;**************************************************************************** ;* ;* The Universal VESA VBE ;* ;* Copyright (C) 1993 Kendall Bennett. ;* All rights reserved. ;* ;* Filename: $RCSfile: vesavbe.asm $ ;* Version: $Revision: 1.3 $ ;* ;* Language: 8086 Assembler ;* Environment: IBM PC (MS DOS) ;* ;* Description: This source file contains the code for a Universal VESA VBE ;* TSR, to implement the VESA Video BIOS Extensions (VBE) for ;* supported SuperVGA's. ;* ;* Note that this VESA VBE will also support bank switching ;* and page flipping for the _standard_ VGA video modes, as ;* well as the SuperVGA modes. ;* ;* Must be assembled in the large memory model. ;* ;* $Id: vesavbe.asm 1.3 1993/09/24 05:22:51 kjb release $ ;* ;* Revision History: ;* ----------------- ;* ;* $Log: vesavbe.asm $ ;* Revision 1.3 1993/09/24 05:22:51 kjb ;* Fixed a number of bugs. ;* ;* Revision 1.2 1993/09/23 03:30:25 kjb ;* Fixed bugs with Paradise, Trident, S3 and others... ;* ;* Revision 1.1 1993/09/19 01:26:40 kjb ;* Initial revision ;* ;**************************************************************************** IDEAL DOSSEG JUMPS INCLUDE "MODEL.MAC" ; Memory model macros header main ; Link with main.c ;---------------------------------------------------------------------------- ; Internal Equates and Macros ;---------------------------------------------------------------------------- INCLUDE "CHIPSETS.EQU" ; Include Equates for Mgraph Routines CRTC EQU 3D4h ; Port of CRTC registers VGABufferSeg EQU 0A000h ; Segment of VGA display memory NL EQU <0dh, 0ah> ; New Line marker EOS EQU '$' ; End of String marker PSPSize EQU 100h ; Size of program PSP SUCCESS EQU 004Fh ; Return value on success FAILURE EQU 014Fh ; Return value on failure VBE_FUNCTIONS EQU 04Fh ; VBE Control function value (AH) MAX_FUNCTION EQU 8 ; Highest VBE function number supported VBE_VERSION EQU 0102h ; Version 1.2 NOT_VALID EQU 0FFFFh ; Flags function is not valid WRITE_BUF_SIZE EQU 058h ; Size of buffer for write bank routine READ_BUF_SIZE EQU 025h ; Size of buffer for read bank routine PAGE_BUF_SIZE EQU 053h ; Size of buffer for paging routine SETUP_BUF_SIZE EQU 046h ; Size of buffer for SuperVGA setup EXIT_BUF_SIZE EQU 01Eh ; Size of buffer for SuperVGA exit DAC_BUF_SIZE EQU 01h ; Size of buffer for DAC routines ; Macro to get the value of an interrupt vector. Returns the result in ; ES:BX. MACRO GetVector intnum mov ah,35h mov al,intnum int 21h ENDM ; Macro to set the value of an interrupt vector. MACRO SetVector intnum, handler push ds mov dx,seg handler mov ds,dx mov dx,offset handler mov ah,25h mov al,intnum int 21h pop ds ENDM ; Macro to simulate and Int 10h to the old VIDEO BIOS. We need to ensure ; mutually exclusive access to our VBE routines, so we need to modify ; a flag that to let us know if the underlying BIOS has made a direct ; call to us, and pass this call back to the BIOS. MACRO CallOldBIOS inc [InsideVBE] ; Ensure mutal exclusion! pushf call [OldInt10] ; Call the old BIOS dec [InsideVBE] ENDM ; Macro to set the low start address bits, and to load BX with the ; top bits for SuperVGA adapters. MACRO SetLowStartAddress mov dx,03D4h ; DX := CRTC I/O port (3D4h) mov ax,bx out dx,ax mov ax,cx out dx,ax mov bx,si ; BX := Bits 16+ for start address ENDM ; Macro to set the low start address bits, and to load BX with the ; top bits for SuperVGA adapters. This version is for modes where the ; start address value is in 8 byte increments rather than 4 byte increments ; in 256 color modes, so we must shift the start address right 1 bit. MACRO SetLowStartAddress256 mov al,bl ; Save value of BL mov bl,bh mov bh,ch ; BX := start address bits 15-0 shr si,1 rcr bx,1 ; Shift entire address right 1 bit mov ch,bh ; CH := Bits 15-8 of start address mov bh,bl ; BH := Bits 7-0 of start address mov bl,al ; BL := index of start address low register mov dx,03D4h ; DX := CRTC I/O port (3D4h) mov ax,bx out dx,ax mov ax,cx out dx,ax mov bx,si ; BX := Bits 16+ for start address ENDM ; Macros to do simplified port I/O. Don't use these were speed is of ; the essence, but only as a convenience. MACRO inp port mov dx,port ;; Read a byte from port 'port' into al in al,dx ENDM MACRO outp port, value mov dx,port ;; Write a byte to port 'port' mov al,value out dx,al ENDM MACRO rdinx port, index mov dx,port ;; Read register 'port' index 'index' mov al,index out dx,al inc dx in al,dx ;; Result in AL ENDM MACRO wrinx port, index, val mov al,index ;; Write 'port' index 'index' with 'val' mov ah,val mov dx,port out dx,ax ENDM MACRO modinx port, index, mask, nvw mov dx,port mov al,index out dx,al inc dx in al,dx ;; Read the old value and al,not mask ;; Mask out bits to be changed or al,nvw ;; Or in the changed bits out dx,al ;; Write the value back again ENDM MACRO dacToPel mov dx,3C8h in al,dx ENDM MACRO dacToCommand mov dx,3C8h in al,dx mov dx,3C6h in al,dx in al,dx in al,dx in al,dx ENDM begcodeseg test EXTRN _testISR:FAR endcodeseg test begcodeseg main EXTRN __psp:WORD ; Segment of program PSP ;---------------------------------------------------------------------------- ; Resident Data ;---------------------------------------------------------------------------- ; Signature used to determine if the TSR is already installed. Signature: db 'Universal VESA VBE 4.0',0 SigLen = $-Signature LABEL OldInt10 DWORD OldInt10off dw ? ; Place to save int 10h vector OldInt10seg dw ? InsideVBE dw false ; True if inside VBE ISR routine VBECompliant dw ? ; Version if BIOS is VBE already ; Globals used by resident driver CntSuperVGA dw 0 ; Installed SuperVGA CntChipID dw 0 ; Graphics driver chip ID CntMemory dw 0 ; Amount of memory on chip CntDAC dw 0 ; Video DAC ID CntColors dw 0 ; Current color mode CntMode dw 0 ; Current VBE mode number CurBytesPerLine dw 0 ; Current bytes per line value CntStartX dw 0 ; Current display start X CntStartY dw 0 ; Current display start Y CntDacWidth db 6 ; Current DAC width CurBank dw 0 ; Current window bank number ; Vectors to routines currently in use. The information within the PMInfo ; block can be obtained upon special request by application programs ; via the GetModeInfo routine with the mode number set to -1. The routines ; may then be relocated into the programs own address space for faster ; execution in protected mode (and also real mode). Please consult the ; programming information guide about this, as the interface to these ; routines is different to the VESA VBE routines. TwoBanks dw false ; Flags if two banks available PMInfo: WriteBankLen dw ? ; Relocatable length of write bank routine WriteBank dw NOT_VALID ; Address of current write bank routine dw seg NewPage16Buf ReadBankLen dw ? ; Relocatable lenth of read bank routine ReadBank dw NOT_VALID ; Address of current read bank routine dw seg NewPage16Buf NewPageLen dw ? ; Relocatable size of page routine NewPage dw NOT_VALID ; Address of page flipping routine dw seg NewPage16Buf PMInfoSize = ($-PMInfo) ; Vectors to all routines used by the resident driver. WriteBank16 dw NOT_VALID ; Address of 16 color write bank routine WriteBank16Len dw 0 ; Size of 16 color write bank routine ReadBank16 dw NOT_VALID ; Address of 16 color read bank routine ReadBank16Len dw 0 ; Size of 16 color read bank routine WriteBank256 dw NOT_VALID ; Address of 256 color write bank routine WriteBank256Len dw 0 ; Size of 256 color write bank routine ReadBank256 dw NOT_VALID ; Address of 256 color read bank routine ReadBank256Len dw 0 ; Size of 256 color read bank routine NewPage16 dw NOT_VALID ; Address of 16 color page flipping routine NewPage16Len dw 0 ; Relocatable size of page routine NewPage256 dw NOT_VALID ; Address of 256 color page flipping routine NewPage256Len dw 0 ; Relocatable size of page routine SetupSVGA dw NOT_VALID ; Address of SuperVGA setup routine SetupSVGALen dw 0 ; Size of SuperVGA setup routine ExitSVGA dw NOT_VALID ; Address of SuperVGA exit routine ExitSVGALen dw 0 ; Size of SuperVGA exit routine Set8BitDac dw NOT_VALID ; Set the DAC to 8 bits wide Set8BitDacLen dw 0 ; Size of DAC routine Set6BitDac dw NOT_VALID ; Set the DAC to 6 bits wide Set6BitDacLen dw 0 ; Size of DAC routine ; Dispatch table for supported function calls DispatchTable dw offset SuperVGAInfo dw seg SuperVGAInfo dw offset SuperVGAModeInfo dw seg SuperVGAModeInfo dw offset SuperVGASetMode dw seg SuperVGASetMode dw offset SuperVGAGetMode dw seg SuperVGAGetMode dw offset SuperVGAVideoState dw seg SuperVGAVideoState dw offset SuperVGABankSwitch dw seg SuperVGABankSwitch dw offset SuperVGAScanlineLength dw seg SuperVGAScanlineLength dw offset SuperVGADisplayStart dw seg SuperVGADisplayStart dw offset SuperVGADACControl dw seg SuperVGADaCControl DispatchFunc dd ? ; VGA Information block returned to the user program VGAInfo db 'VESA' ; Signature value dw VBE_VERSION ; VBE Version number dw offset Signature ; OEM Name offset dw seg Signature ; OEM Name segment db 4 DUP (0) ; Capabilities bits dw offset ModeTable ; Video mode table offset dw seg ModeTable ; Video mode table segment VBEMemSize db 0 ; Memory size in 64k lots VGAInfoSize = ($-VGAInfo) ; Video mode information block filled in a passed to the user application. ; BIOS output is generally supported by most video modes, but we can never ; be sure so we turn this off for all modes. ModeInfo dw 011011b ; Mode Attributes WinAAttr db 0111b ; Window A attributes WinBAttr db 0011b ; Window B attributes dw 64 ; Window granularity (in K) dw 64 ; Window size (in K) dw VGABufferSeg ; Start segment of Window A dw VGABufferSeg ; Start segment of Window B dw offset SuperVGABankSwitch dw seg SuperVGABankSwitch BytesPerLine dw 0 ; Bytes per logical scanline XRes dw 0 ; X resolution YRes dw 0 ; Y resolution CWidth db 0 ; Character width CHeight db 0 ; Character height Planes db 0 ; Number of planes BitsPerPixel db 0 ; Bits per pixel Banks db 0 ; Number of banks MemMode db 0 ; Memory mode BankSize db 0 ; Bank size Pages db 0 ; Number of image pages db 1 ; Reserved RedMaskSize db 0 ; Red mask size RedMaskPos db 0 ; Red mask position GreenMaskSize db 0 ; Green mask size GreenMaskPos db 0 ; Green mask pos BlueMaskSize db 0 ; Blue mask size BlueMaskPos db 0 ; Blue mask position ResMaskSize db 0 ; Reserved mask size ResMaskPos db 0 ; Reserved mask pos DirectInfo db 0 ; Direct screen mode info ModeInfoSize = ($-ModeInfo) ; Table to construct the mask position information for direct video ; modes. maskDefInfo db 00h,00h,00h,00h,00h,00h,00h,00h,00h mask32kInfo db 05h,0Ah,05h,05h,05h,00h,01h,0Bh,02h mask64kInfo db 05h,0Bh,06h,05h,05h,00h,00h,00h,00h mask16mInfo db 08h,10h,08h,08h,08h,00h,00h,00h,00h maskInfoSize = ($-mask16mInfo) ; List of all possible supported VBE video modes. This will be filled ; in by the high level language code during the detection phase. ModeTable dw 31 dup (?) ; Index Table for filling in the above mode information table and for ; finding the values to use to initialise a video mode via int 10h. This ; table is constructed and copied here by the high level code. Refer ; to the 'detect.c' file for information on it's structure. INDEX_ENTRY_SIZE = 20 PARTIAL_INDEX_SIZE = 14 IndexTable db (31 * INDEX_ENTRY_SIZE) dup (?) ;---------------------------------------------------------------------------- ; Resident Code ;---------------------------------------------------------------------------- ASSUME cs:main_TEXT, ds:NOTHING, es:NOTHING ;---------------------------------------------------------------------------- ; Int10ISR - Video BIOS hook. ;---------------------------------------------------------------------------- ; ; This routine is called whenever an application program makes a call to ; the Video BIOS routines. We check to see if the calls and VBE functions ; calls, and handle them appropriately, or else we simply pass the call ; to the old Video BIOS handler. ; ;---------------------------------------------------------------------------- PROC Int10ISR far ; Some BIOSes directly call themselves to get things done, which can cause ; the ISR routines to get into an infinite loop. Thus we have a special flag ; to tell us if we are already in the ISR at level one, and to simply call ; the underlying VIDEO BIOS directly rather than processing the call ; ourselves since we made the call anyway :-) sti cmp [InsideVBE],0 jne @@ToOldBIOS cmp ah,VBE_FUNCTIONS ; Is this a VBE function? je @@VBEFunction ; Yes, so handle it ; Check to see if this is the Set Video Mode function, in which case we ; need to check if we are trying to set a standard VGA video mode. or ah,ah jnz @@ToOldBIOS cmp al,0Dh jb @@ToOldBIOS cmp al,13h ja @@ToOldBIOS ; Attempting to set a standard VGA video mode, so pass this call onto the ; SuperVGASetMode routine. mov bx,ax ; BX := video mode number push si ; Save registers push di push ds push es call SuperVGASetMode ; Set the video mode pop es pop ds ; Restore value of registers pop di pop si iret @@ToOldBIOS: jmp [OldInt10] ; Jump to old VIDEO BIOS @@VBEFunction: cmp al,MAX_FUNCTION ja @@ToOldBIOS ; Not one of ours, so pass it on ; This is a VBE function, so dispatch to the appropriate routine depending ; on the subfunction number. xor ah,ah shl al,2 ; AX := index into table push bx ; Save value of BX mov bx,ax mov ax,[DispatchTable + bx] mov [WORD DispatchFunc],ax mov ax,[DispatchTable + bx + 2] mov [WORD DispatchFunc+2],ax pop bx ; Restore BX call [DispatchFunc] ; Call the appropriate function iret ENDP Int10ISR ;---------------------------------------------------------------------------- ; SuperVGAInfo - Get SuperVGA Information ;---------------------------------------------------------------------------- ; ; Function to return information about the SuperVGA video card. ; ; Entry: ES:DI -> 256byte buffer for SuperVGA information ; ; Exit: AX - VBE status code ; ;---------------------------------------------------------------------------- PROC SuperVGAInfo far push si ; Save registers push di push ds push es mov ax,cs mov ds,ax mov si,offset VGAInfo ; DS:SI -> VGAInfo Table mov cx,VGAInfoSize cld rep movsb ; Copy the data across xor ax,ax mov cx,256-VGAInfoSize rep stosb ; Clear out remaining buffer mov ax,SUCCESS ; Return status code pop es pop ds ; Restore value of registers pop di pop si ret ENDP SuperVGAInfo ;---------------------------------------------------------------------------- ; SuperVGAModeInfo - Get SuperVGA Video Mode Information ;---------------------------------------------------------------------------- ; ; Function to return information about a specific VBE SuperVGA video mode. ; ; If CX := -1, we return information about how to access the relocatable ; bank switching and page flipping routines. ; ; Entry: CX - SuperVGA video mode ; ES:DI -> 256 byte buffer for mode information ; ; Exit: AX - VBE status code ; ;---------------------------------------------------------------------------- PROC SuperVGAModeInfo far push si ; Save registers push di push ds push es cmp cx,-1 ; Our special function call? je @@DoSpecial ; Yes, handle it... ; Determine if the video mode is one of our valid video modes. call ValidateVBEMode ; DS:SI -> Index Table entry cmp si,-1 je @@Invalid ; Video mode is invalid to us!! ; Copy the information specific to the video mode into buffer push es push di ; Save position of user buffer add si,2 ; Increment to start of mode info push cs pop es mov di,offset BytesPerLine ; ES:DI -> Destination buffer mov cx,PARTIAL_INDEX_SIZE cld rep movsb ; Copy the data across ; Now copy the mask information across. This will be cleared for non ; direct color modes. mov cx,maskInfoSize mov di,offset RedMaskSize mov si,offset maskDefInfo mov dl,[BitsPerPixel] cmp dl,15 ; 32k color mode? jl @@CopyMask ; No, must be 16 or 256 mov si,offset mask32kInfo cmp dl,16 ; 64k color mode? jl @@CopyMask ; No, must be 32k color mode mov si,offset mask64kInfo cmp dl,24 ; 16m color mode? jl @@CopyMask ; No, must be 64k color mode mov si,offset mask16mInfo @@CopyMask: rep movsb ; Copy mask information across ; Copy the mode information across into application buffer pop di pop es ; ES:DI -> User mode info buffer mov si,offset ModeInfo ; DS:SI -> ModeInfo Table mov cx,ModeInfoSize rep movsb ; Copy the data across xor ax,ax mov cx,256-ModeInfoSize rep stosb ; Clear out remaining buffer @@Exit: pop es pop ds ; Restore value of registers pop di pop si mov ax,SUCCESS ret @@DoSpecial: push cs pop ds mov si,offset PMInfo ; DS:SI -> Protected mode information mov cx,PMInfoSize rep movsb ; Copy the information across... mov cx,0CABDh ; Flag that we are here!! jmp @@Exit ; The video mode is invalid, but the underlying video BIOS may be VBE ; compatible, and the mode number may mean something to it, so we pass it ; on to it. @@Invalid: pop es pop ds ; Restore value of registers pop di pop si mov ax,4F01h CallOldBIOS ret ENDP SuperVGAModeInfo ;---------------------------------------------------------------------------- ; SuperVGASetMode - Set SuperVGA Video Mode ;---------------------------------------------------------------------------- ; ; Function to set a specific VBE SuperVGA video mode. Only graphics modes ; are supported by this TSR. Text modes