + + +
+ +
+ + void xf86MarkOptionUsedByName(pointer options, const char *name); + +
+ Takes a list of options and an option name and marks the first + option entry in the list matching the name as used. + + +
+ + +Next, the higher level functions that most drivers would use. + +
+ + void xf86CollectOptions(ScrnInfoPtr pScrn, pointer extraOpts); + +
+ Collect the options from each of the config file sections used by + the screen (pScrn) and return the merged list as + pScrn->options. This function requires that + pScrn->confScreen, pScrn->display, + pScrn->monitor, + pScrn->numEntities, and + pScrn->entityList are initialised. + extraOpts may optionally be set to an additional + list of options to be combined with the others. The order of + precedence for options is extraOpts, display, + confScreen, monitor, device. + + +
+ +
+ + void xf86ProcessOptions(int scrnIndex, pointer options, + OptionInfoPtr optinfo); + +
+ Processes a list of options according to the information in the + array of OptionInfoRecs (optinfo). + The resulting information is stored in the value + fields of the appropriate optinfo entries. The + found fields are set to TRUE + when an option with a value of the correct type if found, and + FALSE otherwise. The type field + is used to determine the expected value type for each option. + Each option in the list of options for which there is a name match + (but not necessarily a value type match) is marked as used. + Warning messages are printed when option values don't match the + types specified in the optinfo data. + + + + NOTE: If this function is called before a driver's screen number + is known (e.g., from the ChipProbe() function) a + scrnIndex value of -1 should be + used. + + + + NOTE 2: Given that this function stores into the + OptionInfoRecs pointed to by optinfo, + the caller should ensure the OptionInfoRecs are + (re-)initialised before the call, especially if the caller expects + to use the predefined option values as defaults. + + + + The OptionInfoRec is defined as follows: + + + typedef struct { + double freq; + int units; + } OptFrequency; + + typedef union { + unsigned long num; + char * str; + double realnum; + Bool bool; + OptFrequency freq; + } ValueUnion; + + typedef enum { + OPTV_NONE = 0, + OPTV_INTEGER, + OPTV_STRING, /* a non-empty string */ + OPTV_ANYSTR, /* Any string, including an empty one */ + OPTV_REAL, + OPTV_BOOLEAN, + OPTV_PERCENT, + OPTV_FREQ + } OptionValueType; + + typedef enum { + OPTUNITS_HZ = 1, + OPTUNITS_KHZ, + OPTUNITS_MHZ + } OptFreqUnits; + + typedef struct { + int token; + const char* name; + OptionValueType type; + ValueUnion value; + Bool found; + } OptionInfoRec, *OptionInfoPtr; + + + + OPTV_FREQ can be used for options values that are + frequencies. These values are a floating point number with an + optional unit name appended. The unit name can be one of "Hz", + "kHz", "k", "MHz", "M". The multiplier associated with the unit + is stored in freq.units, and the scaled frequency + is stored in freq.freq. When no unit is specified, + freq.units is set to 0, and + freq.freq is unscaled. + + + + OPTV_PERCENT can be used for option values that are + specified in percent (e.g. "20%"). These values are a floating point + number with a percent sign appended. If the percent sign is missing, + the parser will fail to match the value. + + + + Typical usage is to setup an array of + OptionInfoRecs with all fields initialised. + The value and found fields get + set by xf86ProcessOptions(). For cases where the + value parsing is more complex, the driver should specify + OPTV_STRING, and parse the string itself. An + example of using this option handling is included in the + Sample Driver section. + + +
+ +
+ + void xf86ShowUnusedOptions(int scrnIndex, pointer options); + +
+ Prints out warning messages for each option in the list of options + that isn't marked as used. This is intended to show options that + the driver hasn't recognised. It would normally be called near + the end of the ChipScreenInit() function, but only + when serverGeneration == 1 + +
+ +
+ + OptionInfoPtr xf86TokenToOptinfo(const OptionInfoRec *table, + int token); + +
+ Returns a pointer to the OptionInfoRec in + table with a token field matching + token. Returns NULL if no match + is found. + + +
+ +
+ + Bool xf86IsOptionSet(const OptionInfoRec *table, int token); + +
+ Returns the found field of the + OptionInfoRec in table with a + token field matching token. This + can be used for options of all types. Note that for options of + type OPTV_BOOLEAN, it isn't sufficient to check + this to determine the value of the option. Returns + FALSE if no match is found. + + +
+ +
+ + char *xf86GetOptValString(const OptionInfoRec *table, int token); + +
+ Returns the value.str field of the + OptionInfoRec in table with a + token field matching token. Returns + NULL if no match is found. + + +
+ +
+ + Bool xf86GetOptValInteger(const OptionInfoRec *table, int token, + + int *value); + +
+ Returns via *value the value.num + field of the OptionInfoRec in table + with a token field matching token. + *value is only changed when a match is found so + it can be safely initialised with a default prior to calling this + function. The function return value is as for + xf86IsOptionSet(). + + +
+ +
+ + Bool xf86GetOptValULong(const OptionInfoRec *table, int token, + unsigned long *value); + +
+ Like xf86GetOptValInteger(), except the value is + treated as an unsigned long. + + +
+ +
+ + Bool xf86GetOptValReal(const OptionInfoRec *table, int token, + double *value); + +
+ Like xf86GetOptValInteger(), except that + value.realnum is used. + + +
+ +
+ + Bool xf86GetOptValFreq(const OptionInfoRec *table, int token, + OptFreqUnits expectedUnits, double *value); + +
+ Like xf86GetOptValInteger(), except that the + value.freq data is returned. The frequency value + is scaled to the units indicated by expectedUnits. + The scaling is exact when the units were specified explicitly in + the option's value. Otherwise, the expectedUnits + field is used as a hint when doing the scaling. In this case, + values larger than 1000 are assumed to have be + specified in the next smallest units. For example, if the Option + value is "10000" and expectedUnits is OPTUNITS_MHZ, + the value returned is 10. + + +
+ +
+ + Bool xf86GetOptValBool(const OptionInfoRec *table, int token, Bool *value); + +
+ This function is used to check boolean options + (OPTV_BOOLEAN). If the function return value is + FALSE, it means the option wasn't set. Otherwise + *value is set to the boolean value indicated by + the option's value. No option value is interpreted + as TRUE. Option values meaning TRUE + are "1", "yes", "on", "true", and option values meaning + FALSE are "0", "no", "off", "false". Option names + both with the "no" prefix in their names, and with that prefix + removed are also checked and handled in the obvious way. + *value is not changed when the option isn't present. + It should normally be set to a default value before calling this + function. + + +
+ +
+ + Bool xf86ReturnOptValBool(const OptionInfoRec *table, int token, Bool def); + +
+ This function is used to check boolean options + (OPTV_BOOLEAN). If the option is set, its value + is returned. If the options is not set, the default value specified + by def is returned. The option interpretation is + the same as for xf86GetOptValBool(). + + +
+ +
+ + int xf86NameCmp(const char *s1, const char *s2); + +
+ This function should be used when comparing strings from the config + file with expected values. It works like strcmp(), + but is not case sensitive and space, tab, and _ characters + are ignored in the comparison. The use of this function isn't + restricted to parsing option values. It may be used anywhere + where this functionality required. + + +
+ + + + Modules, Drivers, Include Files and Interface Issues + + +NOTE: this section is incomplete. + + + + + Include files + + +The following include files are typically required by video drivers: + +
+ All drivers should include these: + + "xf86.h" + "xf86_OSproc.h" + "xf86_ansic.h" + "xf86Resources.h" + + Wherever inb/outb (and related things) are used the following should be + included: + + "compiler.h" + + Note: in drivers, this must be included after "xf86_ansic.h". + + + + Drivers that need to access PCI vendor/device definitions need this: + + "xf86PciInfo.h" + + + + + Drivers that need to access the PCI config space need this: + + "xf86Pci.h" + + + + + Drivers that initialise a SW cursor need this: + + "mipointer.h" + + + + + All drivers implementing backing store need this: + + "mibstore.h" + + + + + All drivers using the mi colourmap code need this: + + "micmap.h" + + + + + If a driver uses the vgahw module, it needs this: + + "vgaHW.h" + + + + + Drivers supporting VGA or Hercules monochrome screens need: + + "xf1bpp.h" + + + + + Drivers supporting VGA or EGC 16-colour screens need: + + "xf4bpp.h" + + + + + Drivers using cfb need: + + #define PSZ 8 + #include "cfb.h" + #undef PSZ + + + + + Drivers supporting bpp 16, 24 or 32 with cfb need one or more of: + + "cfb16.h" + "cfb24.h" + "cfb32.h" + + + + + If a driver uses XAA, it needs these: + + "xaa.h" + "xaalocal.h" + + + + + If a driver uses the fb manager, it needs this: + + "xf86fbman.h" + + +
+ + + +Non-driver modules should include "xf86_ansic.h" to get the correct +wrapping of ANSI C/libc functions. + + + +All modules must NOT include any system include files, or the following: + + + "xf86Priv.h" + "xf86Privstr.h" + "xf86_OSlib.h" + "Xos.h" + + + + +In addition, "xf86_libc.h" must not be included explicitly. It is +included implicitly by "xf86_ansic.h". + + + + + + + Offscreen Memory Manager + + +Management of offscreen video memory may be handled by the XFree86 +framebuffer manager. Once the offscreen memory manager is running, +drivers or extensions may allocate, free or resize areas of offscreen +video memory using the following functions (definitions taken from +xf86fbman.h): + + + typedef struct _FBArea { + ScreenPtr pScreen; + BoxRec box; + int granularity; + void (*MoveAreaCallback)(struct _FBArea*, struct _FBArea*) + void (*RemoveAreaCallback)(struct _FBArea*) + DevUnion devPrivate; + } FBArea, *FBAreaPtr; + + typedef void (*MoveAreaCallbackProcPtr)(FBAreaPtr from, FBAreaPtr to) + typedef void (*RemoveAreaCallbackProcPtr)(FBAreaPtr) + + FBAreaPtr xf86AllocateOffscreenArea ( + ScreenPtr pScreen, + int width, int height, + int granularity, + MoveAreaCallbackProcPtr MoveAreaCallback, + RemoveAreaCallbackProcPtr RemoveAreaCallback, + pointer privData + ) + + void xf86FreeOffscreenArea (FBAreaPtr area) + + Bool xf86ResizeOffscreenArea ( + FBAreaPtr area + int w, int h + ) + + + + +The function: + + Bool xf86FBManagerRunning(ScreenPtr pScreen); + + +can be used by an extension to check if the driver has initialized +the memory manager. The manager is not available if this returns +FALSE and the functions above will all fail. + + + + +xf86AllocateOffscreenArea() can be used to request a +rectangle of dimensions width × height +(in pixels) from unused offscreen memory. granularity +specifies that the leftmost edge of the rectangle must lie on some +multiple of granularity pixels. A granularity of zero +means the same thing as a granularity of one - no alignment preference. +A MoveAreaCallback can be provided to notify the requester +when the offscreen area is moved. If no MoveAreaCallback +is supplied then the area is considered to be immovable. The +privData field will be stored in the manager's internal +structure for that allocated area and will be returned to the requester +in the FBArea passed via the +MoveAreaCallback. An optional +RemoveAreaCallback is provided. If the driver provides +this it indicates that the area should be allocated with a lower priority. +Such an area may be removed when a higher priority request (one that +doesn't have a RemoveAreaCallback) is made. When this +function is called, the driver will have an opportunity to do whatever +cleanup it needs to do to deal with the loss of the area, but it must +finish its cleanup before the function exits since the offscreen memory +manager will free the area immediately after. + + + +xf86AllocateOffscreenArea() returns NULL +if it was unable to allocate the requested area. When no longer needed, +areas should be freed with xf86FreeOffscreenArea(). + + + +xf86ResizeOffscreenArea() resizes an existing +FBArea. xf86ResizeOffscreenArea() +returns TRUE if the resize was successful. If +xf86ResizeOffscreenArea() returns FALSE, +the original FBArea is left unmodified. Resizing an +area maintains the area's original granularity, +devPrivate, and MoveAreaCallback. +xf86ResizeOffscreenArea() has considerably less overhead +than freeing the old area then reallocating the new size, so it should +be used whenever possible. + + + +The function: + + Bool xf86QueryLargestOffscreenArea( + ScreenPtr pScreen, + int *width, int *height, + int granularity, + int preferences, + int priority + ); + + +is provided to query the width and height of the largest single +FBArea allocatable given a particular priority. +preferences can be one of the following to indicate +whether width, height or area should be considered when determining +which is the largest single FBArea available. + + + FAVOR_AREA_THEN_WIDTH + FAVOR_AREA_THEN_HEIGHT + FAVOR_WIDTH_THEN_AREA + FAVOR_HEIGHT_THEN_AREA + + + + +priority is one of the following: + +
+ + PRIORITY_LOW +
+ Return the largest block available without stealing anyone else's + space. This corresponds to the priority of allocating a + FBArea when a RemoveAreaCallback + is provided. +
+ + + + PRIORITY_NORMAL +
+ Return the largest block available if it is acceptable to steal a + lower priority area from someone. This corresponds to the priority + of allocating a FBArea without providing a + RemoveAreaCallback. +
+ + + + PRIORITY_EXTREME +
+ Return the largest block available if all FBAreas + that aren't locked down were expunged from memory first. This + corresponds to any allocation made directly after a call to + xf86PurgeUnlockedOffscreenAreas(). +
+ + +
+ + + + +The function: + + + Bool xf86PurgeUnlockedOffscreenAreas(ScreenPtr pScreen); + + +is provided as an extreme method to free up offscreen memory. This +will remove all removable FBArea allocations. + + + + +Initialization of the XFree86 framebuffer manager is done via + + + Bool xf86InitFBManager(ScreenPtr pScreen, BoxPtr FullBox); + + +FullBox represents the area of the framebuffer that the +manager is allowed to manage. This is typically a box with a width of +pScrn->displayWidth and a height of as many lines as +can be fit within the total video memory, however, the driver can reserve +areas at the extremities by passing a smaller area to the manager. + + + +xf86InitFBManager() must be called before XAA is +initialized since XAA uses the manager for it's pixmap cache. + + + +An alternative function is provided to allow the driver to initialize +the framebuffer manager with a Region rather than a box. + + + Bool xf86InitFBManagerRegion(ScreenPtr pScreen, + RegionPtr FullRegion); + + +xf86InitFBManagerRegion(), unlike +xf86InitFBManager(), does not remove the area used for +the visible screen so that area should not be included in the region +passed to the function. xf86InitFBManagerRegion() is +useful when non-contiguous areas are available to be managed, and is +required when multiple framebuffers are stored in video memory (as in +the case where an overlay of a different depth is stored as a second +framebuffer in offscreen memory). + + + + + + Colormap Handling + + +A generic colormap handling layer is provided within the XFree86 common +layer. This layer takes care of most of the details, and only requires +a function from the driver that loads the hardware palette when required. +To use the colormap layer, a driver calls the +xf86HandleColormaps() function. + +
+ + Bool xf86HandleColormaps(ScreenPtr pScreen, int maxColors, + int sigRGBbits, LoadPaletteFuncPtr loadPalette, + SetOverscanFuncPtr setOverscan, + unsigned int flags); + +
