;**************************************************************************** ;* ;* SuperVGA Test Library ;* ;* Copyright (C) 1993 Kendall Bennett. ;* All rights reserved. ;* ;* Filename: $RCSfile: svga.asm $ ;* Version: $Revision: 1.1 $ ;* ;* Language: 80386 Assembler ;* Environment: IBM PC (MS DOS) ;* ;* Description: Assembly language support routines for the SuperVGA test ;* library. ;* ;* $Id: svga.asm 1.1 1993/09/19 02:05:28 kjb release $ ;* ;* Revision History: ;* ----------------- ;* ;* $Log: svga.asm $ ;* Revision 1.1 1993/09/19 02:05:28 kjb ;* Initial revision ;* ;**************************************************************************** IDEAL JUMPS P386 ; Use 386 instructions MODEL large CRTC EQU 3D4h ; Port of CRTC registers VGABufferSeg EQU 0A000h ; Segment of VGA display memory DATASEG COMM _maxx:WORD COMM _maxy:WORD COMM _maxcolor:DWORD COMM _bytesperline:WORD COMM _pagesize:DWORD COMM _curBank:WORD COMM _bankSwitch:DWORD COMM _extendedflipping:WORD COMM _bankAdjust:WORD COMM _writeBank:DWORD; Relocated write bank routine COMM _readBank:DWORD ; Relocated read bank routine COMM _pageFlip:DWORD ; Relocated page flip routine OriginOffset dw 0 ; Starting offset within bank BankOffset dw 0 ; Starting bank in video memory CODESEG MACRO procstart name ; Set up model independant proc PROC name PUBLIC name ENDM MACRO procend name ; End procedure macro ENDP name ENDM ;---------------------------------------------------------------------------- ; void putPixel16(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart _putPixel16 ARG x:WORD, y:WORD, color:DWORD push bp ; Set up stack frame mov bp,sp ; Compute the pixel's address in video buffer mov ax,[y] mov bx,[x] mul [_bytesPerLine] ; DX:AX := y * BytesPerLine mov cl,bl ; CL := low-order byte of x shr bx,3 ; BX := x/8 add bx,ax adc dx,0 ; DX:BX := y*BytesPerLine + x/8 add bx,[OriginOffset] ; DX:BX := byte offset in video buffer adc dx,[BankOffset] cmp dl,[BYTE _curBank] je @@NoChange mov ax,dx call setBank @@NoChange: mov ax,VGABufferSeg mov es,ax ; ES:BX := byte address of pixel mov ah,1 ; AH := unshifted bit mask and cl,7 ; CL := x & 7 xor cl,7 ; CL := # bits to shift left ; set Graphics Controller Bit Mask register shl ah,cl ; AH := bit mask in proper postion mov dx,3CEh ; GC address register port mov al,8 ; AL := Bit Mask Register number out dx,ax ; set Graphics Controller Mode register mov ax,0205h ; AL := Mode register number ; AH := Write mode 2 (bits 0,1) ; Read mode 0 (bit 3) out dx,ax ; set data rotate/Function Select register mov ax,3 ; AL := Data Rotate/Func select reg # out dx,ax ; set the pixel value mov al,[es:bx] ; latch one byte from each bit plane mov al,[BYTE color] ; AL := pixel value mov [es:bx],al ; update all bit planes ; restore default Graphics Controller registers mov ax,0FF08h ; default bit mask out dx,ax mov ax,0005 ; default mode register out dx,ax mov ax,0003 ; default function select out dx,ax pop bp ret procend _putPixel16 ;---------------------------------------------------------------------------- ; void putPixel256(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart _putPixel256 ARG x:WORD, y:WORD, color:DWORD push bp ; Set up stack frame mov bp,sp mov ax,[y] mul [_bytesperline] add ax,[x] adc dx,0 ; DX:AX := y * BytesPerLine + x add ax,[OriginOffset] adc dl,[BYTE BankOffset]; DL := bank number mov bx,ax ; BX := Offset in buffer cmp dl,[BYTE _curBank] je @@NoChange mov ax,dx call setBank @@NoChange: mov ax,VGABufferSeg mov es,ax ; ES:BX := byte address of pixel mov al,[BYTE color] mov [es:bx],al ; Replace the pixel pop bp ret procend _putPixel256 ;---------------------------------------------------------------------------- ; void putPixel32k(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart _putPixel32k ARG x:WORD, y:WORD, color:DWORD push bp ; Set up stack frame mov bp,sp mov ax,[y] mul [_bytesperline] mov bx,[x] shl bx,1 add ax,bx adc dx,0 ; DX:AX := y * BytesPerLine + x * 2 add ax,[OriginOffset] adc dl,[BYTE BankOffset]; DL := bank number mov bx,ax ; BX := Offset in buffer cmp dl,[BYTE _curBank] je @@NoChange mov al,dl call setBank @@NoChange: mov ax,VGABufferSeg mov es,ax ; ES:BX := byte address of pixel mov ax,[WORD color] mov [es:bx],ax ; Replace the pixel pop bp ret procend _putPixel32k ;---------------------------------------------------------------------------- ; void putPixel64k(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart _putPixel64k ARG x:WORD, y:WORD, color:DWORD push bp ; Set up stack frame mov bp,sp mov ax,[y] mul [_bytesperline] mov bx,[x] shl bx,1 add ax,bx adc dx,0 ; DX:AX := y * BytesPerLine + x * 2 add ax,[OriginOffset] adc dl,[BYTE BankOffset]; DL := bank number mov bx,ax ; BX := Offset in buffer cmp dl,[BYTE _curBank] je @@NoChange mov al,dl call setBank @@NoChange: mov ax,VGABufferSeg mov es,ax ; ES:BX := byte address of pixel mov ax,[WORD color] mov [es:bx],ax ; Replace the pixel pop bp ret procend _putPixel64k ;---------------------------------------------------------------------------- ; void putPixel16m(int x,int y,long color) ;---------------------------------------------------------------------------- ; Routine sets the value of a pixel in native VGA graphics modes. ; ; Entry: x - X coordinate of pixel to draw ; y - Y coordinate of pixel to draw ; color - Color of pixel to draw ; ;---------------------------------------------------------------------------- procstart _putPixel16m ARG x:WORD, y:WORD, color:DWORD push bp ; Set up stack frame mov bp,sp mov ax,[y] mul [_bytesperline] mov bx,[x] add ax,bx adc dx,0 shl bx,1 add ax,bx adc dx,0 ; DX:AX := y * BytesPerLine + x * 3 add ax,[OriginOffset] adc dl,[BYTE BankOffset]; DL := bank number mov bx,ax ; BX := Offset in buffer cmp dl,[BYTE _curBank] je @@NoChange mov al,dl call setBank @@NoChange: mov ax,VGABufferSeg mov es,ax ; ES:BX := byte address of pixel mov al,[BYTE color] mov [es:bx],al ; Replace the first byte cmp bx,0FFFFh jne @@NotSplit1 ; Arrghh!! We have a case where a single pixel can be split across a ; bank boundary, if the bytes per line value is 1920. This can cause the ; machine to hang (and produce strange pixels). inc dl mov al,dl call setBank ; Change video banks @@NotSplit1: mov al,[BYTE color+1] mov [es:bx+1],al ; Replace the middle cmp bx,0FFFEh jne @@NotSplit2 inc dl mov al,dl call setBank ; Change video banks @@NotSplit2: mov al,[BYTE color+2] mov [es:bx+2],al ; Replace the last byte pop bp ret procend _putPixel16m ;---------------------------------------------------------------------------- ; void clear16(void) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Works even if the display contains more than ; one bank, so will work for 1024x768 and 1280x1024 video modes. ;---------------------------------------------------------------------------- procstart _clear16 push bp ; Set up stack frame mov bp,sp push si ; Save registers push di ; Setup graphics controller mov dx,3CEh ; DX := Graphics Controller I/O port mov ah,0 ; AH := Background color xor al,al ; AL := 0 (Set/Reset register number) out dx,ax ; load set/reset register mov ax,0F01h ; AH := 1111b (mask for Enable set/reset) ; AL := 1 (enable Set/reset reg number) out dx,ax ; load enable set/reset reg mov ax,[_maxy] inc ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,VGABufferSeg mov es,ax mov di,[OriginOffset] ; ES:DI -> video buffer mov ax,[BankOffset] ; AX := starting bank number cld ; Moves go up in memory or dh,dh ; More than one bank to fill? jz @@SingleBank ; No, only fill a single bank ; Fill all of the full 64k banks first @@OuterLoop: call setBank mov cx,4000h ; Need to set 4000h double words per bank rep stosd inc al dec dh jnz @@OuterLoop ; Now fill the last partial bank @@SingleBank: call setBank mov cx,bx shr cx,2 ; CX := number of double words to set rep stosd ; Restore graphics controller mov dx,3CEh ; DX := Graphics Controller I/O port xor ax,ax ; AH := 0, AL := 0 out dx,ax ; Restore default Set/Reset register inc ax ; AH := 0, AL := 1 out dx,ax ; Restore enable Set/Reset register pop di pop si pop bp ret procend _clear16 ;---------------------------------------------------------------------------- ; void clear256(void) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Assumes pages begin on bank boundaries ; for simplicity of coding. ;---------------------------------------------------------------------------- procstart _clear256 push di mov ax,[_maxy] inc ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,VGABufferSeg mov es,ax mov di,[OriginOffset] ; ES:DI -> video buffer mov dl,[BYTE BankOffset]; DL := starting bank number cld ; Moves go up in memory or dh,dh ; More than one bank to fill? jz @@SingleBank ; No, only fill a single bank ; Fill all of the full 64k banks first @@OuterLoop: mov al,dl call setBank xor eax,eax ; Clear to black mov cx,4000h ; Need to set 4000h double words per bank rep