are passed to an underlying VBE ; if one is present. ; ; Not that we also handle the setting of standard video modes in this ; routine, since we need to be able to setup the correct bank switching and ; paging routines to work with this video mode. ; ; Entry: BX - VBE video mode number (bit 15 means don't clear mem). ; ; Exit: AX - VBE status code. ; ;---------------------------------------------------------------------------- PROC SuperVGASetMode far push si ; Save registers push di push ds push es mov cx,bx and cl,7Fh cmp cx,13h ja @@VBEMode ; Attempting to set a standard VGA video mode, so save the current ; color mode for the mode and get the BIOS to initialise it. Note that we ; call the SuperVGA exit routine first to bring the SuperVGA back into ; it's default state. We also reset the DAC back to normal DAC mode ; in case the BIOS does not do this correctly. cmp [ExitSVGA],NOT_VALID je @@1 call [ExitSVGA] ; Call the SuperVGA exit code @@1: dacToCommand xor al,al out dx,al ; Reset DAC to normal mode dacToPel push cx push bx mov [CntColors],gr16Color ; Assume 16 color mode cmp cx,13h jl @@2 mov [CntColors],gr256Color ; Nope, must be 256 color mode @@2: mov [CntMode],cx ; Save the current mode number mov [CurBytesPerLine],40 cmp cx,0Dh je @@SetVGAMode mov [CurBytesPerLine],80 cmp cx,13h jl @@SetVGAMode mov [CurBytesPerLine],320 @@SetVGAMode: pop ax ; AX := mode number to set CallOldBIOS ; Get BIOS to initialise the mode pop cx ; Restore value of VBE mode cmp [CntMode],3 jl @@Done cmp [CntMode],13h ja @@Done jmp @@StandardVGAMode ; We have a VBE mode to set. First we need to find the correct mode ; information table entry, and lookup the values we need to get the ; BIOS to initialise the video mode. @@VBEMode: push bx ; Save VBE mode number for later mov cx,bx and ch,07Fh ; Clear memory clear bit call ValidateVBEMode ; DS:SI -> Mode information buffer cmp si,-1 je @@InvalidMode ; Video mode is invalid to us! mov [CntMode],cx ; Save current mode number mov ax,[si+16] ; AX := AXVal from mode info mov bx,[si+18] ; BX := BXVal from mode info mov dx,[si+2] ; DX := BytesPerLine value mov [CurBytesPerLine],dx; Save the BytesPerLine value for mode mov dl,[si+11] ; DL := BitsPerPixel pop cx ; CX := VBE mode number and ch,80h ; isolate clear memory bit jz @@SetMode ; Bit is not set, so simply set the mode ; Request was made to _not_ clear the video memory, so attempt to set the ; correct bit for the OEM video modes. or bx,bx ; BX := 0, so AX := video mode number jz @@SetAX or bh,bh jz @@SetBL or bh,80h ; Set the memory clear bit jmp @@SetMode @@SetAX: or al,80h ; Set the memory clear bit jmp @@SetMode @@SetBL: or bl,80h ; Set the memory clear bit @@SetMode: push dx ; Preserve bits per pixel value CallOldBIOS ; Call the BIOS to initialise the mode pop dx mov ax,40h mov es,ax cmp [BYTE es:49h],3 ; Mode is still text mode, did not set jbe @@ModeSetFailed ; Save the current color mode that we are in for correct bank switching ; and CRT addressing. mov [CntColors],gr16Color cmp dl,4 je @@StandardVGAMode mov [CntColors],gr256Color cmp dl,8 je @@StandardVGAMode mov [CntColors],gr32KColor cmp dl,15 je @@StandardVGAMode mov [CntColors],gr64KColor cmp dl,16 je @@StandardVGAMode mov [CntColors],gr16MColor ; Setup the correct vectors to point to the appropriate bank switching ; routine for the current color mode. @@StandardVGAMode: cmp [SetupSVGA],NOT_VALID je @@SetBanks call [SetupSVGA] ; Setup the SuperVGA @@SetBanks: push si push di mov ax,[WriteBank16Len] mov bx,[WriteBank16] mov cx,[ReadBank16Len] mov dx,[ReadBank16] mov si,[NewPage16] mov di,[NewPage16Len] cmp [CntColors],gr16Color je @@SetVectors mov ax,[WriteBank256Len] mov bx,[WriteBank256] mov cx,[ReadBank256Len] mov dx,[ReadBank256] cmp [CntMode],13h je @@SetVectors ; Standard VGA mode, use 16 color version mov si,[NewPage256] mov di,[NewPage256Len] @@SetVectors: mov [WriteBankLen],ax mov [WriteBank],bx mov [ReadBankLen],cx mov [ReadBank],dx mov [NewPage],si mov [NewPageLen],di pop di pop si @@Done: mov [CntStartX],0 mov [CntStartY],0 mov ax,SUCCESS jmp @@Exit @@ModeSetFailed: mov ax,FAILURE jmp @@Exit ; The mode number was invalid to us, but may make sense to an underlying ; VBE compatible BIOS. Note that we also call the SuperVGA exit routine ; to bring the SuperVGA back into it's default state. @@InvalidMode: cmp [ExitSVGA],NOT_VALID je @@3 call [ExitSVGA] ; Call the SuperVGA exit code @@3: pop bx mov ax,4F02h CallOldBIOS mov [CntMode],-1 ; Flag that mode is unknown to us! @@Exit: pop es pop ds ; Restore value of registers pop di pop si ret ENDP SuperVGASetMode ;---------------------------------------------------------------------------- ; SuperVGAGetMode - Get Current SuperVGA Video Mode ;---------------------------------------------------------------------------- ; ; Function to return the mode number of the current set video mode. If the ; mode is a normal VGA video mode, the normal mode number is returned, ; otherwise the VBE video mode number for the mode is returned. ; ; Exit: AX - VBE status code ; BX - Current video mode ; ;---------------------------------------------------------------------------- PROC SuperVGAGetMode far push si ; Save registers push di push ds push es mov ax,40h mov es,ax xor bx,bx mov bl,[BYTE es:49h] and bl,7Fh cmp bl,13h mov ax,SUCCESS jbe @@VGAMode mov bx,[CntMode] ; VBE Video mode is active, so return it cmp bx,-1 jne @@VGAMode ; The mode was not known to us, so it may be an underlying VBE video mode. mov ax,4F03h CallOldBIOS @@VGAMode: pop es pop ds ; Restore value of registers pop di pop si ret ENDP SuperVGAGetMode ;---------------------------------------------------------------------------- ; SuperVGAVideoState - Save/Restore