+ This function must be called after the default colormap has been + initialised. The pScrn->gamma field must also + be initialised, preferably by calling xf86SetGamma(). + maxColors is the number of entries in the palette. + sigRGBbits is the size in bits of each color + component in the DAC's palette. loadPalette + is a driver-provided function for loading a colormap into the + hardware, and is described below. setOverscan is + an optional function that may be provided when the overscan color + is an index from the standard LUT and when it needs to be adjusted + to keep it as close to black as possible. The + setOverscan function programs the overscan index. + It shouldn't normally be used for depths other than 8. + setOverscan should be set to NULL + when it isn't needed. flags may be set to the + following (which may be ORed together): + + + + CMAP_PALETTED_TRUECOLOR + + the TrueColor visual is paletted and is + just a special case of DirectColor. + This flag is only valid for + bpp > 8. + + + + CMAP_RELOAD_ON_MODE_SWITCH + + reload the colormap automatically + after mode switches. This is useful + for when the driver is resetting the + hardware during mode switches and + corrupting or erasing the hardware + palette. + + + + CMAP_LOAD_EVEN_IF_OFFSCREEN + + reload the colormap even if the screen + is switched out of the server's VC. + The palette is not reloaded when + the screen is switched back in, nor after + mode switches. This is useful when the + driver needs to keep track of palette + changes. + + + + + + + The colormap layer normally reloads the palette after VT enters so it + is not necessary for the driver to save and restore the palette + when switching VTs. The driver must, however, still save the + initial palette during server start up and restore it during + server exit. + + +
+ +
+ + void LoadPalette(ScrnInfoPtr pScrn, int numColors, int *indices, + LOCO *colors, VisualPtr pVisual); + +
+ LoadPalette() is a driver-provided function for + loading a colormap into hardware. colors is the + array of RGB values that represent the full colormap. + indices is a list of index values into the colors + array. These indices indicate the entries that need to be updated. + numColors is the number of the indices to be + updated. + + +
+ +
+ + void SetOverscan(ScrnInfoPtr pScrn, int overscan); + +
+ SetOverscan() is a driver-provided function for + programming the overscan index. As described + above, it is normally only appropriate for LUT modes where all + colormap entries are available for the display, but where one of + them is also used for the overscan (typically 8bpp for VGA compatible + LUTs). It isn't required in cases where the overscan area is + never visible. + + +
+
+ + + + + DPMS Extension + + +Support code for the DPMS extension is included in the XFree86 common layer. +This code provides an interface between the main extension code, and a means +for drivers to initialise DPMS when they support it. One function is +available to drivers to do this initialisation, and it is always available, +even when the DPMS extension is not supported by the core server (in +which case it returns a failure result). + + +
+ + Bool xf86DPMSInit(ScreenPtr pScreen, DPMSSetProcPtr set, int flags); + +
+ This function registers a driver's DPMS level programming function + set. It also checks + pScrn->options for the "dpms" option, and when + present marks DPMS as being enabled for that screen. The + set function is called whenever the DPMS level + changes, and is used to program the requested level. + flags is currently not used, and should be + 0. If the initialisation fails for any reason, + including when there is no DPMS support in the core server, the + function returns FALSE. + + +
+ + + +Drivers that implement DPMS support must provide the following function, +that gets called when the DPMS level is changed: + + +
+ + void ChipDPMSSet(ScrnInfoPtr pScrn, int level, int flags); + +
+ Program the DPMS level specified by level. Valid + values of level are DPMSModeOn, + DPMSModeStandby, DPMSModeSuspend, + DPMSModeOff. These values are defined in + "extensions/dpms.h". + + +
+ + + + + + DGA Extension + + +Drivers can support the XFree86 Direct Graphics Architecture (DGA) by +filling out a structure of function pointers and a list of modes and +passing them to DGAInit. + + +
+ + Bool DGAInit(ScreenPtr pScreen, DGAFunctionPtr funcs, + DGAModePtr modes, int num); + +/** The DGAModeRec **/ + +typedef struct { + int num; + DisplayModePtr mode; + int flags; + int imageWidth; + int imageHeight; + int pixmapWidth; + int pixmapHeight; + int bytesPerScanline; + int byteOrder; + int depth; + int bitsPerPixel; + unsigned long red_mask; + unsigned long green_mask; + unsigned long blue_mask; + int viewportWidth; + int viewportHeight; + int xViewportStep; + int yViewportStep; + int maxViewportX; + int maxViewportY; + int viewportFlags; + int offset; + unsigned char *address; + int reserved1; + int reserved2; +} DGAModeRec, *DGAModePtr; + + + + + num + + Can be ignored. The DGA DDX will assign these numbers. + + + + mode + + A pointer to the DisplayModeRec for this mode. + + + + flags + + The following flags are defined and may be OR'd together: + + + + DGA_CONCURRENT_ACCESS + + Indicates that the driver supports concurrent graphics + accelerator and linear framebuffer access. + + + + + DGA_FILL_RECT + DGA_BLIT_RECT + DGA_BLIT_RECT_TRANS + + Indicates that the driver supports the FillRect, BlitRect + or BlitTransRect functions in this mode. + + + + + DGA_PIXMAP_AVAILABLE + + Indicates that Xlib may be used on the framebuffer. + This flag will usually be set unless the driver wishes + to prohibit this for some reason. + + + + + DGA_INTERLACED + DGA_DOUBLESCAN + + Indicates that these are interlaced or double scan modes. + + + + + + + imageWidth + imageHeight + + These are the dimensions of the linear framebuffer + accessible by the client. + + + + + pixmapWidth + pixmapHeight + + These are the dimensions of the area of the + framebuffer accessible by the graphics accelerator. + + + + + bytesPerScanline + + Pitch of the framebuffer in bytes. + + + + + byteOrder + + Usually the same as + pScrn->imageByteOrder. + + + + + depth + + The depth of the framebuffer in this mode. + + + + + bitsPerPixel + + The number of bits per pixel in this mode. + + + + + red_mask + green_mask + blue_mask + + The RGB masks for this mode, if applicable. + + + + + viewportWidth + viewportHeight + + Dimensions of the visible part of the framebuffer. + Usually mode->HDisplay and + mode->VDisplay. + + + + + xViewportStep + yViewportStep + + The granularity of x and y viewport positions that + the driver supports in this mode. + + + + + maxViewportX + maxViewportY + + The maximum viewport position supported by the + driver in this mode. + + + + viewportFlags + + The following may be OR'd together: + + + + DGA_FLIP_IMMEDIATE + + The driver supports immediate viewport changes. + + + + DGA_FLIP_RETRACE + + + The driver supports viewport changes at retrace. + + + + + + offset + + The offset into the linear framebuffer that corresponds to + pixel (0,0) for this mode. + + + + address + + The virtual address of the framebuffer as mapped by the driver. + This is needed when DGA_PIXMAP_AVAILABLE is set. + + + + + +/** The DGAFunctionRec **/ + +typedef struct { + Bool (*OpenFramebuffer)( + ScrnInfoPtr pScrn, + char **name, + unsigned char **mem, + int *size, + int *offset, + int *extra + ); + void (*CloseFramebuffer)(ScrnInfoPtr pScrn); + Bool (*SetMode)(ScrnInfoPtr pScrn, DGAModePtr pMode); + void (*SetViewport)(ScrnInfoPtr pScrn, int x, int y, int flags); + int (*GetViewport)(ScrnInfoPtr pScrn); + void (*Sync)(ScrnInfoPtr); + void (*FillRect)( + ScrnInfoPtr pScrn, + int x, int y, int w, int h, + unsigned long color + ); + void (*BlitRect)( + ScrnInfoPtr pScrn, + int srcx, int srcy, + int w, int h, + int dstx, int dsty + ); + void (*BlitTransRect)( + ScrnInfoPtr pScrn, + int srcx, int srcy, + int w, int h, + int dstx, int dsty, + unsigned long color + ); +} DGAFunctionRec, *DGAFunctionPtr; + + + +
+ + Bool OpenFramebuffer (pScrn, name, mem, size, offset, extra); + +
+ OpenFramebuffer() should pass the client everything + it needs to know to be able to open the framebuffer. These + parameters are OS specific and their meanings are to be interpreted + by an OS specific client library. + + + + name + + The name of the device to open or NULL if + there is no special device to open. A NULL + name tells the client that it should open whatever device + one would usually open to access physical memory. + + + + mem + + The physical address of the start of the framebuffer. + + + + size + + The size of the framebuffer in bytes. + + + + offset + + Any offset into the device, if applicable. + + + + flags + + Any additional information that the client may need. + Currently, only the DGA_NEED_ROOT flag is + defined. + + + +
+
+ +
+ + void CloseFramebuffer (pScrn); + +
+ CloseFramebuffer() merely informs the driver (if it + even cares) that client no longer needs to access the framebuffer + directly. This function is optional. + + +
+ +
+ + Bool SetMode (pScrn, pMode); + +
+ SetMode() tells the driver to initialize the mode + passed to it. If pMode is NULL, + then the driver should restore the original pre-DGA mode. + + +
+ +
+ + void SetViewport (pScrn, x, y, flags); + +
+ SetViewport() tells the driver to make the upper + left-hand corner of the visible screen correspond to coordinate + (x,y) on the framebuffer. flags + currently defined are: + + + + DGA_FLIP_IMMEDIATE + + The viewport change should occur immediately. + + + + DGA_FLIP_RETRACE + + The viewport change should occur at the + vertical retrace, but this function should + return sooner if possible. + + + + + + The (x,y) locations will be passed as the client + specified them, however, the driver is expected to round these + locations down to the next supported location as specified by the + xViewportStep and yViewportStep + for the current mode. + +
+ +
+ + int GetViewport (pScrn); + +
+ GetViewport() gets the current page flip status. + Set bits in the returned int correspond to viewport change requests + still pending. For instance, set bit zero if the last SetViewport + request is still pending, bit one if the one before that is still + pending, etc. + + +
+ +
+ + void Sync (pScrn); + +
+ This function should ensure that any graphics accelerator operations + have finished. This function should not return until the graphics + accelerator is idle. + + +
+ +
+ + void FillRect (pScrn, x, y, w, h, color); + +
+ This optional function should fill a rectangle + w × h located at + (x,y) in the given color. + + +
+ +
+ + void BlitRect (pScrn, srcx, srcy, w, h, dstx, dsty); + +
+ This optional function should copy an area + w × h located at + (srcx,srcy) to location (dstx,dsty). + This function will need to handle copy directions as appropriate. + + +
+ +
+ + void BlitTransRect (pScrn, srcx, srcy, w, h, dstx, dsty, color); + +
+ This optional function is the same as BlitRect except that pixels + in the source corresponding to the color key color + should be skipped. + + +
+
+ + + + + The XFree86 X Video Extension (Xv) Device Dependent Layer + + +XFree86 offers the X Video Extension which allows clients to treat video +as any another primitive and Put video into drawables. By default, +the extension reports no video adaptors as being available since the +DDX layer has not been initialized. The driver can initialize the DDX +layer by filling out one or more XF86VideoAdaptorRecs +as described later in this document and passing a list of +XF86VideoAdaptorPtr pointers to the following function: + + + Bool xf86XVScreenInit(ScreenPtr pScreen, + XF86VideoAdaptorPtr *adaptPtrs, + int num); + + + + +After doing this, the extension will report video adaptors as being +available, providing the data in their respective +XF86VideoAdaptorRecs was valid. +xf86XVScreenInit() copies data from the structure +passed to it so the driver may free it after the initialization. At +the moment, the DDX only supports rendering into Window drawables. +Pixmap rendering will be supported after a sufficient survey of suitable +hardware is completed. + + + +The XF86VideoAdaptorRec: + + +typedef struct { + unsigned int type; + int flags; + char *name; + int nEncodings; + XF86VideoEncodingPtr pEncodings; + int nFormats; + XF86VideoFormatPtr pFormats; + int nPorts; + DevUnion *pPortPrivates; + int nAttributes; + XF86AttributePtr pAttributes; + int nImages; + XF86ImagePtr pImages; + PutVideoFuncPtr PutVideo; + PutStillFuncPtr PutStill; + GetVideoFuncPtr GetVideo; + GetStillFuncPtr GetStill; + StopVideoFuncPtr StopVideo; + SetPortAttributeFuncPtr SetPortAttribute; + GetPortAttributeFuncPtr GetPortAttribute; + QueryBestSizeFuncPtr QueryBestSize; + PutImageFuncPtr PutImage; + QueryImageAttributesFuncPtr QueryImageAttributes; +} XF86VideoAdaptorRec, *XF86VideoAdaptorPtr; + + + +Each adaptor will have its own XF86VideoAdaptorRec. The fields are +as follows: + + + + type + + This can be any of the following flags OR'd together. + + + + XvInputMask + XvOutputMask + + These refer to the target drawable and are similar to a Window's + class. XvInputMask indicates that the adaptor + can put video into a drawable. XvOutputMask + indicates that the adaptor can get video from a drawable. + + + + XvVideoMask + XvStillMask + XvImageMask + + These indicate that the adaptor supports video, still or + image primitives respectively. + + + + XvWindowMask + XvPixmapMask + + These indicate the types of drawables the adaptor is capable + of rendering into. At the moment, Pixmap rendering is not + supported and the XvPixmapMask flag is ignored. + + + + + + + flags + + Currently, the following flags are defined: + + + + VIDEO_NO_CLIPPING + + This indicates that the video adaptor does not support + clipping. The driver will never receive Put requests + where less than the entire area determined by + drw_x, drw_y, + drw_w and drw_h is visible. + This flag does not apply to Get requests. Hardware + that is incapable of clipping Gets may punt or get + the extents of the clipping region passed to it. + + + + + + VIDEO_INVERT_CLIPLIST + + This indicates that the video driver requires the clip + list to contain the regions which are obscured rather + than the regions which are are visible. + + + + + + VIDEO_OVERLAID_STILLS + + Implementing PutStill for hardware that does video as an + overlay can be awkward since it's unclear how long to leave + the video up for. When this flag is set, StopVideo will be + called whenever the destination gets clipped or moved so that + the still can be left up until then. + + + + + + VIDEO_OVERLAID_IMAGES + + Same as VIDEO_OVERLAID_STILLS but for images. + + + + + VIDEO_CLIP_TO_VIEWPORT + + Indicates that the clip region passed to the driver functions + should be clipped to the visible portion of the screen in the + case where the viewport is smaller than the virtual desktop. + + + + + + + name + + The name of the adaptor. + + + + + nEncodings + pEncodings + + The number of encodings the adaptor is capable of and pointer + to the XF86VideoEncodingRec array. The + XF86VideoEncodingRec is described later on. + For drivers that only support XvImages there should be an encoding + named "XV_IMAGE" and the width and height should specify + the maximum size source image supported. + + + + + nFormats + pFormats + + The number of formats the adaptor is capable of and pointer to + the XF86VideoFormatRec array. The + XF86VideoFormatRec is described later on. + + + + + nPorts + pPortPrivates + + The number of ports is the number of separate data streams which + the adaptor can handle simultaneously. If you have more than + one port, the adaptor is expected to be able to render into more + than one window at a time. pPortPrivates is + an array of pointers or ints - one for each port. A port's + private data will be passed to the driver any time the port is + requested to do something like put the video or stop the video. + In the case where there may be many ports, this enables the + driver to know which port the request is intended for. Most + commonly, this will contain a pointer to the data structure + containing information about the port. In Xv, all ports on + a particular adaptor are expected to be identical in their + functionality. + + + + + nAttributes + pAttributes + + The number of attributes recognized by the adaptor and a pointer to + the array of XF86AttributeRecs. The + XF86AttributeRec is described later on. + + + + + nImages + pImages + + The number of XF86ImageRecs supported by the adaptor + and a pointer to the array of XF86ImageRecs. The + XF86ImageRec is described later on. + + + + + + PutVideo PutStill GetVideo GetStill StopVideo + SetPortAttribute GetPortAttribute QueryBestSize PutImage + QueryImageAttributes + + + These functions define the DDX->driver interface. In each + case, the pointer data is passed to the driver. + This is the port private for that port as described above. All + fields are required except under the following conditions: + + + + PutVideo, PutStill and + the image routines PutImage and + QueryImageAttributes are not required when the + adaptor type does not contain XvInputMask. + + + + GetVideo and GetStill + are not required when the adaptor type does not contain + XvOutputMask. + + + + GetVideo and PutVideo + are not required when the adaptor type does not contain + XvVideoMask. + + + + GetStill and PutStill + are not required when the adaptor type does not contain + XvStillMask. + + + + PutImage and QueryImageAttributes + are not required when the adaptor type does not contain + XvImageMask. + + + + + + + + With the exception of QueryImageAttributes, these + functions should return Success if the operation was + completed successfully. They can return XvBadAlloc + otherwise. QueryImageAttributes returns the size + of the XvImage queried. + + + + If the VIDEO_NO_CLIPPING + flag is set, the clipBoxes may be ignored by + the driver. ClipBoxes is an X-Y + banded region identical to those used throughout the server. + The clipBoxes represent the visible portions of the area determined + by drw_x, drw_y, + drw_w and drw_h in the Get/Put + function. The boxes are in screen coordinates, are guaranteed + not to overlap and an empty region will never be passed. + If the driver has specified VIDEO_INVERT_CLIPLIST, + clipBoxes will indicate the areas of the primitive + which are obscured rather than the areas visible. + + + + +
+ + typedef int (* PutVideoFuncPtr)( ScrnInfoPtr pScrn, + short vid_x, short vid_y, short drw_x, short drw_y, + short vid_w, short vid_h, short drw_w, short drw_h, + RegionPtr clipBoxes, pointer data ); + +
+ This indicates that the driver should take a subsection + vid_w by vid_h at location + (vid_x,vid_y) from the video stream and direct + it into the rectangle drw_w by drw_h + at location (drw_x,drw_y) on the screen, scaling as + necessary. Due to the large variations in capabilities of + the various hardware expected to be used with this extension, + it is not expected that all hardware will be able to do this + exactly as described. In that case the driver should just do + the best it can, scaling as closely to the target rectangle + as it can without rendering outside of it. In the worst case, + the driver can opt to just not turn on the video. + + +
+ +
+ + typedef int (* PutStillFuncPtr)( ScrnInfoPtr pScrn, + short vid_x, short vid_y, short drw_x, short drw_y, + short vid_w, short vid_h, short drw_w, short drw_h, + RegionPtr clipBoxes, pointer data ); + +
+ This is same as PutVideo except that the driver + should place only one frame from the stream on the screen. + + +
+ +
+ + typedef int (* GetVideoFuncPtr)( ScrnInfoPtr pScrn, + short vid_x, short vid_y, short drw_x, short drw_y, + short vid_w, short vid_h, short drw_w, short drw_h, + RegionPtr clipBoxes, pointer data ); + +
+ This is same as PutVideo except that the driver + gets video from the screen and outputs it. The driver should + do the best it can to get the requested dimensions correct + without reading from an area larger than requested. + + +
+ +
+ + typedef int (* GetStillFuncPtr)( ScrnInfoPtr pScrn, + short vid_x, short vid_y, short drw_x, short drw_y, + short vid_w, short vid_h, short drw_w, short drw_h, + RegionPtr clipBoxes, pointer data ); + +
+ This is the same as GetVideo except that the + driver should place only one frame from the screen into the + output stream. + + +
+ +
+ + typedef void (* StopVideoFuncPtr)(ScrnInfoPtr pScrn, + pointer data, Bool cleanup); + +
+ This indicates the driver should stop displaying the video. + This is used to stop both input and output video. The + cleanup field indicates that the video is + being stopped because the client requested it to stop or + because the server is exiting the current VT. In that case + the driver should deallocate any offscreen memory areas (if + there are any) being used to put the video to the screen. If + cleanup is not set, the video is being stopped + temporarily due to clipping or moving of the window, etc... + and video will likely be restarted soon so the driver should + not deallocate any offscreen areas associated with that port. + + +
+
+ + typedef int (* SetPortAttributeFuncPtr)(ScrnInfoPtr pScrn, + Atom attribute,INT32 value, pointer data); + + + + typedef int (* GetPortAttributeFuncPtr)(ScrnInfoPtr pScrn, + Atom attribute,INT32 *value, pointer data); + +
+ A port may have particular attributes such as hue, + saturation, brightness or contrast. Xv clients set and + get these attribute values by sending attribute strings + (Atoms) to the server. Such requests end up at these + driver functions. It is recommended that the driver provide + at least the following attributes mentioned in the Xv client + library docs: + + XV_ENCODING + XV_HUE + XV_SATURATION + XV_BRIGHTNESS + XV_CONTRAST + + but the driver may recognize as many atoms as it wishes. If + a requested attribute is unknown by the driver it should return + BadMatch. XV_ENCODING is the + attribute intended to let the client specify which video + encoding the particular port should be using (see the description + of XF86VideoEncodingRec below). If the + requested encoding is unsupported, the driver should return + XvBadEncoding. If the value lies outside the + advertised range BadValue may be returned. + Success should be returned otherwise. + + +
+ +
+ + typedef void (* QueryBestSizeFuncPtr)(ScrnInfoPtr pScrn, + Bool motion, short vid_w, short vid_h, + short drw_w, short drw_h, + unsigned int *p_w, unsigned int *p_h, pointer data); + +
+ QueryBestSize provides the client with a way + to query what the destination dimensions would end up being + if they were to request that an area + vid_w by vid_h from the video + stream be scaled to rectangle of + drw_w by drw_h on the screen. + Since it is not expected that all hardware will be able to + get the target dimensions exactly, it is important that the + driver provide this function. + + +
+ +
+ + typedef int (* PutImageFuncPtr)( ScrnInfoPtr pScrn, + short src_x, short src_y, short drw_x, short drw_y, + short src_w, short src_h, short drw_w, short drw_h, + int image, char *buf, short width, short height, + Bool sync, RegionPtr clipBoxes, pointer data ); + +
+ This is similar to PutStill except that the + source of the video is not a port but the data stored in a system + memory buffer at buf. The data is in the format + indicated by the image descriptor and represents a + source of size width by height. + If sync is TRUE the driver should not return + from this function until it is through reading the data + from buf. Returning when sync + is TRUE indicates that it is safe for the data at buf + to be replaced, freed, or modified. + + +
+ +
+ + typedef int (* QueryImageAttributesFuncPtr)( ScrnInfoPtr pScrn, + int image, short *width, short *height, + int *pitches, int *offsets); + +
+ This function is called to let the driver specify how data for + a particular image of size width + by height should be stored. Sometimes only + the size and corrected width and height are needed. In that + case pitches and offsets are + NULL. The size of the memory required for the image is returned + by this function. The width and + height of the requested image can be altered by + the driver to reflect format limitations (such as component + sampling periods that are larger than one). If + pitches and offsets are not NULL, + these will be arrays with as many elements in them as there + are planes in the image format. The driver + should specify the pitch (in bytes) of each scanline in the + particular plane as well as the offset to that plane (in bytes) + from the beginning of the image. + + +
+ + + +The XF86VideoEncodingRec: + +
+ +typedef struct { + int id; + char *name; + unsigned short width, height; + XvRationalRec rate; +} XF86VideoEncodingRec, *XF86VideoEncodingPtr; + + +
+ The XF86VideoEncodingRec specifies what encodings + the adaptor can support. Most of this data is just informational + and for the client's benefit, and is what will be reported by + XvQueryEncodings. The id field is + expected to be a unique identifier to allow the client to request a + certain encoding via the XV_ENCODING attribute string. + + +
+ + + +The XF86VideoFormatRec: + +
+ +typedef struct { + char depth; + short class; +} XF86VideoFormatRec, *XF86VideoFormatPtr; + + +
+ This specifies what visuals the video is viewable in. + depth is the depth of the visual (not bpp). + class is the visual class such as + TrueColor, DirectColor or + PseudoColor. Initialization of an adaptor will fail + if none of the visuals on that screen are supported. + + +
+ + + +The XF86AttributeRec: + +
+ +typedef struct { + int flags; + int min_value; + int max_value; + char *name; +} XF86AttributeListRec, *XF86AttributeListPtr; + + +
+ Each adaptor may have an array of these advertising the attributes + for its ports. Currently defined flags are XvGettable + and XvSettable which may be OR'd together indicating that + attribute is gettable or settable by the client. The + min and max field specify the valid range + for the value. Name is a text string describing the + attribute by name. + + +
+ + + + +The XF86ImageRec: + +
+ +typedef struct { + int id; + int type; + int byte_order; + char guid[16]; + int bits_per_pixel; + int format; + int num_planes; + + /* for RGB formats */ + int depth; + unsigned int red_mask; + unsigned int green_mask; + unsigned int blue_mask; + + /* for YUV formats */ + unsigned int y_sample_bits; + unsigned int u_sample_bits; + unsigned int v_sample_bits; + unsigned int horz_y_period; + unsigned int horz_u_period; + unsigned int horz_v_period; + unsigned int vert_y_period; + unsigned int vert_u_period; + unsigned int vert_v_period; + char component_order[32]; + int scanline_order; +} XF86ImageRec, *XF86ImagePtr; + + +
+ XF86ImageRec describes how video source data is laid out in memory. + The fields are as follows: + + + + id + + This is a unique descriptor for the format. It is often good to + set this value to the FOURCC for the format when applicable. + + + + type + + This is XvRGB or XvYUV. + + + + byte_order + + This is LSBFirst or MSBFirst. + + + + guid + + This is the Globally Unique IDentifier for the format. When + not applicable, all characters should be NULL. + + + + bits_per_pixel + + The number of bits taken up (but not necessarily used) by each + pixel. Note that for some planar formats which have fractional + bits per pixel (such as IF09) this number may be rounded _down_. + + + + format + + This is XvPlanar or XvPacked. + + + + num_planes + + The number of planes in planar formats. This should be set to + one for packed formats. + + + + depth + + The significant bits per pixel in RGB formats (analgous to the + depth of a pixmap format). + + + + red_mask + green_mask + blue_mask + + The red, green and blue bitmasks for packed RGB formats. + + + + y_sample_bits + u_sample_bits + v_sample_bits + + The y, u and v sample sizes (in bits). + + + + horz_y_period + horz_u_period + horz_v_period + + The y, u and v sampling periods in the horizontal direction. + + + + vert_y_period + vert_u_period + vert_v_period + + The y, u and v sampling periods in the vertical direction. + + + + component_order + + Uppercase ascii characters representing the order that + samples are stored within packed formats. For planar formats + this represents the ordering of the planes. Unused characters + in the 32 byte string should be set to NULL. + + + + scanline_order + + This is XvTopToBottom or XvBottomToTop. + + + + + + + Since some formats (particular some planar YUV formats) may not +be completely defined by the parameters above, the guid, when +available, should provide the most accurate description of the +format. + + +
+ + + + + The Loader + + +This section describes the interfaces to the module loader. The loader +interfaces can be divided into two groups: those that are only available to +the XFree86 common layer, and those that are also available to modules. + + + + Loader Overview + + +The loader is capable of loading modules in a range of object formats, +and knowledge of these formats is built in to the loader. Knowledge of +new object formats can be added to the loader in a straightforward +manner. This makes it possible to provide OS-independent modules (for +a given CPU architecture type). In addition to this, the loader can +load modules via the OS-provided dlopen(3) service where +available. Such modules are not platform independent, and the semantics +of dlopen() on most systems results in significant +limitations in the use of modules of this type. Support for +dlopen() modules in the loader is primarily for +experimental and development purposes. + + + +Symbols exported by the loader (on behalf of the core X server) to +modules are determined at compile time. Only those symbols explicitly +exported are available to modules. All external symbols of loaded +modules are exported to other modules, and to the core X server. The +loader can be requested to check for unresolved symbols at any time, +and the action to be taken for unresolved symbols can be controlled by +the caller of the loader. Typically the caller identifies which symbols +can safely remain unresolved and which cannot. + + + +NOTE: Now that ISO-C allows pointers to functions and pointers to data to +have different internal representations, some of the following interfaces +will need to be revisited. + + + + + Semi-private Loader Interface + + +The following is the semi-private loader interface that is available to the +XFree86 common layer. + + +
+ + void LoaderInit(void); + +
+ The LoaderInit() function initialises the loader, + and it must be called once before calling any other loader functions. + This function initialises the tables of exported symbols, and anything + else that might need to be initialised. + + +
+ +
+ + void LoaderSetPath(const char *path); + +
+ The LoaderSetPath() function initialises a default + module search path. This must be called if calls to other functions + are to be made without explicitly specifying a module search path. + The search path path must be a string of one or more + comma separated absolute paths. Modules are expected to be located + below these paths, possibly in subdirectories of these paths. + + +
+ +
+ + pointer LoadModule(const char *module, const char *path, + const char **subdirlist, const char **patternlist, + pointer options, const XF86ModReqInfo * modreq, + int *errmaj, int *errmin); + +
+ The LoadModule() function loads the module called + module. The return value is a module handle, and + may be used in future calls to the loader that require a reference + to a loaded module. The module name module is + normally the module's canonical name, which doesn't contain any + directory path information, or any object/library file prefixes of + suffixes. Currently a full pathname and/or filename is also accepted. + This might change. The other parameters are: + + + + path + + An optional comma-separated list of module search paths. + When NULL, the default search path is used. + + + + + subdirlist + + An optional NULL terminated list of + subdirectories to search. When NULL, + the default built-in list is used (refer to + stdSubdirs in loadmod.c). + The default list is also substituted for entries in + subdirlist with the value + DEFAULT_LIST. This makes is possible + to augment the default list instead of replacing it. + Subdir elements must be relative, and must not contain + "..". If any violate this requirement, + the load fails. + + + + + patternlist + + An optional NULL terminated list of + POSIX regular expressions used to connect module + filenames with canonical module names. Each regex + should contain exactly one subexpression that corresponds + to the canonical module name. When NULL, + the default built-in list is used (refer to + stdPatterns in + loadmod.c). The default list is also + substituted for entries in patternlist + with the value DEFAULT_LIST. This + makes it possible to augment the default list instead + of replacing it. + + + + + options + + An optional parameter that is passed to the newly + loaded module's SetupProc function + (if it has one). This argument is normally a + NULL terminated list of + Options, and must be interpreted that + way by modules loaded directly by the XFree86 common + layer. However, it may be used for application-specific + parameter passing in other situations. + + + + When loading external modules (modules that don't + have the standard entry point, for example a + special shared library) the options parameter can be + set to EXTERN_MODULE to tell the + loader not to reject the module when it doesn't find + the standard entry point. + + + + + modreq + + An optional XF86ModReqInfo* containing + version/ABI/vendor information to requirements to + check the newly loaded module against. The main + purpose of this is to allow the loader to verify that + a module of the correct type/version before running + its SetupProc function. + + + + The XF86ModReqInfo struct is defined + as follows: + +typedef struct { + CARD8 majorversion; /* MAJOR_UNSPEC */ + CARD8 minorversion; /* MINOR_UNSPEC */ + CARD16 patchlevel; /* PATCH_UNSPEC */ + const char * abiclass; /* ABI_CLASS_NONE */ + CARD32 abiversion; /* ABI_VERS_UNSPEC */ + const char * moduleclass; /* MOD_CLASS_NONE */ +} XF86ModReqInfo; + + + The information here is compared against the equivalent + information in the module's + XF86ModuleVersionInfo record (which + is described below). The values in comments above + indicate don't care settings for each of the fields. + The comparisons made are as follows: + + + + majorversion + + Must match the module's majorversion + exactly. + + + + minorversion + + The module's minor version must be + no less than this value. This + comparison is only made if + majorversion is + specified and matches. + + + + patchlevel + + The module's patchlevel must be no + less than this value. This comparison + is only made if + minorversion is + specified and matches. + + + + abiclass + + String must match the module's abiclass + string. + + + + abiversion + + Must be consistent with the module's + abiversion (major equal, minor no + older). + + + + moduleclass + + String must match the module's + moduleclass string. + + + + + + + errmaj + + An optional pointer to a variable holding the major + part or the error code. When provided, + *errmaj is filled in when + LoadModule() fails. + + + + errmin + + Like errmaj, but for the minor part + of the error code. + + + + +