SuperVGA video state ;---------------------------------------------------------------------------- ; ; Function to save save/restore the SuperVGA video state. This function ; would be very tricky to implement for all supported SuperVGA's if we ; want to save the entire state. In order to do as best as job as possible, ; we save the state of the hardware as much as possible using the normal ; Video BIOS routines, along with the current video BIOS mode number. To ; restore the state we first reset the current video mode, then call the ; BIOS to reset the hardware state, which should work correctly for most ; SuperVGA situations. ; ; Entry: DL - Subfunction number ; 00h - Get state buffer size ; 01h - Save video state ; 02h - Restore video state ; ES:BX -> Video buffer to save state in ; CX - Flags for what to save ; bit 0 - Video hardware state ; bit 1 - Video BIOS state ; bit 2 - Video DAC state ; bit 3 - SuperVGA state ; ; Exit: AX - VBE Status code ; BX - Number of 64 byte blocks needed to save state ; ;---------------------------------------------------------------------------- PROC SuperVGAVideoState far push si ; Save registers push di push ds push es cmp [VBECompliant],0 je @@NoVBE ; Some VBE BIOS'es are stuffed, and return negative values for the ; state size. We check to see if the BIOS functions correctly here, ; using the standard VGA routine if it doesnt. push es push bx push cx push dx xor dl,dl ; Get state buffer size service mov ax,4F04h CallOldBIOS or bx,bx ; Set flags before popping regs pop dx pop cx pop bx pop es js @@NoVBE ; Value was bad, so don't use it... ; Use the underlying VBE BIOS to do this for us, rather than use the ; normal VGA routine which may not save all extended register information. mov ax,4F04h CallOldBIOS jmp @@Exit ; Otherwise use the standard VGA save/restore routine as a substitute. @@NoVBE: mov ah,1Ch ; Save/Restore video state BIOS call mov al,dl ; AL := subfunction number and cl,07h ; Mask out all but normal VGA bits CallOldBIOS cmp al,1Ch mov ax,FAILURE jne @@Exit mov ax,SUCCESS @@Exit: pop es pop ds ; Restore value of registers pop di pop si ret ENDP SuperVGAVideoState ;---------------------------------------------------------------------------- ; SuperVGABankSwitch - CPU Video Memory Control ;---------------------------------------------------------------------------- ; ; Function to switch video banks for the SuperVGA. This function can be ; called as a far function call, rather than through the Int 10h mechanism ; for speed. ; ; Entry: BH - Subfunction number ; 00h - Select video memory window ; 01h - Get video memory window ; BL - Window number ; 00h - Window A ; 01h - Window B ; DX - Window address in video memory (granularity units) ; ; Exit: AX - VBE status code. ; DX - Window address in video memory (when requested) ; ;---------------------------------------------------------------------------- PROC SuperVGABankSwitch far or bh,bh jnz @@Done ; Simply return the current window mov ax,dx ; AX := bank number mov [CurBank],ax ; Save current bank number or bl,bl jnz @@WindowB call [DWORD WriteBank] ; Set new write bank jmp @@Done @@WindowB: cmp [TwoBanks],false je @@Done ; Dual banking not supported call [DWORD ReadBank] ; Set new read bank @@Done: mov dx,[CurBank] ; Return the current bank number mov ax,SUCCESS ret ENDP SuperVGABankSwitch ;---------------------------------------------------------------------------- ; SuperVGAScanlineWidth - Get/Set Logical Scanline Length ;---------------------------------------------------------------------------- ; ; Function to get/set the logical scanline length. This value is specified ; in pixels, but may require rounding to the next available value. The ; actual value set will be returned. ; ; Entry: BL - Subfunction number ; 00h - Set scanline length ; 01h - Get scanline length ; CX - Desired scanline length in pixels ; ; Exit: AX - VBE status code ; BX - Bytes per scanline ; CX - Pixels per scanline ; DX - Maximum number of scanlines ; ;---------------------------------------------------------------------------- PROC SuperVGAScanlineLength far push si ; Save registers push di push ds push es mov ax,[CntColors] or bl,bl jnz @@GetScanlineLength ; We are attempting to set the scanline width for the mode. First we need ; to adjust the value into bytes, and then set the CRTC offset register cmp ax,gr16Color je @@Colors16 cmp ax,gr256Color je @@Colors256 cmp ax,gr32kColor je @@Colors32k cmp ax,gr64kColor je @@Colors32k mov ax,cx shl cx,1 add cx,ax ; CX := bytes per scanline and cx,0FFF8h ; Mask off bottom three bits mov [CurBytesPerLine],cx ; Save BytesPerLine value shr cx,3 ; Shift value for offset register jmp @@SetOffsetReg @@Colors16: shr cx,3 and cx,0FFF0h ; Mask off bottom four bits mov [CurBytesPerLine],cx ; Save BytesPerLine value shr cx,4 ; Shift value for offset register jmp @@SetOffsetReg ; CX := bytes per scanline @@Colors256: and cx,0FFF8h ; Mask off bottom three bits mov [CurBytesPerLine],cx ; Save BytesPerLine value shr cx,3 ; Shift value for offset register jmp @@SetOffsetReg @@Colors32k: shl cx,1 and cx,0FFF8h ; Mask off bottom three bits mov [CurBytesPerLine],cx ; Save BytesPerLine value shr cx,3 ; Shift value for offset register @@SetOffsetReg: mov dx,CRTC mov ah,cl mov al,13h out dx,ax ; Program the CRTC offset value ; Now return the scanline length. We also compute the maximum number of ; scanlines for the entire amount of display memory installed. @@GetScanlineLength: mov ax,[CntMemory] ; AX := amount of memory in k mov dx,ax shl ax,10 ; AX := low order bits of memory shr dx,6 ; DX:AX := memory in bytes mov bx,[CurBytesPerLine] ; BX := bytes per line mov cx,bx ; CX := pixel per scanline