+
+ +
+ + void UnloadModule(pointer mod); + +
+ This function unloads the module referred to by the handle mod. + All child modules are also unloaded recursively. This function must + not be used to directly unload modules that are child modules (i.e., + those that have been loaded with the LoadSubModule() + described below). + + +
+ + + + Module Requirements + + +Modules must provide information about themselves to the loader, and +may optionally provide entry points for "setup" and "teardown" functions +(those two functions are referred to here as SetupProc +and TearDownProc). + + + +The module information is contained in the +XF86ModuleVersionInfo struct, which is defined as follows: + + +typedef struct { + const char * modname; /* name of module, e.g. "foo" */ + const char * vendor; /* vendor specific string */ + CARD32 _modinfo1_; /* constant MODINFOSTRING1/2 to find */ + CARD32 _modinfo2_; /* infoarea with a binary editor/sign tool */ + CARD32 xf86version; /* contains XF86_VERSION_CURRENT */ + CARD8 majorversion; /* module-specific major version */ + CARD8 minorversion; /* module-specific minor version */ + CARD16 patchlevel; /* module-specific patch level */ + const char * abiclass; /* ABI class that the module uses */ + CARD32 abiversion; /* ABI version */ + const char * moduleclass; /* module class */ + CARD32 checksum[4]; /* contains a digital signature of the */ + /* version info structure */ +} XF86ModuleVersionInfo; + + +The fields are used as follows: + + + + modname + + The module's name. This field is currently only for + informational purposes, but the loader may be modified + in future to require it to match the module's canonical + name. + + + + + vendor + + The module vendor. This field is for informational purposes + only. + + + + + _modinfo1_ + + This field holds the first part of a signature that can + be used to locate this structure in the binary. It should + always be initialised to MODINFOSTRING1. + + + + + _modinfo2_ + + This field holds the second part of a signature that can + be used to locate this structure in the binary. It should + always be initialised to MODINFOSTRING2. + + + + + xf86version + + The XFree86 version against which the module was compiled. + This is mostly for informational/diagnostic purposes. It + should be initialised to XF86_VERSION_CURRENT, which is + defined in xf86Version.h. + + + + + majorversion + + The module-specific major version. For modules where this + version is used for more than simply informational + purposes, the major version should only change (be + incremented) when ABI incompatibilities are introduced, + or ABI components are removed. + + + + + minorversion + + The module-specific minor version. For modules where this + version is used for more than simply informational + purposes, the minor version should only change (be + incremented) when ABI additions are made in a backward + compatible way. It should be reset to zero when the major + version is increased. + + + + + patchlevel + + The module-specific patch level. The patch level should + increase with new revisions of the module where there + are no ABI changes, and it should be reset to zero when + the minor version is increased. + + + + + abiclass + + The ABI class that the module requires. The class is + specified as a string for easy extensibility. It should + indicate which (if any) of the X server's built-in ABI + classes that the module relies on, or a third-party ABI + if appropriate. Built-in ABI classes currently defined are: + + + + ABI_CLASS_NONE + no class + + + ABI_CLASS_ANSIC + only requires the ANSI C interfaces + + + ABI_CLASS_VIDEODRV + requires the video driver ABI + + + ABI_CLASS_XINPUT + requires the XInput driver ABI + + + ABI_CLASS_EXTENSION + requires the extension module ABI + + + ABI_CLASS_FONT + requires the font module ABI + + + + + + + abiversion + + The version of abiclass that the module requires. The + version consists of major and minor components. The + major version must match and the minor version must be + no newer than that provided by the server or parent + module. Version identifiers for the built-in classes + currently defined are: + + + ABI_ANSIC_VERSION + ABI_VIDEODRV_VERSION + ABI_XINPUT_VERSION + ABI_EXTENSION_VERSION + ABI_FONT_VERSION + + + + + + moduleclass + + This is similar to the abiclass field, except that it + defines the type of module rather than the ABI it + requires. For example, although all video drivers require + the video driver ABI, not all modules that require the + video driver ABI are video drivers. This distinction + can be made with the moduleclass. Currently pre-defined + module classes are: + + + MOD_CLASS_NONE + MOD_CLASS_VIDEODRV + MOD_CLASS_XINPUT + MOD_CLASS_FONT + MOD_CLASS_EXTENSION + + + + + + checksum + + Not currently used. + + + + + + +The module version information, and the optional SetupProc +and TearDownProc entry points are found by the loader +by locating a data object in the module called "modnameModuleData", +where "modname" is the canonical name of the module. Modules must +contain such a data object, and it must be declared with global scope, +be compile-time initialised, and is of the following type: + + +typedef struct { + XF86ModuleVersionInfo * vers; + ModuleSetupProc setup; + ModuleTearDownProc teardown; +} XF86ModuleData; + + + + +The vers parameter must be initialised to a pointer to a correctly +initialised XF86ModuleVersionInfo struct. The other +two parameter are optional, and should be initialised to +NULL when not required. The other parameters are defined +as + +
+ + typedef pointer (*ModuleSetupProc)(pointer, pointer, int *, int *); + + typedef void (*ModuleTearDownProc)(pointer); + + pointer SetupProc(pointer module, pointer options, + int *errmaj, int *errmin); + +
+ When defined, this function is called by the loader after successfully + loading a module. module is a handle for the newly loaded module, + and maybe used by the SetupProc if it calls other + loader functions that require a reference to it. The remaining + arguments are those that were passed to the + LoadModule() (or LoadSubModule()), + and are described above. When the SetupProc is + successful it must return a non-NULL value. The + loader checks this, and if it is NULL it unloads + the module and reports the failure to the caller of + LoadModule(). If the SetupProc + does things that need to be undone when the module is unloaded, + it should define a TearDownProc, and return a + pointer that the TearDownProc can use to undo what + has been done. + + + + When a module is loaded multiple times, the SetupProc + is called once for each time it is loaded. + + +
+ +
+ + void TearDownProc(pointer tearDownData); + +
+ When defined, this function is called when the loader unloads a + module. The tearDownData parameter is the return + value of the SetupProc() that was called when the + module was loaded. The purpose of this function is to clean up + before the module is unloaded (for example, by freeing allocated + resources). + + +
+ + + + + Public Loader Interface + + +The following is the Loader interface that is available to any part of +the server, and may also be used from within modules. + + +
+ + pointer LoadSubModule(pointer parent, const char *module, + const char **subdirlist, const char **patternlist, + pointer options, const XF86ModReqInfo * modreq, + int *errmaj, int *errmin); + +
+ This function is like the LoadModule() function + described above, except that the module loaded is registered as a + child of the calling module. The parent parameter + is the calling module's handle. Modules loaded with this function + are automatically unloaded when the parent module is unloaded. The + other difference is that the path parameter may not be specified. + The module search path used for modules loaded with this function + is the default search path as initialised with + LoaderSetPath(). + + +
+ +
+ + void UnloadSubModule(pointer module); + +
+ This function unloads the module with handle module. + If that module itself has children, they are also unloaded. It is + like UnloadModule(), except that it is safe to use + for unloading child modules. + + +
+ +
+ + pointer LoaderSymbol(const char *symbol); + +
+ This function returns the address of the symbol with name + symbol. This may be used to locate a module entry + point with a known name. + + +
+ +
+ + char **LoaderlistDirs(const char **subdirlist, + const char **patternlist); + +
+ This function returns a NULL terminated list of + canonical modules names for modules found in the default module + search path. The subdirlist and + patternlist parameters are as described above, and + can be used to control the locations and names that are searched. + If no modules are found, the return value is NULL. + The returned list should be freed by calling + LoaderFreeDirList() when it is no longer needed. + + +
+ +
+ + void LoaderFreeDirList(char **list); + +
+ This function frees a module list created by + LoaderlistDirs(). + + +
+ +
+ + void LoaderReqSymLists(const char **list0, ...); + +
+ This function allows the registration of required symbols with the + loader. It is normally used by a caller of + LoadSubModule(). If any symbols registered in this + way are found to be unresolved when + LoaderCheckUnresolved() is called then + LoaderCheckUnresolved() will report a failure. + The function takes one or more NULL terminated + lists of symbols. The end of the argument list is indicated by a + NULL argument. + + +
+ +
+ + void LoaderReqSymbols(const char *sym0, ...); + +
+ This function is like LoaderReqSymLists() except + that its arguments are symbols rather than lists of symbols. This + function is more convenient when single functions are to be registered, + especially when the single function might depend on runtime factors. + The end of the argument list is indicated by a NULL + argument. + + +
+ +
+ + void LoaderRefSymLists(const char **list0, ...); + +
+ This function allows the registration of possibly unresolved symbols + with the loader. When LoaderCheckUnresolved() is + run it won't generate warnings for symbols registered in this way + unless they were also registered as required symbols. + The function takes one or more NULL terminated + lists of symbols. The end of the argument list is indicated by a + NULL argument. + + +
+ +
+ + void LoaderRefSymbols(const char *sym0, ...); + +
+ This function is like LoaderRefSymLists() except + that its arguments are symbols rather than lists of symbols. This + function is more convenient when single functions are to be registered, + especially when the single function might depend on runtime factors. + The end of the argument list is indicated by a NULL + argument. + + +
+ +
+ + int LoaderCheckUnresolved(int delayflag); + +
+ This function checks for unresolved symbols. It generates warnings + for unresolved symbols that have not been registered with + LoaderRefSymLists(), and maps them to a dummy + function. This behaviour may change in future. If unresolved + symbols are found that have been registered with + LoaderReqSymLists() or + LoaderReqSymbols() then this function returns a + non-zero value. If none of these symbols are unresolved the return + value is zero, indicating success. + + + + The delayflag parameter should normally be set to + LD_RESOLV_IFDONE. + + +
+ +
+ + LoaderErrorMsg(const char *name, const char *modname, + int errmaj, int errmin); + +
+ This function prints an error message that includes the text Failed + to load module, the module name modname, a message + specific to the errmaj value, and the value if + errmin. If name is + non-NULL, it is printed as an identifying prefix + to the message (followed by a :). + + +
+ + + + Special Registration Functions + + +The loader contains some functions for registering some classes of modules. +These may be moved out of the loader at some point. + + +
+ + void LoadExtension(ExtensionModule *ext); + +
+ This registers the entry points for the extension identified by + ext. The ExtensionModule struct is + defined as: + + +typedef struct { + InitExtension initFunc; + char * name; + Bool *disablePtr; + InitExtension setupFunc; +} ExtensionModule; + + + +
+ +
+ + void LoadFont(FontModule *font); + +
+ This registers the entry points for the font rasteriser module + identified by font. The FontModule + struct is defined as: + + + typedef struct { + InitFont initFunc; + char * name; + pointer module; +} FontModule; + + + +
+ + + + + + + Helper Functions + + +This section describe helper functions that video driver +might find useful. While video drivers are not required to use any of +these to be considered compliant, the use of appropriate helpers is +strongly encouraged to improve the consistency of driver behaviour. + + + + Functions for printing messages + +
+ + ErrorF(const char *format, ...); + +
+ This is the basic function for writing to the error log (typically + stderr and/or a log file). Video drivers should usually avoid + using this directly in favour of the more specialised functions + described below. This function is useful for printing messages + while debugging a driver. + + +
+ +
+ + FatalError(const char *format, ...); + +
+ This prints a message and causes the Xserver to abort. It should + rarely be used within a video driver, as most error conditions + should be flagged by the return values of the driver functions. + This allows the higher layers to decide how to proceed. In rare + cases, this can be used within a driver if a fatal unexpected + condition is found. + + +
+ +
+ + xf86ErrorF(const char *format, ...); + +
+ This is like ErrorF(), except that the message is + only printed when the Xserver's verbosity level is set to the + default (1) or higher. It means that the messages + are not printed when the server is started with the + flag. Typically this function would only be + used for continuing messages started with one of the more specialised + functions described below. + + +
+ +
+ + xf86ErrorFVerb(int verb, const char *format, ...); + +
+ Like xf86ErrorF(), except the minimum verbosity + level for which the message is to be printed is given explicitly. + Passing a verb value of zero means the message + is always printed. A value higher than 1 can be + used for information would normally not be needed, but which might + be useful when diagnosing problems. + + +
+ + +
+ + xf86Msg(MessageType type, const char *format, ...); + +
+ This is like xf86ErrorF(), except that the message + is prefixed with a marker determined by the value of + type. The marker is used to indicate the type of + message (warning, error, probed value, config value, etc). Note + the xf86Verbose value is ignored for messages of + type X_ERROR. + + + + The marker values are: + + + + X_PROBED + Value was probed. + + + X_CONFIG + Value was given in the config file. + + + X_DEFAULT + Value is a default. + + + X_CMDLINE + Value was given on the command line. + + + X_NOTICE + Notice. + + + X_ERROR + Error message. + + + X_WARNING + Warning message. + + + X_INFO + Informational message. + + + X_NONE + No prefix. + + + X_NOT_IMPLEMENTED + The message relates to functionality + that is not yetimplemented. + + + + + +
+ +
+ + xf86MsgVerb(MessageType type, int verb, const char *format, ...); + +
+ Like xf86Msg(), but with the verbosity level given + explicitly. + + +
+ +
+ + xf86DrvMsg(int scrnIndex, MessageType type, const char *format, ...); + +
+ This is like xf86Msg() except that the driver's + name (the name field of the + ScrnInfoRec) followed by the + scrnIndex in parentheses is printed following the + prefix. This should be used by video drivers in most cases as it + clearly indicates which driver/screen the message is for. If + scrnIndex is negative, this function behaves + exactly like xf86Msg(). + + + + NOTE: This function can only be used after the + ScrnInfoRec and its name field + have been allocated. Normally, this means that it can not be + used before the END of the ChipProbe() function. + Prior to that, use xf86Msg(), providing the + driver's name explicitly. No screen number can be supplied at + that point. + + +
+ +
+ + xf86DrvMsgVerb(int scrnIndex, MessageType type, int verb, + const char *format, ...); + +
+ Like xf86DrvMsg(), but with the verbosity level + given explicitly. + + +
+ + + + + Functions for setting values based on command line and config file + +
+ + Bool xf86SetDepthBpp(ScrnInfoPtr scrp, int depth, int bpp, + + int fbbpp, int depth24flags); + +
+ This function sets the depth, pixmapBPP and bitsPerPixel fields + of the ScrnInfoRec. It also determines the defaults for display-wide + attributes and pixmap formats the screen will support, and finds + the Display subsection that matches the depth/bpp. This function + should normally be called very early from the + ChipPreInit() function. + + + + It requires that the confScreen field of the ScrnInfoRec be + initialised prior to calling it. This is done by the XFree86 + common layer prior to calling ChipPreInit(). + + + + The parameters passed are: + + + + depth + + driver's preferred default depth if no other is given. + If zero, use the overall server default. + + + + bpp + + Same, but for the pixmap bpp. + + + + fbbpp + + Same, but for the framebuffer bpp. + + + + depth24flags + + Flags that indicate the level of 24/32bpp support + and whether conversion between different framebuffer + and pixmap formats is supported. The flags for this + argument are defined as follows, and multiple flags + may be ORed together: + + + + NoDepth24Support + No depth 24 formats supported + + + Support24bppFb + 24bpp framebuffer supported + + + Support32bppFb + 32bpp framebuffer supported + + + SupportConvert24to32 + Can convert 24bpp pixmap to 32bpp fb + + + SupportConvert32to24 + Can convert 32bpp pixmap to 24bpp fb + + + ForceConvert24to32 + Force 24bpp pixmap to 32bpp fb conversion + + + ForceConvert32to24 + Force 32bpp pixmap to 24bpp fb conversion + + + + + + + + + It uses the command line, config file, and default values in the + correct order of precedence to determine the depth and bpp values. + It is up to the driver to check the results to see that it supports + them. If not the ChipPreInit() function should + return FALSE. + + + + If only one of depth/bpp is given, the other is set to a reasonable + (and consistent) default. + + + + If a driver finds that the initial depth24flags + it uses later results in a fb format that requires more video + memory than is available it may call this function a second time + with a different depth24flags setting. + + + + On success, the return value is TRUE. On failure + it prints an error message and returns FALSE. + + + + The following fields of the ScrnInfoRec are + initialised by this function: + +
+depth, bitsPerPixel, +display, imageByteOrder, +bitmapScanlinePad, +bitmapScanlineUnit, bitmapBitOrder, +numFormats, formats, +fbFormat. +
+ + +
+ +
+ + void xf86PrintDepthBpp(scrnInfoPtr scrp); + +
+ This function can be used to print out the depth and bpp settings. + It should be called after the final call to + xf86SetDepthBpp(). + + +
+ +
+ + Bool xf86SetWeight(ScrnInfoPtr scrp, rgb weight, rgb mask); + +
+ This function sets the weight, mask, + offset and rgbBits fields of the + ScrnInfoRec. It would normally be called fairly + early in the ChipPreInit() function for + depths > 8bpp. + + + + It requires that the depth and + display fields of the ScrnInfoRec + be initialised prior to calling it. + + + + The parameters passed are: + + + + weight + + driver's preferred default weight if no other is given. + If zero, use the overall server default. + + + + + mask + + Same, but for mask. + + + + + + + It uses the command line, config file, and default values in the + correct order of precedence to determine the weight value. It + derives the mask and offset values from the weight and the defaults. + It is up to the driver to check the results to see that it supports + them. If not the ChipPreInit() function should + return FALSE. + + + + On success, this function prints a message showing the weight + values selected, and returns TRUE. + + + + On failure it prints an error message and returns FALSE. + + + + The following fields of the ScrnInfoRec are + initialised by this function: + +
+ weight, + mask, + offset. +
+ + +
+ +
+ + Bool xf86SetDefaultVisual(ScrnInfoPtr scrp, int visual); + +
+ This function sets the defaultVisual field of the + ScrnInfoRec. It would normally be called fairly + early from the ChipPreInit() function. + + + + It requires that the depth and + display fields of the ScrnInfoRec + be initialised prior to calling it. + + + + The parameters passed are: + + + + visual + + driver's preferred default visual if no other is given. + If -1, use the overall server default. + + + + + + + It uses the command line, config file, and default values in the + correct order of precedence to determine the default visual value. + It is up to the driver to check the result to see that it supports + it. If not the ChipPreInit() function should + return FALSE. + + + + On success, this function prints a message showing the default visual + selected, and returns TRUE. + + + + On failure it prints an error message and returns FALSE. + + +
+ +
+ + Bool xf86SetGamma(ScrnInfoPtr scrp, Gamma gamma); + +
+ This function sets the gamma field of the + ScrnInfoRec. It would normally be called fairly + early from the ChipPreInit() function in cases + where the driver supports gamma correction. + + + + It requires that the monitor field of the + ScrnInfoRec be initialised prior to calling it. + + + + The parameters passed are: + + + + gamma + + driver's preferred default gamma if no other is given. + If zero (< 0.01), use the overall server + default. + + + + + + + It uses the command line, config file, and default values in the + correct order of precedence to determine the gamma value. It is + up to the driver to check the results to see that it supports + them. If not the ChipPreInit() function should + return FALSE. + + + + On success, this function prints a message showing the gamma + value selected, and returns TRUE. + + + + On failure it prints an error message and returns FALSE. + + +
+ + +
+ + void xf86SetDpi(ScrnInfoPtr pScrn, int x, int y); + +
+ This function sets the xDpi and yDpi + fields of the ScrnInfoRec. The driver can specify + preferred defaults by setting x and y + to non-zero values. The command line option + overrides all other settings. Otherwise, if the + DisplaySize entry is present in the screen's &k.monitor; + config file section, it is used together with the virtual size to + calculate the dpi values. This function should be called after + all the mode resolution has been done. + + +
+ +
+ + void xf86SetBlackWhitePixels(ScrnInfoPtr pScrn); + +
+ This functions sets the blackPixel and + whitePixel fields of the ScrnInfoRec + according to whether or not the command + line options is present. + + +
+ +
+ + const char *xf86GetVisualName(int visual); + +
+ Returns a printable string with the visual name matching the + numerical visual class provided. If the value is outside the + range of valid visual classes, NULL is returned. + + +
+ + + + + Primary Mode functions + + +The primary mode helper functions are those which would normally be +used by a driver, unless it has unusual requirements which cannot +be catered for the by the helpers. + + +
+ + int xf86ValidateModes(ScrnInfoPtr scrp, DisplayModePtr availModes, + char **modeNames, ClockRangePtr clockRanges, + int *linePitches, int minPitch, int maxPitch, + int pitchInc, int minHeight, int maxHeight, + int virtualX, int virtualY, + unsigned long apertureSize, + LookupModeFlags strategy); + +
+ This function basically selects the set of modes to use based on + those available and the various constraints. It also sets some + other related parameters. It is normally called near the end of + the ChipPreInit() function. + + + + The parameters passed to the function are: + + + + availModes + + List of modes available for the monitor. + + + + modeNames + + List of mode names that the screen is requesting. + + + + clockRanges + + A list of clock ranges allowed by the driver. Each + range includes whether interlaced or multiscan modes + are supported for that range. See below for more on + clockRanges. + + + + linePitches + + List of line pitches supported by the driver. + This is optional and should be NULL when + not used. + + + + minPitch + + Minimum line pitch supported by the driver. This must + be supplied when linePitches is + NULL, and is ignored otherwise. + + + + maxPitch + + Maximum line pitch supported by the driver. This is + required when minPitch is required. + + + + pitchInc + + Granularity of horizontal pitch values as supported by + the chipset. This is expressed in bits. This must be + supplied. + + + + minHeight + + minimum virtual height allowed. If zero, no limit is + imposed. + + + + maxHeight + + maximum virtual height allowed. If zero, no limit is + imposed. + + + + virtualX + + If greater than zero, this is the virtual width value + that will be used. Otherwise, the virtual width is + chosen to be the smallest that can accommodate the modes + selected. + + + + virtualY + + If greater than zero, this is the virtual height value + that will be used. Otherwise, the virtual height is + chosen to be the smallest that can accommodate the modes + selected. + + + + apertureSize + + The size (in bytes) of the aperture used to access video + memory. + + + + strategy + + The strategy to use when choosing from multiple modes + with the same name. The options are: + + + + LOOKUP_DEFAULT + ??? + + + LOOKUP_BEST_REFRESH + mode with best refresh rate + + + LOOKUP_CLOSEST_CLOCK + mode with closest matching clock + + + LOOKUP_LIST_ORDER + first usable mode in list + + + + The following options can also be combined (OR'ed) with + one of the above: + + + + LOOKUP_CLKDIV2 + Allow halved clocks + + + LOOKUP_OPTIONAL_TOLERANCES + + Allow missing horizontal sync and/or vertical refresh + ranges in the xorg.conf Monitor section + + + + LOOKUP_OPTIONAL_TOLERANCES should only be + specified when the driver can ensure all modes it generates + can sync on, or at least not damage, the monitor or digital + flat panel. Horizontal sync and/or vertical refresh ranges + specified by the user will still be honoured (and acted upon). + + + + + + + This function requires that the following fields of the + ScrnInfoRec are initialised prior to calling it: + + + + clock[] + + List of discrete clocks (when non-programmable) + + + numClocks + + Number of discrete clocks (when non-programmable) + + + progClock + + Whether the clock is programmable or not + + + monitor + + Pointer to the applicable xorg.conf monitor section + + + fdFormat + + Format of the screen buffer + + + videoRam + + total video memory size (in bytes) + + + maxHValue + + Maximum horizontal timing value allowed + + + maxVValue + + Maximum vertical timing value allowed + + + xInc + + Horizontal timing increment in pixels (defaults to 8) + + + + + + This function fills in the following ScrnInfoRec + fields: + + + + modePool + + A subset of the modes available to the monitor which + are compatible with the driver. + + + + modes + + One mode entry for each of the requested modes, with + the status field of each filled in to indicate if + the mode has been accepted or not. This list of + modes is a circular list. + + + + virtualX + + The resulting virtual width. + + + + virtualY + + The resulting virtual height. + + + + displayWidth + + The resulting line pitch. + + + + virtualFrom + + Where the virtual size was determined from. + + + + + + + The first stage of this function checks that the + virtualX and virtualY values + supplied (if greater than zero) are consistent with the line pitch + and maxHeight limitations. If not, an error + message is printed, and the return value is -1. + + + + The second stage sets up the mode pool, eliminating immediately + any modes that exceed the driver's line pitch limits, and also + the virtual width and height limits (if greater than zero). For + each mode removed an informational message is printed at verbosity + level 2. If the mode pool ends up being empty, + a warning message is printed, and the return value is + 0. + + + + The final stage is to lookup each mode name, and fill in the remaining + parameters. If an error condition is encountered, a message is + printed, and the return value is -1. Otherwise, + the return value is the number of valid modes found + (0 if none are found). + + + + Even if the supplied mode names include duplicates, no two names will + ever match the same mode. Furthermore, if the supplied mode names do not + yield a valid mode (including the case where no names are passed at all), + the function will continue looking through the mode pool until it finds + a mode that survives all checks, or until the mode pool is exhausted. + + + + A message is only printed by this function when a fundamental + problem is found. It is intended that this function may be called + more than once if there is more than one set of constraints that + the driver can work within. + + + + If this function returns -1, the + ChipPreInit() function should return + FALSE. + + + + clockRanges is a linked list of clock ranges + allowed by the driver. If a mode doesn't fit in any of the defined + clockRanges, it is rejected. The first + clockRange that matches all requirements is used. + This structure needs to be initialized to NULL when allocated. + + + + clockRanges contains the following fields: + + + + minClock + maxClock + + The lower and upper mode clock bounds for which the rest + of the clockRange parameters apply. + Since these are the mode clocks, they are not scaled + with the ClockMulFactor and + ClockDivFactor. It is up to the driver + to adjust these values if they depend on the clock + scaling factors. + + + + clockIndex + + (not used yet) -1 for programmable clocks + + + + interlaceAllowed + + TRUE if interlacing is allowed for this + range + + + + doubleScanAllowed + + TRUE if doublescan or multiscan is allowed + for this range + + + + ClockMulFactor + ClockDivFactor + + Scaling factors that are applied to the mode clocks ONLY + before selecting a clock index (when there is no + programmable clock) or a SynthClock + value. This is useful for drivers that support pixel + multiplexing or that need to scale the clocks because + of hardware restrictions (like sending 24bpp data to an + 8 bit RAMDAC using a tripled clock). + + + + Note that these parameters describe what must be done + to the mode clock to achieve the data transport clock + between graphics controller and RAMDAC. For example + for 2:1 pixel multiplexing, two pixels + are sent to the RAMDAC on each clock. This allows the + RAMDAC clock to be half of the actual pixel clock. + Hence, ClockMulFactor=1 and + ClockDivFactor=2. This means that the + clock used for clock selection (ie, determining the + correct clock index from the list of discrete clocks) + or for the SynthClock field in case of + a programmable clock is: (mode->Clock * + ClockMulFactor) / ClockDivFactor. + + + + PrivFlags + + This field is copied into the + mode->PrivFlags field when this + clockRange is selected by + xf86ValidateModes(). It allows the + driver to find out what clock range was selected, so it + knows it needs to set up pixel multiplexing or any other + range-dependent feature. This field is purely + driver-defined: it may contain flag bits, an index or + anything else (as long as it is an INT). + + + + + + Note that the mode->SynthClock field is always + filled in by xf86ValidateModes(): it will contain + the data transport clock, which is the clock that will have + to be programmed in the chip when it has a programmable clock, or + the clock that will be picked from the clocks list when it is not + a programmable one. Thus: + + + mode->SynthClock = (mode->Clock * ClockMulFactor) / ClockDivFactor + + + +
+ +
+ + void xf86PruneDriverModes(ScrnInfoPtr scrp); + +
+ This function deletes modes in the modes field of the + ScrnInfoRec that have been marked as invalid. + This is normally run after having run + xf86ValidateModes() for the last time. For each + mode that is deleted, a warning message is printed out indicating + the reason for it being deleted. + + +
+ +
+ + void xf86SetCrtcForModes(ScrnInfoPtr scrp, int adjustFlags); + +