div bx mov dx,ax ; DX := number of scanlines mov ax,[CntColors] ; AX := current color mode cmp ax,gr16Color je @@GetColors16 cmp ax,gr256Color je @@Exit cmp ax,gr32kColor je @@GetColors32k cmp ax,gr64kColor je @@GetColors32k mov ax,cx shr cx,1 sub cx,ax ; CX := pixels per scanline jmp @@Exit @@GetColors16: shl cx,3 ; CX := pixels per scanline jmp @@Exit @@GetColors32k: shr cx,1 ; CX := pixels per scanline @@Exit: mov ax,SUCCESS pop es pop ds ; Restore value of registers pop di pop si ret ENDP SuperVGAScanlineLength ;---------------------------------------------------------------------------- ; SuperVGADisplayStart - Get/Set Display Start ;---------------------------------------------------------------------------- ; ; Set the display start address for the current SuperVGA video mode. ; ; Entry: BH - 00h ; BL - Subfunction number ; 00h - Set display start ; 01h - Get display start ; CX - Leftmost displayed pixel in scanline ; DX - First displayed scanline ; ; Exit: CX - Leftmost displayed pixel in scanline ; DX - First displayed scanline ; ;---------------------------------------------------------------------------- PROC SuperVGADisplayStart far mov ax,FAILURE cmp [NewPage],NOT_VALID je @@Failure or bl,bl jnz @@GetDisplayStart ; Set the starting display address. mov [CntStartX],cx ; Save the display starting coordinates mov [CntStartY],dx mov ax,[CurBytesPerLine] mul dx ; DX:AX := y * bytesPerLine mov bx,[CntColors] cmp bx,gr16Color je @@Colors16 cmp bx,gr256Color je @@Colors256 cmp bx,gr32kColor je @@Colors32k cmp bx,gr64kColor je @@Colors32k ; Video mode is a 24 bit video mode add ax,cx ; DX:AX := x + y * bytesPerLine adc dx,0 shl cx,1 add ax,cx ; DX:AX := x * 3 + y * bytesPerLine adc dx,0 shr dx,1 rcr ax,1 shr dx,1 rcr ax,1 ; Adjust to lie on plane boundary jmp @@SetDisplayStart ; Video mode is a 16 color video mode @@Colors16: shr cx,3 add ax,cx ; DX:AX := x/8 + y * bytesPerLine adc dx,0 jmp @@SetDisplayStart ; Video mode is a 256 color video mode @@Colors256: add ax,cx ; DX:AX := x + y * bytesPerLine adc dx,0 shr dx,1 rcr ax,1 shr dx,1 rcr ax,1 ; Adjust to lie on plane boundary jmp @@SetDisplayStart ; Video mode is a 32k color video mode @@Colors32k: shl cx,1 add ax,cx ; DX:AX := x + y * bytesPerLine adc dx,0 shr dx,1 rcr ax,1 shr dx,1 rcr ax,1 ; Adjust to lie on plane boundary @@SetDisplayStart: mov cl,0Ch ; CL := Start Address High register mov ch,ah ; CH := high byte of new address mov bh,al ; BH := low byte of new address mov bl,0Dh ; BL := Start Address Low register mov si,dx ; SI := Bits 16+ for SuperVGA's call [DWORD NewPage] ; Program the start address mov ax,SUCCESS xor bh,bh ; BH must be zero on exit jmp @@Exit @@Failure: mov ax,FAILURE jmp @@Exit @@GetDisplayStart: mov cx,[CntStartX] ; Return saved starting coordinates mov dx,[CntStartY] mov ax,SUCCESS @@Exit: ret ENDP SuperVGADisplayStart ;---------------------------------------------------------------------------- ; SuperVGADACControl - Get/Set video DAC width ;---------------------------------------------------------------------------- ; ; Set the display start address for the current SuperVGA video mode. ; Currently we only support changing the DAC size to 8 bits wide, rather ; than the standard 6 bits wide (however, I have yet to find information ; on how to do this for any video cards :-( The framework is here, all I ; need now it to find the information). ; ; Entry: BH - Desired number of bits per primary ; BL - Subfunction number ; 00h - Set DAC palette width ; 01h - Get DAC palette width ; ; Exit: AX - VBE status code ; BH - Current number of bits per primary ; ;---------------------------------------------------------------------------- PROC SuperVGADACControl far cmp [Set8BitDac],NOT_VALID jne @@NoVBE ; Use our routine if one is supplied cmp [VBECompliant],102h jl @@NoVBE ; Older BIOS, so must try it ourselves mov ax,4F08h ; Call the old VBE 1.2 BIOS instead CallOldBIOS ret @@NoVBE: or bl,bl jnz @@GetDacWidth cmp [Set8BitDac],NOT_VALID je @@Failure ; DAC width is fixed... ; Attempting to set the DAC width. cmp bh,6 je @@Set6Bit call [Set8BitDac] mov [CntDacWidth],8 jmp @@GetDacWidth @@Set6Bit: call [Set6BitDac] mov [CntDacWidth],6 @@GetDacWidth: mov ax,SUCCESS mov bh,[CntDacWidth] ; Currently on VGA DAC's are supported jmp @@Exit @@Failure: mov ax,FAILURE ; DAC width could not be changed @@Exit: ret ENDP SuperVGADACControl ;---------------------------------------------------------------------------- ; ValidateVBEMode Check if a mode is valid and finds index table entry ;---------------------------------------------------------------------------- ; ; Validates that the mode is one of the valid modes for the currently ; installed SuperVGA, and looks up the address of the correct index ; table entry. ; ; Entry: CX - VBE mode number ; ; Exit: CX - VBE mode number ; DS:SI -> Index Table entry for mode ; ; Registers: none ; ;---------------------------------------------------------------------------- PROC ValidateVBEMode near push ax push cs pop ds mov si,offset ModeTable ; DS:SI -> Valid modes table @@ValidLoop: lodsw ; Get next valid mode cmp ax,-1 je @@Invalid ; Mode is invalid to us! cmp ax,cx jne @@ValidLoop ; Not this mode, so continue ; Find the index entry in the mode information table for this mode. mov si,offset IndexTable; DS:SI -> Mode Information table @@ModeLoop: cmp [WORD si],-1 je @@Invalid ; Mode is not in this table cmp [si],cx ; Is this our mode information block? je @@Done ; Yes, so we are done add si,INDEX_ENTRY_SIZE jmp @@ModeLoop @@Invalid: mov si,-1 ; Mode was invalid @@Done: pop ax ret ENDP ValidateVBEMode ;---------------------------------------------------------------------------- ; Buffer area for relocated versions of the bank switching and CRT ; addressing routines. The length of the buffer space here must be equal ; to the largest routine, which so far is the S3 bank switching routines. ;---------------------------------------------------------------------------- WriteBank16Buf db WRITE_BUF_SIZE dup (0) ReadBank16Buf db READ_BUF_SIZE dup (0) WriteBank256Buf db WRITE_BUF_SIZE dup (0) ReadBank256Buf db READ_BUF_SIZE dup (0) NewPage16Buf db PAGE_BUF_SIZE dup (0) NewPage256Buf db PAGE_BUF_SIZE dup (0) SetupBuf db SETUP_BUF_SIZE dup (0) ExitBuf db EXIT_BUF_SIZE dup (0) Set8BitDacBuf db DAC_BUF_SIZE dup (0) Set6BitDacBuf db DAC_BUF_SIZE dup (0) EndResident: ; End of resident code ;---------------------------------------------------------------------------- ; Transient Code. ;---------------------------------------------------------------------------- ASSUME cs:main_TEXT, ds:DGROUP, es:NOTHING INCLUDE "_ati.asm" INCLUDE "_ahead.asm" INCLUDE "_chips.asm" INCLUDE "_everex.asm" INCLUDE "_genoa.asm" INCLUDE "_oak.asm" INCLUDE "_paradis.asm" INCLUDE "_trident.asm" INCLUDE "_video7.asm" INCLUDE "_tseng.asm" INCLUDE "_ncr.asm" INCLUDE "_s3.asm" INCLUDE "_acumos.asm" INCLUDE "_avance.asm" INCLUDE "_mxic.asm" INCLUDE "_primus.asm" INCLUDE "_realtek.asm" INCLUDE "_cirrus.asm" INCLUDE "_tables.asm" ;---------------------------------------------------------------------------- ; bool isLoaded(void) ;---------------------------------------------------------------------------- ; Returns true if the Universal VBE TSR is already loaded in memory. ;---------------------------------------------------------------------------- procstart _isLoaded push ds GetVector 10h ; ES:BX -> Current INT10h vector mov di,bx sub di,offset Int10ISR - offset Signature ; ES:DI -> Signature in loaded TSR push cs pop ds mov si,offset Signature ; DS:SI -> Signature in .COM file mov cx,SigLen ; CX := length of signature string cld mov ax,1 ; Assume already loaded repe cmpsb jcxz @@AlreadyLoaded ; Driver is already loaded! xor ax,ax ; Driver is not loaded @@AlreadyLoaded: pop ds ret procend _isLoaded ;---------------------------------------------------------------------------- ; bool unload(void) ;---------------------------------------------------------------------------- ; Unloads the Universal VESA VBE from memory. This assume it _is_ currently ; installed. ;---------------------------------------------------------------------------- procstart _unload GetVector 10h ; ES:BX -> Current INT10h vector ; Since we know we are already installed, ES:00 will point to the ; start of our code segment, which is where the signature is located. ; We can thus get the old interrupt vector value which resides in memory ; just after the program signature. push es mov dx,[es:OldInt10Seg] mov ds,dx mov dx,[es:OldInt10Off] mov ax,2510h int 21h ; Reset the interrupt vector via DOS pop es ; We can find the segment of our PSP by taking 10h of the value of ES, and ; we then pass this value to DOS to free all memory occupied by the TSR ; (note that we freed the environment block when we went TSR). mov ax,es sub ax,10h mov es,ax ; ES := segment of TSR's PSP mov ah,49h int 21h ; Free memory associated with TSR mov ax,4C00h int 21h ; Terminate the program procend _unload ;---------------------------------------------------------------------------- ; void copyModeInfo(void *IndexTable,int size) ;---------------------------------------------------------------------------- ; Copies the mode table information into the resident portion of the ; driver. ;---------------------------------------------------------------------------- procstart _copyModeInfo ARG pIndexTable:DWORD, tableSize:WORD push bp mov bp,sp push ds push si push di mov ax,[WORD pIndexTable+2] mov ds,ax mov si,[WORD pIndexTable] ; DS:SI -> source index table mov ax,seg IndexTable mov es,ax mov di,offset IndexTable ; ES:DI -> destination index table mov cx,[tableSize] cld rep movsb ; Copy the data pop di pop si pop ds pop bp ret procend _copyModeInfo ;---------------------------------------------------------------------------- ; void copyValidModes(void *validModes,int size) ;---------------------------------------------------------------------------- ; Copies the valid video modes table into the resident portion of the ; driver. ;---------------------------------------------------------------------------- procstart _copyValidModes ARG pValidModes:DWORD, tableSize:WORD push bp mov bp,sp push ds push si push di mov ax,[WORD pValidModes+2] mov ds,ax mov si,[WORD pValidModes] ; DS:SI -> source index table mov ax,seg ModeTable mov es,ax mov di,offset ModeTable ; ES:DI -> destination index table mov cx,[tableSize] cld rep movsb ; Copy the data pop di pop si pop ds pop bp ret procend _copyValidModes ;---------------------------------------------------------------------------- ; void install(int superVGA,int chipID,int memory,int dac,int pageFlip, ; int VBECompliant) ;---------------------------------------------------------------------------- ; ; This routine installs the VBE driver for the specified SuperVGA ; configuration and returns to the main program. ; ; Registers: all ; ;---------------------------------------------------------------------------- procstart _install ARG superVGA:WORD, chipID:WORD, memory:WORD, dac:WORD, \ _pageFlip:WORD, _VBECompliant:WORD push bp mov bp,sp push ds ; Store the values for the SuperVGA configuration. mov ax,[superVGA] mov [CntSuperVGA],ax mov ax,[chipID] mov [CntChipID],ax mov ax,[memory] mov [CntMemory],ax mov ax,[dac] mov [CntDac],ax mov ax,[_VBECompliant] mov [VBECompliant],ax ; Store the memory size in the VBE mode information block mov ax,[memory] shr ax,6 ; AX := memory in 