+ This function fills in the Crtc* fields for all + the modes in the modes field of the + ScrnInfoRec. The adjustFlags + parameter determines how the vertical CRTC values are scaled for + interlaced modes. They are halved if it is + INTERLACE_HALVE_V. The vertical CRTC values are + doubled for doublescan modes, and are further multiplied by the + VScan value. + + + + This function is normally called after calling + xf86PruneDriverModes(). + + +
+ +
+ + void xf86PrintModes(ScrnInfoPtr scrp); + +
+ This function prints out the virtual size setting, and the line + pitch being used. It also prints out two lines for each mode being + used. The first line includes the mode's pixel clock, horizontal sync + rate, refresh rate, and whether it is interlaced, doublescanned and/or + multi-scanned. The second line is the mode's Modeline. + + + + This function is normally called after calling + xf86SetCrtcForModes(). + + +
+ + + + + Secondary Mode functions + + +The secondary mode helper functions are functions which are normally +used by the primary mode helper functions, and which are not normally +called directly by a driver. If a driver has unusual requirements +and needs to do its own mode validation, it might be able to make +use of some of these secondary mode helper functions. + + +
+ + int xf86GetNearestClock(ScrnInfoPtr scrp, int freq, Bool allowDiv2, + int *divider); + +
+ This function returns the index of the closest clock to the + frequency freq given (in kHz). It assumes that + the number of clocks is greater than zero. It requires that the + numClocks and clock fields of the + ScrnInfoRec are initialised. The + allowDiv2 field determines if the clocks can be + halved. The *divider return value indicates + whether clock division is used when determining the clock returned. + + + + This function is only for non-programmable clocks. + + +
+ +
+ + const char *xf86ModeStatusToString(ModeStatus status); + +
+ This function converts the status value to a + descriptive printable string. + + +
+ +
+ + ModeStatus xf86LookupMode(ScrnInfoPtr scrp, DisplayModePtr modep, + ClockRangePtr clockRanges, LookupModeFlags strategy); + +
+ This function takes a pointer to a mode with the name filled in, + and looks for a mode in the modePool list which + matches. The parameters of the matching mode are filled in to + *modep. The clockRanges and + strategy parameters are as for the + xf86ValidateModes() function above. + + + + This function requires the modePool, + clock[], numClocks and + progClock fields of the ScrnInfoRec + to be initialised before being called. + + + + The return value is MODE_OK if a mode was found. + Otherwise it indicates why a matching mode could not be found. + + +
+ +
+ + ModeStatus xf86InitialCheckModeForDriver(ScrnInfoPtr scrp, + DisplayModePtr mode, ClockRangePtr clockRanges, + LookupModeFlags strategy, int maxPitch, + int virtualX, int virtualY); + +
+ This function checks the passed mode against some basic driver + constraints. Apart from the ones passed explicitly, the + maxHValue and maxVValue fields of + the ScrnInfoRec are also used. If the + ValidMode field of the ScrnInfoRec + is set, that function is also called to check the mode. Next, the + mode is checked against the monitor's constraints. + + + + If the mode is consistent with all constraints, the return value + is MODE_OK. Otherwise the return value indicates + which constraint wasn't met. + + +
+ +
+ + void xf86DeleteMode(DisplayModePtr *modeList, DisplayModePtr mode); + +
+ This function deletes the mode given from the + modeList. It never prints any messages, so it is + up to the caller to print a message if required. + + +
+ + + + Functions for handling strings and tokens + + + Tables associating strings and numerical tokens combined with the + following functions provide a compact way of handling strings from + the config file, and for converting tokens into printable strings. + The table data structure is: + + +typedef struct { + int token; + const char * name; +} SymTabRec, *SymTabPtr; + + + + + A table is an initialised array of SymTabRec. The + tokens must be non-negative integers. Multiple names may be mapped + to a single token. The table is terminated with an element with a + token value of -1 and + NULL for the name. + + +
+ + const char *xf86TokenToString(SymTabPtr table, int token); + +
+ This function returns the first string in table + that matches token. If no match is found, + NULL is returned (NOTE, older versions of this + function would return the string "unknown" when no match is found). + + +
+ +
+ + int xf86StringToToken(SymTabPtr table, const char *string); + +
+ This function returns the first token in table + that matches string. The + xf86NameCmp() function is used to determine the + match. If no match is found, -1 is returned. + + +
+ + + + + Functions for finding which config file entries to use + + + These functions can be used to select the appropriate config file + entries that match the detected hardware. They are described above + in the Probe and + Available Functions sections. + + + + + + Probing discrete clocks on old hardware + + + The xf86GetClocks() function may be used to assist + in finding the discrete pixel clock values on older hardware. + + +
+ + void xf86GetClocks(ScrnInfoPtr pScrn, int num, + Bool (*ClockFunc)(ScrnInfoPtr, int), + void (*ProtectRegs)(ScrnInfoPtr, Bool), + void (*BlankScreen)(ScrnInfoPtr, Bool), + int vertsyncreg, int maskval, int knownclkindex, + int knownclkvalue); + +
+ This function uses a comparative sampling method to measure the + discrete pixel clock values. The number of discrete clocks to + measure is given by num. clockFunc + is a function that selects the n'th clock. It + should also save or restore any state affected by programming the + clocks when the index passed is CLK_REG_SAVE or + CLK_REG_RESTORE. ProtectRegs is + a function that does whatever is required to protect the hardware + state while selecting a new clock. BlankScreen + is a function that blanks the screen. vertsyncreg + and maskval are the register and bitmask to + check for the presence of vertical sync pulses. + knownclkindex and knownclkvalue + are the index and value of a known clock. These are the known + references on which the comparative measurements are based. The + number of clocks probed is set in pScrn->numClocks, + and the probed clocks are set in the pScrn->clock[] + array. All of the clock values are in units of kHz. + + +
+ +
+ + void xf86ShowClocks(ScrnInfoPtr scrp, MessageType from); + +
+ Print out the pixel clocks scrp->clock[]. + from indicates whether the clocks were probed + or from the config file. + + +
+ + + + Other helper functions + +
+ + Bool xf86IsUnblank(int mode); + +
+ Returns TRUE when the screen saver mode specified + by mode requires the screen be unblanked, + and FALSE otherwise. The screen saver modes that + require blanking are SCREEN_SAVER_ON and + SCREEN_SAVER_CYCLE, and the screen saver modes that + require unblanking are SCREEN_SAVER_OFF and + SCREEN_SAVER_FORCER. Drivers may call this helper + from their SaveScreen() function to interpret the + screen saver modes. + + +
+ + + + + The vgahw module + + +The vgahw modules provides an interface for saving, restoring and +programming the standard VGA registers, and for handling VGA colourmaps. + + + + Data Structures + + + The public data structures used by the vgahw module are + vgaRegRec and vgaHWRec. They are + defined in vgaHW.h. + + + + + + General vgahw Functions + +
+ + Bool vgaHWGetHWRec(ScrnInfoPtr pScrn); + +
+ This function allocates a vgaHWRec structure, and + hooks it into the ScrnInfoRec's + privates. Like all information hooked into the + privates, it is persistent, and only needs to be + allocated once per screen. This function should normally be called + from the driver's ChipPreInit() function. The + vgaHWRec is zero-allocated, and the following + fields are explicitly initialised: + + + + ModeReg.DAC[] + initialised with a default colourmap + + + ModeReg.Attribute[0x11] + initialised with the default overscan index + + + ShowOverscan + initialised according to the "ShowOverscan" option + + + paletteEnabled + initialised to FALSE + + + cmapSaved + initialised to FALSE + + + pScrn + initialised to pScrn + + + + + + In addition to the above, vgaHWSetStdFuncs() is + called to initialise the register access function fields with the + standard VGA set of functions. + + + + Once allocated, a pointer to the vgaHWRec can be + obtained from the ScrnInfoPtr with the + VGAHWPTR(pScrn) macro. + + +
+ +
+ + void vgaHWFreeHWRec(ScrnInfoPtr pScrn); + +
+ This function frees a vgaHWRec structure. It + should be called from a driver's ChipFreeScreen() + function. + + +
+ +
+ + Bool vgaHWSetRegCounts(ScrnInfoPtr pScrn, int numCRTC, + int numSequencer, int numGraphics, int numAttribute); + +
+ This function allows the number of CRTC, Sequencer, Graphics and + Attribute registers to be changed. This makes it possible for + extended registers to be saved and restored with + vgaHWSave() and vgaHWRestore(). + This function should be called after a vgaHWRec + has been allocated with vgaHWGetHWRec(). The + default values are defined in vgaHW.h as follows: + + +#define VGA_NUM_CRTC 25 +#define VGA_NUM_SEQ 5 +#define VGA_NUM_GFX 9 +#define VGA_NUM_ATTR 21 + + + +
+ +
+ + Bool vgaHWCopyReg(vgaRegPtr dst, vgaRegPtr src); + +
+ This function copies the contents of the VGA saved registers in + src to dst. Note that it isn't + possible to simply do this with memcpy() (or + similar). This function returns TRUE unless there + is a problem allocating space for the CRTC and + related fields in dst. + + +
+ +
+ + void vgaHWSetStdFuncs(vgaHWPtr hwp); + +
+ This function initialises the register access function fields of + hwp with the standard VGA set of functions. This + is called by vgaHWGetHWRec(), so there is usually + no need to call this explicitly. The register access functions + are described below. If the registers are shadowed in some other + port I/O space (for example a PCI I/O region), these functions + can be used to access the shadowed registers if + hwp->PIOOffset is initialised with + offset, calculated in such a way that when the + standard VGA I/O port value is added to it the correct offset into + the PIO area results. This value is initialised to zero in + vgaHWGetHWRec(). (Note: the PIOOffset functionality + is present in XFree86 4.1.0 and later.) + + +
+ +
+ + void vgaHWSetMmioFuncs(vgaHWPtr hwp, CARD8 *base, int offset); + +
+ This function initialised the register access function fields of + hwp with a generic MMIO set of functions. + hwp->MMIOBase is initialised with + base, which must be the virtual address that the + start of MMIO area is mapped to. hwp->MMIOOffset + is initialised with offset, which must be calculated + in such a way that when the standard VGA I/O port value is added + to it the correct offset into the MMIO area results. That means + that these functions are only suitable when the VGA I/O ports are + made available in a direct mapping to the MMIO space. If that is + not the case, the driver will need to provide its own register + access functions. The register access functions are described + below. + + +
+ +
+ + Bool vgaHWMapMem(ScrnInfoPtr pScrn); + +
+ This function maps the VGA memory window. It requires that the + vgaHWRec be allocated. If a driver requires + non-default MapPhys or MapSize + settings (the physical location and size of the VGA memory window) + then those fields of the vgaHWRec must be initialised + before calling this function. Otherwise, this function initialiases + the default values of 0xA0000 for + MapPhys and (64 * 1024) for + MapSize. This function must be called before + attempting to save or restore the VGA state. If the driver doesn't + call it explicitly, the vgaHWSave() and + vgaHWRestore() functions may call it if they need + to access the VGA memory (in which case they will also call + vgaHWUnmapMem() to unmap the VGA memory before + exiting). + + +
+ +
+ + void vgaHWUnmapMem(ScrnInfoPtr pScrn); + +
+ This function unmaps the VGA memory window. It must only be called + after the memory has been mapped. The Base field + of the vgaHWRec field is set to NULL + to indicate that the memory is no longer mapped. + + +
+ +
+ + void vgaHWGetIOBase(vgaHWPtr hwp); + +
+ This function initialises the IOBase field of the + vgaHWRec. This function must be called before + using any other functions that access the video hardware. + + + + A macro VGAHW_GET_IOBASE() is also available in + vgaHW.h that returns the I/O base, and this may + be used when the vgahw module is not loaded (for example, in the + ChipProbe() function). + + +
+ +
+ + void vgaHWUnlock(vgaHWPtr hwp); + +
+ This function unlocks the VGA CRTC[0-7] registers, + and must be called before attempting to write to those registers. + + +
+ +
+ + void vgaHWLock(vgaHWPtr hwp); + +
+ This function locks the VGA CRTC[0-7] registers. + + +
+ +
+ + void vgaHWEnable(vgaHWPtr hwp); + +
+ This function enables the VGA subsystem. (Note, this function is + present in XFree86 4.1.0 and later.). + + +
+ +
+ + void vgaHWDisable(vgaHWPtr hwp); + +
+ This function disables the VGA subsystem. (Note, this function is + present in XFree86 4.1.0 and later.). + + +
+ +
+ + void vgaHWSave(ScrnInfoPtr pScrn, vgaRegPtr save, int flags); + +
+ This function saves the VGA state. The state is written to the + vgaRegRec pointed to by save. + flags is set to one or more of the following flags + ORed together: + + + + VGA_SR_MODE + the mode setting registers are saved + + + VGA_SR_FONTS + the text mode font/text data is saved + + + VGA_SR_CMAP + the colourmap (LUT) is saved + + + VGA_SR_ALL + all of the above are saved + + + + + + The vgaHWRec and its IOBase fields + must be initialised before this function is called. If + VGA_SR_FONTS is set in flags, the + VGA memory window must be mapped. If it isn't then + vgaHWMapMem() will be called to map it, and + vgaHWUnmapMem() will be called to unmap it + afterwards. vgaHWSave() uses the three functions + below in the order vgaHWSaveColormap(), + vgaHWSaveMode(), vgaHWSaveFonts() to + carry out the different save phases. It is undecided at this + stage whether they will remain part of the vgahw module's public + interface or not. + + +
+ +
+ + void vgaHWSaveMode(ScrnInfoPtr pScrn, vgaRegPtr save); + +
+ This function saves the VGA mode registers. They are saved to + the vgaRegRec pointed to by save. + The registers saved are: + + + MiscOut + CRTC[0-0x18] + Attribute[0-0x14] + Graphics[0-8] + Sequencer[0-4] + + + + + The number of registers actually saved may be modified by a prior call + to vgaHWSetRegCounts(). + + +
+ +
+ + void vgaHWSaveFonts(ScrnInfoPtr pScrn, vgaRegPtr save); + +
+ This function saves the text mode font and text data held in the + video memory. If called while in a graphics mode, no save is + done. The VGA memory window must be mapped with + vgaHWMapMem() before to calling this function. + + + + On some platforms, one or more of the font/text plane saves may be + no-ops. This is the case when the platform's VC driver already + takes care of this. + + +
+ +
+ + void vgaHWSaveColormap(ScrnInfoPtr pScrn, vgaRegPtr save); + +
+ This function saves the VGA colourmap (LUT). Before saving it, it + attempts to verify that the colourmap is readable. In rare cases + where it isn't readable, a default colourmap is saved instead. + + +
+ +
+ + void vgaHWRestore(ScrnInfoPtr pScrn, vgaRegPtr restore, int flags); + +
+ This function programs the VGA state. The state programmed is + that contained in the vgaRegRec pointed to by + restore. flags is the same + as described above for the vgaHWSave() function. + + + + The vgaHWRec and its IOBase fields + must be initialised before this function is called. If + VGA_SR_FONTS is set in flags, the + VGA memory window must be mapped. If it isn't then + vgaHWMapMem() will be called to map it, and + vgaHWUnmapMem() will be called to unmap it + afterwards. vgaHWRestore() uses the three functions + below in the order vgaHWRestoreFonts(), + vgaHWRestoreMode(), + vgaHWRestoreColormap() to carry out the different + restore phases. It is undecided at this stage whether they will + remain part of the vgahw module's public interface or not. + + +
+ +
+ + void vgaHWRestoreMode(ScrnInfoPtr pScrn, vgaRegPtr restore); + +
+ This function restores the VGA mode registers. They are restored + from the data in the vgaRegRec pointed to by + restore. The registers restored are: + + + MiscOut + CRTC[0-0x18] + Attribute[0-0x14] + Graphics[0-8] + Sequencer[0-4] + + + + + The number of registers actually restored may be modified by a prior call + to vgaHWSetRegCounts(). + + +
+ +
+ + void vgaHWRestoreFonts(ScrnInfoPtr pScrn, vgaRegPtr restore); + +