64k lots mov [VBEMemSize],al ; Save the value for later ; Setup the SuperVGA tables and initialise the SuperVGA. Determine if ; dual banking is supported, modifying the video mode information table if ; not. call SetupSuperVGA ; Setup SuperVGA tables ; Copy the bank switching routines into the appropriate buffers within ; the resident code and re-vector to point to them. We also check to make ; sure they fit in the buffers, failing to install if they don't. push cs pop ds push cs pop es mov si,[WriteBank16] ; DS:SI -> write bank 16 routine mov di,offset WriteBank16Buf ; ES:DI -> write bank 16 buffer mov cx,[WriteBank16Len] cmp cx,WRITE_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[ReadBank16] ; DS:SI -> read bank 16 routine mov di,offset ReadBank16Buf ; ES:DI -> read bank 16 buffer mov cx,[ReadBank16Len] cmp cx,READ_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[WriteBank256] ; DS:SI -> write bank 256 routine mov di,offset WriteBank256Buf ; ES:DI -> write bank 256 buffer mov cx,[WriteBank256Len] cmp cx,WRITE_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[ReadBank256] ; DS:SI -> read bank 256 routine mov di,offset ReadBank256Buf ; ES:DI -> read bank 256 buffer mov cx,[ReadBank256Len] cmp cx,READ_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[NewPage16] ; DS:SI -> new page routine mov di,offset NewPage16Buf ; ES:DI -> new page buffer mov cx,[NewPage16Len] cmp cx,PAGE_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[NewPage256] ; DS:SI -> new page routine mov di,offset NewPage256Buf ; ES:DI -> new page buffer mov cx,[NewPage256Len] cmp cx,PAGE_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[SetupSVGA] ; DS:SI -> new setup routine mov di,offset SetupBuf ; ES:DI -> new setup buffer mov cx,[SetupSVGALen] cmp cx,SETUP_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[ExitSVGA] ; DS:SI -> new exit routine mov di,offset ExitBuf ; ES:DI -> new exit buffer mov cx,[ExitSVGALen] cmp cx,EXIT_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[Set8BitDac] ; DS:SI -> new 8 bit DAC routine mov di,offset ExitBuf ; ES:DI -> new 8 bit DAC buffer mov cx,[Set8BitDacLen] cmp cx,DAC_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine mov si,[Set6BitDac] ; DS:SI -> new 6 bit DAC routine mov di,offset ExitBuf ; ES:DI -> new 6 bit DAC buffer mov cx,[Set6BitDacLen] cmp cx,DAC_BUF_SIZE jg @@FailInstall ; Ensure routine will fit rep movsb ; Copy the routine ifndef TESTING ; Revector to use the re-located versions of the routines. This will only ; be done when testing is not on, so you can still debug the routines. mov [WriteBank16],offset WriteBank16Buf mov [ReadBank16],offset ReadBank16Buf mov [WriteBank256],offset WriteBank256Buf mov [ReadBank256],offset ReadBank256Buf cmp [NewPage16],NOT_VALID je @@1 mov [NewPage16],offset NewPage16Buf mov [NewPage256],offset NewPage256Buf @@1: cmp [SetupSVGA],NOT_VALID je @@2 mov [SetupSVGA],offset SetupBuf @@2: cmp [ExitSVGA],NOT_VALID je @@3 mov [ExitSVGA],offset ExitBuf @@3: cmp [Set8BitDac],NOT_VALID je @@4 mov [Set8BitDac],offset Set8BitDacBuf mov [Set6BitDac],offset Set6BitDacBuf endif @@4: cmp [TwoBanks],true je @@DualBank mov [WinBAttr],0 ; Remove support for second video bank @@DualBank: call HookVectors ; Hook interrupt vectors mov ax,true ; Installed correctly pop ds pop bp ret @@FailInstall: mov ax,false ; Could not install!!! pop ds ; Restore DS pop bp ret procend _install ;---------------------------------------------------------------------------- ; void goTSR(void) ;---------------------------------------------------------------------------- ; ; This routine exists to the operating system leaving the required ; code resident in memory. ; ; If we are in testing mode, the routine does not go TSR but simply ; calls the 'C' testing routine, unhooks the interrupts and exits. ; ; Registers: all ; ;---------------------------------------------------------------------------- procstart _goTSR ifndef TESTING ; Now setup to go TSR with resident code. mov ax,[__psp] mov es,ax xor ax,ax xchg ax,[es:2Ch] ; AX := seg of environment block mov es,ax ; ES := seg of environment block mov ah,49h int 21h ; Free the environment block mov ah,31h mov al,[BYTE CntSuperVGA] ; Return SuperVGA id as result code mov dx,offset EndResident add dx,PSPSize + 15 ; PSP is always resident!! shr dx,4 int 21h ; Go TSR! else ; Call the C testing routine, unhook vectors and quit. call _testISR ; Call the test routine call UnhookVectors ; Unhook vectors ret endif procend _goTSR ;---------------------------------------------------------------------------- ; HookVectors - Hook into the interrupt vectors that we require. ;---------------------------------------------------------------------------- ; ; Saves the value of the old interrupt vectors that we require, and ; install's hooks to our code for the vectors. ; ; Registers: all ; ;---------------------------------------------------------------------------- PROC HookVectors near ; Save old interrupt vectors GetVector 10h mov [cs:OldInt10Off],bx mov [cs:OldInt10Seg],es ; Insert our interrupt vectors into vector table SetVector 10h, Int10ISR ret ENDP HookVectors ;---------------------------------------------------------------------------- ; UnhookVectors - Unhook from all interrupt vectors that we own. ;---------------------------------------------------------------------------- ; ; Restores the interrupt vector table to what it was before we installed ; ourselves. ; ; Registers: all ; ;---------------------------------------------------------------------------- PROC UnhookVectors push ds mov dx,[OldInt10Seg] mov ds,dx mov dx,[OldInt10Off] mov ah,25h mov al,10h int 21h pop ds ret ENDP UnhookVectors endcodeseg main END