+ This function restores the text mode font and text data to the + video memory. The VGA memory window must be mapped with + vgaHWMapMem() before to calling this function. + + + + On some platforms, one or more of the font/text plane restores + may be no-ops. This is the case when the platform's VC driver + already takes care of this. + + +
+ +
+ + void vgaHWRestoreColormap(ScrnInfoPtr pScrn, vgaRegPtr restore); + +
+ This function restores the VGA colourmap (LUT). + + +
+ +
+ + void vgaHWInit(ScrnInfoPtr pScrn, DisplayModePtr mode); + +
+ This function fills in the vgaHWRec's + ModeReg field with the values appropriate for + programming the given video mode. It requires that the + ScrnInfoRec's depth field is + initialised, which determines how the registers are programmed. + + +
+ +
+ + void vgaHWSeqReset(vgaHWPtr hwp, Bool start); + +
+ Do a VGA sequencer reset. If start is TRUE, the + reset is started. If start is FALSE, the reset + is ended. + + +
+ +
+ + void vgaHWProtect(ScrnInfoPtr pScrn, Bool on); + +
+ This function protects VGA registers and memory from corruption + during loads. It is typically called with on set to + TRUE before programming, and with on set to + FALSE after programming. + + +
+ +
+ + Bool vgaHWSaveScreen(ScreenPtr pScreen, int mode); + +
+ This function blanks and unblanks the screen. It is blanked when + mode is SCREEN_SAVER_ON or + SCREEN_SAVER_CYCLE, and unblanked when + mode is SCREEN_SAVER_OFF or + SCREEN_SAVER_FORCER. + + +
+ +
+ + void vgaHWBlankScreen(ScrnInfoPtr pScrn, Bool on); + +
+ This function blanks and unblanks the screen. It is blanked when + on is FALSE, and unblanked when + on is TRUE. This function is + provided for use in cases where the ScrnInfoRec + can't be derived from the ScreenRec (while probing + for clocks, for example). + + +
+ + + + + VGA Colormap Functions + + + The vgahw module uses the standard colormap support (see the + Colormap Handling section. This is initialised + with the following function: + +
+ + Bool vgaHWHandleColormaps(ScreenPtr pScreen); + +
+ + + + + + VGA Register Access Functions + + + The vgahw module abstracts access to the standard VGA registers by + using a set of functions held in the vgaHWRec. When + the vgaHWRec is created these function pointers are + initialised with the set of standard VGA I/O register access functions. + In addition to these, the vgahw module includes a basic set of MMIO + register access functions, and the vgaHWRec function + pointers can be initialised to these by calling the + vgaHWSetMmioFuncs() function described above. Some + drivers/platforms may require a different set of functions for VGA + access. The access functions are described here. + + + +
+ + void writeCrtc(vgaHWPtr hwp, CARD8 index, CARD8 value); + +
+ Write value to CRTC register index. + + +
+ +
+ + CARD8 readCrtc(vgaHWPtr hwp, CARD8 index); + +
+ Return the value read from CRTC register index. + + +
+ +
+ + void writeGr(vgaHWPtr hwp, CARD8 index, CARD8 value); + +
+ Write value to Graphics Controller register + index. + + +
+ +
+ + CARD8 readGR(vgaHWPtr hwp, CARD8 index); + +
+ Return the value read from Graphics Controller register + index. + + +
+ +
+ + void writeSeq(vgaHWPtr hwp, CARD8 index, CARD8, value); + +
+ Write value to Sequencer register + index. + + +
+ +
+ + CARD8 readSeq(vgaHWPtr hwp, CARD8 index); + +
+ Return the value read from Sequencer register index. + + +
+ +
+ + void writeAttr(vgaHWPtr hwp, CARD8 index, CARD8, value); + +
+ Write value to Attribute Controller register + index. When writing out the index value this + function should set bit 5 (0x20) according to the + setting of hwp->paletteEnabled in order to + preserve the palette access state. It should be cleared when + hwp->paletteEnabled is TRUE + and set when it is FALSE. + + +
+ +
+ + CARD8 readAttr(vgaHWPtr hwp, CARD8 index); + +
+ Return the value read from Attribute Controller register + index. When writing out the index value this + function should set bit 5 (0x20) according to the + setting of hwp->paletteEnabled in order to + preserve the palette access state. It should be cleared when + hwp->paletteEnabled is TRUE + and set when it is FALSE. + + +
+ +
+ + void writeMiscOut(vgaHWPtr hwp, CARD8 value); + +
+ Write value to the Miscellaneous Output register. + + +
+ +
+ + CARD8 readMiscOut(vgwHWPtr hwp); + +
+ Return the value read from the Miscellaneous Output register. + + +
+ +
+ + void enablePalette(vgaHWPtr hwp); + +
+ Clear the palette address source bit in the Attribute Controller + index register and set hwp->paletteEnabled to + TRUE. + + +
+ +
+ + void disablePalette(vgaHWPtr hwp); + +
+ Set the palette address source bit in the Attribute Controller + index register and set hwp->paletteEnabled to + FALSE. + + +
+ +
+ + void writeDacMask(vgaHWPtr hwp, CARD8 value); + +
+ Write value to the DAC Mask register. + + +
+ +
+ + CARD8 readDacMask(vgaHWptr hwp); + +
+ Return the value read from the DAC Mask register. + + +
+ +
+ + void writeDacReadAddress(vgaHWPtr hwp, CARD8 value); + +
+ Write value to the DAC Read Address register. + + +
+ +
+ + void writeDacWriteAddress(vgaHWPtr hwp, CARD8 value); + +
+ Write value to the DAC Write Address register. + + +
+ +
+ + void writeDacData(vgaHWPtr hwp, CARD8 value); + +
+ Write value to the DAC Data register. + + +
+ +
+ + CARD8 readDacData(vgaHWptr hwp); + +
+ Return the value read from the DAC Data register. + + +
+ +
+ + CARD8 readEnable(vgaHWptr hwp); + +
+ Return the value read from the VGA Enable register. (Note: This + function is present in XFree86 4.1.0 and later.) + + +
+ +
+ + void writeEnable(vgaHWPtr hwp, CARD8 value); + +
+ Write value to the VGA Enable register. (Note: This + function is present in XFree86 4.1.0 and later.) + + +
+ + + + + Some notes about writing a driver + + NOTE: some parts of this are not up to date + + +The following is an outline for writing a basic unaccelerated driver +for a PCI video card with a linear mapped framebuffer, and which has a +VGA core. It is includes some general information that is relevant to +most drivers (even those which don't fit that basic description). + + + +The information here is based on the initial conversion of the Matrox +Millennium driver to the new design. For a fleshing out and sample +implementation of some of the bits outlined here, refer to that driver. +Note that this is an example only. The approach used here will not be +appropriate for all drivers. + + + +Each driver must reserve a unique driver name, and a string that is used +to prefix all of its externally visible symbols. This is to avoid name +space clashes when loading multiple drivers. The examples here are for +the ZZZ driver, which uses the ZZZ or zzz prefix for its externally +visible symbols. + + + + Include files + + + All drivers normally include the following headers: + + "xf86.h" + "xf86_OSproc.h" + "xf86_ansic.h" + "xf86Resources.h" + + Wherever inb/outb (and related things) are used the following should be + included: + + "compiler.h" + + Note: in drivers, this must be included after "xf86_ansic.h". + + + + Drivers that need to access PCI vendor/device definitions need this: + + "xf86PciInfo.h" + + + + + Drivers that need to access the PCI config space need this: + + "xf86Pci.h" + + + + + Drivers using the mi banking wrapper need: + + + "mibank.h" + + + + + Drivers that initialise a SW cursor need this: + + "mipointer.h" + + + + + All drivers implementing backing store need this: + + "mibstore.h" + + + + + All drivers using the mi colourmap code need this: + + "micmap.h" + + + + + If a driver uses the vgahw module, it needs this: + + "vgaHW.h" + + + + + Drivers supporting VGA or Hercules monochrome screens need: + + "xf1bpp.h" + + + + + Drivers supporting VGA or EGC 16-colour screens need: + + "xf4bpp.h" + + + + + Drivers using cfb need: + + #define PSZ 8 + #include "cfb.h" + #undef PSZ + + + + + Drivers supporting bpp 16, 24 or 32 with cfb need one or more of: + + "cfb16.h" + "cfb24.h" + "cfb32.h" + + + + + The driver's own header file: + + "zzz.h" + + + + + Drivers must NOT include the following: + + + "xf86Priv.h" + "xf86Privstr.h" + "xf86_libc.h" + "xf86_OSlib.h" + "Xos.h" + any OS header + + + + + + + Data structures and initialisation + + + + The following macros should be defined: + +#define VERSION <version-as-an-int> +#define ZZZ_NAME "ZZZ" /* the name used to prefix messages */ +#define ZZZ_DRIVER_NAME "zzz" /* the driver name as used in config file */ +#define ZZZ_MAJOR_VERSION <int> +#define ZZZ_MINOR_VERSION <int> +#define ZZZ_PATCHLEVEL <int> + + + + NOTE: ZZZ_DRIVER_NAME should match the name of the + driver module without things like the "lib" prefix, the "_drv" suffix + or filename extensions. + + + + + + A DriverRec must be defined, which includes the functions required + at the pre-probe phase. The name of this DriverRec must be an + upper-case version of ZZZ_DRIVER_NAME (for the purposes of static + linking). + +DriverRec ZZZ = { + VERSION, + ZZZ_DRIVER_NAME, + ZZZIdentify, + ZZZProbe, + ZZZAvailableOptions, + NULL, + 0 +}; + + + + + + Define list of supported chips and their matching ID: + +static SymTabRec ZZZChipsets[] = { + { PCI_CHIP_ZZZ1234, "zzz1234a" }, + { PCI_CHIP_ZZZ5678, "zzz5678a" }, + { -1, NULL } +}; + + + + The token field may be any integer value that the driver may use to + uniquely identify the supported chipsets. For drivers that support + only PCI devices using the PCI device IDs might be a natural choice, + but this isn't mandatory. For drivers that support both PCI and other + devices (like ISA), some other ID should probably used. When other + IDs are used as the tokens it is recommended that the names be + defined as an enum type. + + + + + + If the driver uses the xf86MatchPciInstances() + helper (recommended for drivers that support PCI cards) a list that + maps PCI IDs to chip IDs and fixed resources must be defined: + +static PciChipsets ZZZPciChipsets[] = { + { PCI_CHIP_ZZZ1234, PCI_CHIP_ZZZ1234, RES_SHARED_VGA }, + { PCI_CHIP_ZZZ5678, PCI_CHIP_ZZZ5678, RES_SHARED_VGA }, + { -1, -1, RES_UNDEFINED } +} + + + + + + + Define the XF86ModuleVersionInfo struct for the + driver. This is required for the dynamically loaded version: + +static XF86ModuleVersionInfo zzzVersRec = +{ + "zzz", + MODULEVENDORSTRING, + MODINFOSTRING1, + MODINFOSTRING2, + XF86_VERSION_CURRENT, + ZZZ_MAJOR_VERSION, ZZZ_MINOR_VERSION, ZZZ_PATCHLEVEL, + ABI_CLASS_VIDEODRV, + ABI_VIDEODRV_VERSION, + MOD_CLASS_VIDEODRV, + {0,0,0,0} +}; + + + + + + + Define a data structure to hold the driver's screen-specific data. + This must be used instead of global variables. This would be defined + in the "zzz.h" file, something like: + +typedef struct { + type1 field1; + type2 field2; + int fooHack; + Bool pciRetry; + Bool noAccel; + Bool hwCursor; + CloseScreenProcPtr CloseScreen; + OptionInfoPtr Options; + ... +} ZZZRec, *ZZZPtr; + + + + + + + Define the list of config file Options that the driver accepts. For + consistency between drivers those in the list of standard options + should be used where appropriate before inventing new options. + + +typedef enum { + OPTION_FOO_HACK, + OPTION_PCI_RETRY, + OPTION_HW_CURSOR, + OPTION_NOACCEL +} ZZZOpts; + +static const OptionInfoRec ZZZOptions[] = { + { OPTION_FOO_HACK, "FooHack", OPTV_INTEGER, {0}, FALSE }, + { OPTION_PCI_RETRY, "PciRetry", OPTV_BOOLEAN, {0}, FALSE }, + { OPTION_HW_CURSOR, "HWcursor", OPTV_BOOLEAN, {0}, FALSE }, + { OPTION_NOACCEL, "NoAccel", OPTV_BOOLEAN, {0}, FALSE }, + { -1, NULL, OPTV_NONE, {0}, FALSE } +}; + + + + + + + + Functions + + + + SetupProc + + + For dynamically loaded modules, a ModuleData + variable is required. It is should be the name of the driver + prepended to "ModuleData". A Setup() function is + also required, which calls xf86AddDriver() to add + the driver to the main list of drivers. + + + +static MODULESETUPPROTO(zzzSetup); + +XF86ModuleData zzzModuleData = { &zzzVersRec, zzzSetup, NULL }; + +static pointer +zzzSetup(pointer module, pointer opts, int *errmaj, int *errmin) +{ + static Bool setupDone = FALSE; + + /* This module should be loaded only once, but check to be sure. */ + + if (!setupDone) { + /* + * Modules that this driver always requires may be loaded + * here by calling LoadSubModule(). + */ + + setupDone = TRUE; + xf86AddDriver(&MGA, module, 0); + + /* + * The return value must be non-NULL on success even though + * there is no TearDownProc. + */ + return (pointer)1; + } else { + if (errmaj) *errmaj = LDR_ONCEONLY; + return NULL; + } +} + + + + + GetRec, FreeRec + + + A function is usually required to allocate the driver's + screen-specific data structure and hook it into the + ScrnInfoRec's driverPrivate field. + The ScrnInfoRec's driverPrivate is + initialised to NULL, so it is easy to check if the + initialisation has already been done. After allocating it, initialise + the fields. By using xnfcalloc() to do the allocation + it is zeroed, and if the allocation fails the server exits. + + + + NOTE: + When allocating structures from inside the driver which are defined + on the common level it is important to initialize the structure to + zero. + Only this guarantees that the server remains source compatible to + future changes in common level structures. + + + +static Bool +ZZZGetRec(ScrnInfoPtr pScrn) +{ + if (pScrn->driverPrivate != NULL) + return TRUE; + pScrn->driverPrivate = xnfcalloc(sizeof(ZZZRec), 1); + /* Initialise as required */ + ... + return TRUE; +} + + + + Define a macro in "zzz.h" which gets a pointer to + the ZZZRec when given pScrn: + + +#define ZZZPTR(p) ((ZZZPtr)((p)->driverPrivate)) + + + + + Define a function to free the above, setting it to NULL + once it has been freed: + + +static void +ZZZFreeRec(ScrnInfoPtr pScrn) +{ + if (pScrn->driverPrivate == NULL) + return; + xfree(pScrn->driverPrivate); + pScrn->driverPrivate = NULL; +} + + + + + + Identify + + + Define the Identify() function. It is run before + the Probe, and typically prints out an identifying message, which + might include the chipsets it supports. This function is mandatory: + + +static void +ZZZIdentify(int flags) +{ + xf86PrintChipsets(ZZZ_NAME, "driver for ZZZ Tech chipsets", + ZZZChipsets); +} + + + + + + Probe + + + Define the Probe() function. The purpose of this + is to find all instances of the hardware that the driver supports, + and for the ones not already claimed by another driver, claim the + slot, and allocate a ScrnInfoRec. This should be + a minimal probe, and it should under no circumstances leave the + state of the hardware changed. Because a device is found, don't + assume that it will be used. Don't do any initialisations other + than the required ScrnInfoRec initialisations. + Don't allocate any new data structures. + + + + This function is mandatory. + + + + NOTE: The xf86DrvMsg() functions cannot be used from + the Probe. + + + +static Bool +ZZZProbe(DriverPtr drv, int flags) +{ + Bool foundScreen = FALSE; + int numDevSections, numUsed; + GDevPtr *devSections; + int *usedChips; + int i; + + /* + * Find the config file Device sections that match this + * driver, and return if there are none. + */ + if ((numDevSections = xf86MatchDevice(ZZZ_DRIVER_NAME, + &devSections)) <= 0) { + return FALSE; + } + + /* + * Since this is a PCI card, "probing" just amounts to checking + * the PCI data that the server has already collected. If there + * is none, return. + * + * Although the config file is allowed to override things, it + * is reasonable to not allow it to override the detection + * of no PCI video cards. + * + * The provided xf86MatchPciInstances() helper takes care of + * the details. + */ + /* test if PCI bus present */ + if (xf86GetPciVideoInfo()) { + + numUsed = xf86MatchPciInstances(ZZZ_NAME, PCI_VENDOR_ZZZ, + ZZZChipsets, ZZZPciChipsets, devSections, + numDevSections, drv, &usedChips); + + for (i = 0; i < numUsed; i++) { + ScrnInfoPtr pScrn = NULL; + if ((pScrn = xf86ConfigPciEntity(pScrn, flags, usedChips[i], + ZZZPciChipsets, NULL, NULL, + NULL, NULL, NULL))) { + /* Allocate a ScrnInfoRec */ + pScrn->driverVersion = VERSION; + pScrn->driverName = ZZZ_DRIVER_NAME; + pScrn->name = ZZZ_NAME; + pScrn->Probe = ZZZProbe; + pScrn->PreInit = ZZZPreInit; + pScrn->ScreenInit = ZZZScreenInit; + pScrn->SwitchMode = ZZZSwitchMode; + pScrn->AdjustFrame = ZZZAdjustFrame; + pScrn->EnterVT = ZZZEnterVT; + pScrn->LeaveVT = ZZZLeaveVT; + pScrn->FreeScreen = ZZZFreeScreen; + pScrn->ValidMode = ZZZValidMode; + foundScreen = TRUE; + /* add screen to entity */ + } + } + xfree(usedChips); + } + +#ifdef HAS_ISA_DEVS + /* + * If the driver supports ISA hardware, the following block + * can be included too. + */ + numUsed = xf86MatchIsaInstances(ZZZ_NAME, ZZZChipsets, + ZZZIsaChipsets, drv, ZZZFindIsaDevice, + devSections, numDevSections, &usedChips); + for (i = 0; i < numUsed; i++) { + ScrnInfoPtr pScrn = NULL; + if ((pScrn = xf86ConfigIsaEntity(pScrn, flags, usedChips[i], + ZZZIsaChipsets, NULL, NULL, NULL, + NULL, NULL))) { + pScrn->driverVersion = VERSION; + pScrn->driverName = ZZZ_DRIVER_NAME; + pScrn->name = ZZZ_NAME; + pScrn->Probe = ZZZProbe; + pScrn->PreInit = ZZZPreInit; + pScrn->ScreenInit = ZZZScreenInit; + pScrn->SwitchMode = ZZZSwitchMode; + pScrn->AdjustFrame = ZZZAdjustFrame; + pScrn->EnterVT = ZZZEnterVT; + pScrn->LeaveVT = ZZZLeaveVT; + pScrn->FreeScreen = ZZZFreeScreen; + pScrn->ValidMode = ZZZValidMode; + foundScreen = TRUE; + } + } + xfree(usedChips); +#endif /* HAS_ISA_DEVS */ + + xfree(devSections); + return foundScreen; + + + + + AvailableOptions + + + Define the AvailableOptions() function. The purpose + of this is to return the available driver options back to the + -configure option, so that an xorg.conf file can be built and the + user can see which options are available for them to use. + + + + + PreInit + + + Define the PreInit() function. The purpose of + this is to find all the information required to determine if the + configuration is usable, and to initialise those parts of the + ScrnInfoRec that can be set once at the beginning + of the first server generation. The information should be found in + the least intrusive way possible. + + + + This function is mandatory. + + + + NOTES: + + + The PreInit() function is only called once + during the life of the X server (at the start of the first + generation). + + + + Data allocated here must be of the type that persists for + the life of the X server. This means that data that hooks into + the ScrnInfoRec's privates + field should be allocated here, but data that hooks into the + ScreenRec's devPrivates field + should not be allocated here. The driverPrivate + field should also be allocated here. + + + + Although the ScrnInfoRec has been allocated + before this function is called, the ScreenRec + has not been allocated. That means that things requiring it + cannot be used in this function. + + + + Very little of the ScrnInfoRec has been + initialised when this function is called. It is important to + get the order of doing things right in this function. + + + + + + +static Bool +ZZZPreInit(ScrnInfoPtr pScrn, int flags) +{ + /* Fill in the monitor field */ + pScrn->monitor = pScrn->confScreen->monitor; + + /* + * If using the vgahw module, it will typically be loaded + * here by calling xf86LoadSubModule(pScrn, "vgahw"); + */ + + /* + * Set the depth/bpp. Use the globally preferred depth/bpp. If the + * driver has special default depth/bpp requirements, the defaults should + * be specified here explicitly. + * We support both 24bpp and 32bpp framebuffer layouts. + * This sets pScrn->display also. + */ + if (!xf86SetDepthBpp(pScrn, 0, 0, 0, + Support24bppFb | Support32bppFb)) { + return FALSE; + } else { + if (depth/bpp isn't one we support) { + print error message; + return FALSE; + } + } + /* Print out the depth/bpp that was set */ + xf86PrintDepthBpp(pScrn); + + /* Set bits per RGB for 8bpp */ + if (pScrn->depth <= 8) { + /* Take into account a dac_6_bit option here */ + pScrn->rgbBits = 6 or 8; + } + + /* + * xf86SetWeight() and xf86SetDefaultVisual() must be called + * after pScrn->display is initialised. + */ + + /* Set weight/mask/offset for depth > 8 */ + if (pScrn->depth > 8) { + if (!xf86SetWeight(pScrn, defaultWeight, defaultMask)) { + return FALSE; + } else { + if (weight isn't one we support) { + print error message; + return FALSE; + } + } + } + + /* Set the default visual. */ + if (!xf86SetDefaultVisual(pScrn, -1)) { + return FALSE; + } else { + if (visual isn't one we support) { + print error message; + return FALSE; + } + } + + /* If the driver supports gamma correction, set the gamma. */ + if (!xf86SetGamma(pScrn, default_gamma)) { + return FALSE; + } + + /* This driver uses a programmable clock */ + pScrn->progClock = TRUE; + + /* Allocate the ZZZRec driverPrivate */ + if (!ZZZGetRec(pScrn)) { + return FALSE; + } + + pZzz = ZZZPTR(pScrn); + + /* Collect all of the option flags (fill in pScrn->options) */ + xf86CollectOptions(pScrn, NULL); + + /* + * Process the options based on the information in ZZZOptions. + * The results are written to pZzz->Options. If all of the options + * processing is done within this function a local variable "options" + * can be used instead of pZzz->Options. + */ + if (!(pZzz->Options = xalloc(sizeof(ZZZOptions)))) + return FALSE; + (void)memcpy(pZzz->Options, ZZZOptions, sizeof(ZZZOptions)); + xf86ProcessOptions(pScrn->scrnIndex, pScrn->options, pZzz->Options); + + /* + * Set various fields of ScrnInfoRec and/or ZZZRec based on + * the options found. + */ + from = X_DEFAULT; + pZzz->hwCursor = FALSE; + if (xf86IsOptionSet(pZzz->Options, OPTION_HW_CURSOR)) { + from = X_CONFIG; + pZzz->hwCursor = TRUE; + } + xf86DrvMsg(pScrn->scrnIndex, from, "Using %s cursor\n", + pZzz->hwCursor ? "HW" : "SW"); + if (xf86IsOptionSet(pZzz->Options, OPTION_NOACCEL)) { + pZzz->noAccel = TRUE; + xf86DrvMsg(pScrn->scrnIndex, X_CONFIG, + "Acceleration disabled\n"); + } else { + pZzz->noAccel = FALSE; + } + if (xf86IsOptionSet(pZzz->Options, OPTION_PCI_RETRY)) { + pZzz->UsePCIRetry = TRUE; + xf86DrvMsg(pScrn->scrnIndex, X_CONFIG, "PCI retry enabled\n"); + } + pZzz->fooHack = 0; + if (xf86GetOptValInteger(pZzz->Options, OPTION_FOO_HACK, + &pZzz->fooHack)) { + xf86DrvMsg(pScrn->scrnIndex, X_CONFIG, "Foo Hack set to %d\n", + pZzz->fooHack); + } + + /* + * Find the PCI slot(s) that this screen claimed in the probe. + * In this case, exactly one is expected, so complain otherwise. + * Note in this case we're not interested in the card types so + * that parameter is set to NULL. + */ + if ((i = xf86GetPciInfoForScreen(pScrn->scrnIndex, &pciList, NULL)) + != 1) { + print error message; + ZZZFreeRec(pScrn); + if (i > 0) + xfree(pciList); + return FALSE; + } + /* Note that pciList should be freed below when no longer needed */ + + /* + * Determine the chipset, allowing config file chipset and + * chipid values to override the probed information. The config + * chipset value has precedence over its chipid value if both + * are present. + * + * It isn't necessary to fill in pScrn->chipset if the driver + * keeps track of the chipset in its ZZZRec. + */ + + ... + + /* + * Determine video memory, fb base address, I/O addresses, etc, + * allowing the config file to override probed values. + * + * Set the appropriate pScrn fields (videoRam is probably the + * most important one that other code might require), and + * print out the settings. + */ + + ... + + /* Initialise a clockRanges list. */ + + ... + + /* Set any other chipset specific things in the ZZZRec */ + + ... + + /* Select valid modes from those available */ + + i = xf86ValidateModes(pScrn, pScrn->monitor->Modes, + pScrn->display->modes, clockRanges, + NULL, minPitch, maxPitch, rounding, + minHeight, maxHeight, + pScrn->display->virtualX, + pScrn->display->virtualY, + pScrn->videoRam * 1024, + LOOKUP_BEST_REFRESH); + if (i == -1) { + ZZZFreeRec(pScrn); + return FALSE; + } + + /* Prune the modes marked as invalid */ + + xf86PruneDriverModes(pScrn); + + /* If no valid modes, return */ + + if (i == 0 || pScrn->modes == NULL) { + print error message; + ZZZFreeRec(pScrn); + return FALSE; + } + + /* + * Initialise the CRTC fields for the modes. This driver expects + * vertical values to be halved for interlaced modes. + */ + xf86SetCrtcForModes(pScrn, INTERLACE_HALVE_V); + + /* Set the current mode to the first in the list. */ + pScrn->currentMode = pScrn->modes; + + /* Print the list of modes being used. */ + xf86PrintModes(pScrn); + + /* Set the DPI */ + xf86SetDpi(pScrn, 0, 0); + + /* Load bpp-specific modules */ + switch (pScrn->bitsPerPixel) { + case 1: + mod = "xf1bpp"; + break; + case 4: + mod = "xf4bpp"; + break; + case 8: + mod = "cfb"; + break; + case 16: + mod = "cfb16"; + break; + case 24: + mod = "cfb24"; + break; + case 32: + mod = "cfb32"; + break; + } + if (mod && !xf86LoadSubModule(pScrn, mod)) + ZZZFreeRec(pScrn); + return FALSE; + + /* Load XAA if needed */ + if (!pZzz->noAccel || pZzz->hwCursor) + if (!xf86LoadSubModule(pScrn, "xaa")) { + ZZZFreeRec(pScrn); + return FALSE; + } + + /* Done */ + return TRUE; +} + + + + + MapMem, UnmapMem + + + Define functions to map and unmap the video memory and any other + memory apertures required. These functions are not mandatory, but + it is often useful to have such functions. + + + +static Bool +ZZZMapMem(ScrnInfoPtr pScrn) +{ + /* Call xf86MapPciMem() to map each PCI memory area */ + ... + return TRUE or FALSE; +} + +static Bool +ZZZUnmapMem(ScrnInfoPtr pScrn) +{ + /* Call xf86UnMapVidMem() to unmap each memory area */ + ... + return TRUE or FALSE; +} + + + + + Save, Restore + + + Define functions to save and restore the original video state. These + functions are not mandatory, but are often useful. + + + +static void +ZZZSave(ScrnInfoPtr pScrn) +{ + /* + * Save state into per-screen data structures. + * If using the vgahw module, vgaHWSave will typically be + * called here. + */ + ... +} + +static void +ZZZRestore(ScrnInfoPtr pScrn) +{ + /* + * Restore state from per-screen data structures. + * If using the vgahw module, vgaHWRestore will typically be + * called here. + */ + ... +} + + + + + ModeInit + + + Define a function to initialise a new video mode. This function isn't + mandatory, but is often useful. + + + +static Bool +ZZZModeInit(ScrnInfoPtr pScrn, DisplayModePtr mode) +{ + /* + * Program a video mode. If using the vgahw module, + * vgaHWInit and vgaRestore will typically be called here. + * Once up to the point where there can't be a failure + * set pScrn->vtSema to TRUE. + */ + ... +} + + + + + ScreenInit + + + Define the ScreenInit() function. This is called + at the start of each server generation, and should fill in as much + of the ScreenRec as possible as well as any other + data that is initialised once per generation. It should initialise + the framebuffer layers it is using, and initialise the initial video + mode. + + + + This function is mandatory. + + + + NOTE: The ScreenRec (pScreen) is + passed to this driver, but it and the + ScrnInfoRecs are not yet hooked into each + other. This means that in this function, and functions it + calls, one cannot be found from the other. + + + +static Bool +ZZZScreenInit(int scrnIndex, ScreenPtr pScreen, int argc, char **argv) +{ + /* Get the ScrnInfoRec */ + pScrn = xf86Screens[pScreen->myNum]; + + /* + * If using the vgahw module, its data structures and related + * things are typically initialised/mapped here. + */ + + /* Save the current video state */ + ZZZSave(pScrn); + + /* Initialise the first mode */ + ZZZModeInit(pScrn, pScrn->currentMode); + + /* Set the viewport if supported */ + + ZZZAdjustFrame(scrnIndex, pScrn->frameX0, pScrn->frameY0, 0); + + /* + * Setup the screen's visuals, and initialise the framebuffer + * code. + */ + + /* Reset the visual list */ + miClearVisualTypes(); + + /* + * Setup the visuals supported. This driver only supports + * TrueColor for bpp > 8, so the default set of visuals isn't + * acceptable. To deal with this, call miSetVisualTypes with + * the appropriate visual mask. + */ + + if (pScrn->bitsPerPixel > 8) { + if (!miSetVisualTypes(pScrn->depth, TrueColorMask, + pScrn->rgbBits, pScrn->defaultVisual)) + return FALSE; + } else { + if (!miSetVisualTypes(pScrn->depth, + miGetDefaultVisualMask(pScrn->depth), + pScrn->rgbBits, pScrn->defaultVisual)) + return FALSE; + } + + /* + * Initialise the framebuffer. + */ + + switch (pScrn->bitsPerPixel) { + case 1: + ret = xf1bppScreenInit(pScreen, FbBase, + pScrn->virtualX, pScrn->virtualY, + pScrn->xDpi, pScrn->yDpi, + pScrn->displayWidth); + break; + case 4: + ret = xf4bppScreenInit(pScreen, FbBase, + pScrn->virtualX, pScrn->virtualY, + pScrn->xDpi, pScrn->yDpi, + pScrn->displayWidth); + break; + case 8: + ret = cfbScreenInit(pScreen, FbBase, + pScrn->virtualX, pScrn->virtualY, + pScrn->xDpi, pScrn->yDpi, + pScrn->displayWidth); + break; + case 16: + ret = cfb16ScreenInit(pScreen, FbBase, + pScrn->virtualX, pScrn->virtualY, + pScrn->xDpi, pScrn->yDpi, + pScrn->displayWidth); + break; + case 24: + ret = cfb24ScreenInit(pScreen, FbBase, + pScrn->virtualX, pScrn->virtualY, + pScrn->xDpi, pScrn->yDpi, + pScrn->displayWidth); + break; + case 32: + ret = cfb32ScreenInit(pScreen, FbBase, + pScrn->virtualX, pScrn->virtualY, + pScrn->xDpi, pScrn->yDpi, + pScrn->displayWidth); + break; + default: + print a message about an internal error; + ret = FALSE; + break; + } + + if (!ret) + return FALSE; + + /* Override the default mask/offset settings */ + if (pScrn->bitsPerPixel > 8) { + for (i = 0, visual = pScreen->visuals; + i < pScreen->numVisuals; i++, visual++) { + if ((visual->class | DynamicClass) == DirectColor) { + visual->offsetRed = pScrn->offset.red; + visual->offsetGreen = pScrn->offset.green; + visual->offsetBlue = pScrn->offset.blue; + visual->redMask = pScrn->mask.red; + visual->greenMask = pScrn->mask.green; + visual->blueMask = pScrn->mask.blue; + } + } + } + + /* + * If banking is needed, initialise an miBankInfoRec (defined in + * "mibank.h"), and call miInitializeBanking(). + */ + if (!miInitializeBanking(pScreen, pScrn->virtualX, pScrn->virtualY, + pScrn->displayWidth, pBankInfo)) + return FALSE; + + /* + * If backing store is to be supported (as is usually the case), + * initialise it. + */ + miInitializeBackingStore(pScreen); + + /* + * Set initial black & white colourmap indices. + */ + xf86SetBlackWhitePixels(pScreen); + + /* + * Install colourmap functions. If using the vgahw module, + * vgaHandleColormaps would usually be called here. + */ + + ... + + /* + * Initialise cursor functions. This example is for the mi + * software cursor. + */ + miDCInitialize(pScreen, xf86GetPointerScreenFuncs()); + + /* Initialise the default colourmap */ + switch (pScrn->depth) { + case 1: + if (!xf1bppCreateDefColormap(pScreen)) + return FALSE; + break; + case 4: + if (!xf4bppCreateDefColormap(pScreen)) + return FALSE; + break; + default: + if (!cfbCreateDefColormap(pScreen)) + return FALSE; + break; + } + + /* + * Wrap the CloseScreen vector and set SaveScreen. + */ + ZZZPTR(pScrn)->CloseScreen = pScreen->CloseScreen; + pScreen->CloseScreen = ZZZCloseScreen; + pScreen->SaveScreen = ZZZSaveScreen; + + /* Report any unused options (only for the first generation) */ + if (serverGeneration == 1) { + xf86ShowUnusedOptions(pScrn->scrnIndex, pScrn->options); + } + + /* Done */ + return TRUE; +} + + + + + SwitchMode + + + Define the SwitchMode() function if mode switching + is supported by the driver. + + + +static Bool +ZZZSwitchMode(int scrnIndex, DisplayModePtr mode, int flags) +{ + return ZZZModeInit(xf86Screens[scrnIndex], mode); +} + + + + + AdjustFrame + + + Define the AdjustFrame() function if the driver + supports this. + + + +static void +ZZZAdjustFrame(int scrnIndex, int x, int y, int flags) +{ + /* Adjust the viewport */ +} + + + + + EnterVT, LeaveVT + + + Define the EnterVT() and LeaveVT() + functions. + + + + These functions are mandatory. + + + +static Bool +ZZZEnterVT(int scrnIndex, int flags) +{ + ScrnInfoPtr pScrn = xf86Screens[scrnIndex]; + return ZZZModeInit(pScrn, pScrn->currentMode); +} + +static void +ZZZLeaveVT(int scrnIndex, int flags) +{ + ScrnInfoPtr pScrn = xf86Screens[scrnIndex]; + ZZZRestore(pScrn); +} + + + + + CloseScreen + + + Define the CloseScreen() function: + + + + This function is mandatory. Note that it unwraps the previously + wrapped pScreen->CloseScreen, and finishes by + calling it. + + + +static Bool +ZZZCloseScreen(int scrnIndex, ScreenPtr pScreen) +{ + ScrnInfoPtr pScrn = xf86Screens[scrnIndex]; + if (pScrn->vtSema) { + ZZZRestore(pScrn); + ZZZUnmapMem(pScrn); + } + pScrn->vtSema = FALSE; + pScreen->CloseScreen = ZZZPTR(pScrn)->CloseScreen; + return (*pScreen->CloseScreen)(scrnIndex, pScreen); +} + + + + + SaveScreen + + + Define the SaveScreen() function (the screen + blanking function). When using the vgahw module, this will typically + be: + + +static Bool +ZZZSaveScreen(ScreenPtr pScreen, int mode) +{ + return vgaHWSaveScreen(pScreen, mode); +} + + + + + This function is mandatory. Before modifying any hardware register + directly this function needs to make sure that the Xserver is active + by checking if pScrn is non-NULL and for + pScrn->vtSema == TRUE. + + + + + FreeScreen + + + Define the FreeScreen() function. This function + is optional. It should be defined if the ScrnInfoRec + driverPrivate field is used so that it can be freed + when a screen is deleted by the common layer for reasons possibly + beyond the driver's control. This function is not used in during + normal (error free) operation. The per-generation data is freed by + the CloseScreen() function. + + + +static void +ZZZFreeScreen(int scrnIndex, int flags) +{ + /* + * If the vgahw module is used vgaHWFreeHWRec() would be called + * here. + */ + ZZZFreeRec(xf86Screens[scrnIndex]); +} + + + + + + + + + +
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