stosd inc dl dec dh jnz @@OuterLoop ; Now fill the last partial bank @@SingleBank: mov al,dl call setBank xor eax,eax ; Clear to black mov cx,bx shr cx,2 ; CX := number of double words to set rep stosd pop di ret procend _clear256 ;---------------------------------------------------------------------------- ; void clear32k(void) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Assumes pages begin on bank boundaries ; for simplicity of coding. ;---------------------------------------------------------------------------- procstart _clear32k push di mov ax,[_maxy] inc ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,VGABufferSeg mov es,ax mov di,[OriginOffset] ; ES:DI -> video buffer mov dl,[BYTE BankOffset]; DL := starting bank number cld ; Moves go up in memory ; Fill all of the full 64k banks first @@OuterLoop: mov al,dl call setBank xor eax,eax ; Clear to black mov cx,4000h ; Need to set 4000h double words per bank rep stosd inc dl dec dh jnz @@OuterLoop ; Now fill the last partial bank mov al,dl call setBank xor eax,eax ; Clear to black mov cx,bx shr cx,2 ; CX := number of double words to set rep stosd pop di ret procend _clear32k ;---------------------------------------------------------------------------- ; void clear64k(void) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Assumes pages begin on bank boundaries ; for simplicity of coding. ;---------------------------------------------------------------------------- procstart _clear64k push di mov ax,[_maxy] inc ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,VGABufferSeg mov es,ax mov di,[OriginOffset] ; ES:DI -> video buffer mov dl,[BYTE BankOffset]; DL := starting bank number cld ; Moves go up in memory ; Fill all of the full 64k banks first @@OuterLoop: mov al,dl call setBank xor eax,eax ; Clear to black mov cx,4000h ; Need to set 4000h double words per bank rep stosd inc dl dec dh jnz @@OuterLoop ; Now fill the last partial bank mov al,dl call setBank xor eax,eax ; Clear to black mov cx,bx shr cx,2 ; CX := number of double words to set rep stosd pop di ret procend _clear64k ;---------------------------------------------------------------------------- ; void clear16m(void) ;---------------------------------------------------------------------------- ; Routine to clear the screen. Assumes pages begin on bank boundaries ; for simplicity of coding. ;---------------------------------------------------------------------------- procstart _clear16m push di mov ax,[_maxy] inc ax mul [_bytesperline] ; DX:AX := number of bytes to fill mov bx,ax ; BX := bytes in last bank to fill mov dh,dl ; DH := number of full banks to fill mov ax,VGABufferSeg mov es,ax xor di,di ; ES:DI -> video buffer mov dl,[BYTE BankOffset]; DL := starting bank number cld ; Moves go up in memory ; Fill all of the full 64k banks first @@OuterLoop: mov al,dl call setBank xor eax,eax ; Clear to black mov cx,4000h ; Need to set 4000h double words per bank rep stosd inc dl dec dh jnz @@OuterLoop ; Now fill the last partial bank mov al,dl call setBank xor eax,eax ; Clear to black mov cx,bx shr cx,2 ; CX := number of double words to set rep stosd pop di ret procend _clear16m ;---------------------------------------------------------------------------- ; void _copyTest16(void) ;---------------------------------------------------------------------------- ; Routine to copy the top half of video memory to the bottom half of ; video memory. To ensure that we a moving across a bank boundary in ; 16 color modes, we copy the data to the second video page. ;---------------------------------------------------------------------------- procstart __copyTest16 push si ; Save registers push di push ds mov ax,[_maxy] inc ax shr ax,1 ; AX := (Yres+1) / 2 mul [_bytesperline] mov cx,ax ; CX := Number of bytes to move ; Set up graphics controller mov dx,3CEh ; DX := Graphics Controller address port mov ax,0105h ; AH := 1 (read mode 0, write mode 1) ; AL := 5 (Mode register number) out dx,ax ; Set up mode mov di,[WORD _pagesize] ; ES:DI := offset into destination buffer mov ax,[WORD _pagesize+2] add di,cx adc al,0 call setBank ; Set the read/write bank number xor si,si ; DS:SI := offset into source buffer xor ax,ax call setReadBank ; Set the read bank number mov ax,VGABufferSeg mov ds,ax ; DS:SI -> source buffer mov es,ax ; ES:DI -> destination buffer cld ; Moves go up in memory rep movsb ; Move all data in bank FAST! ; Restore default graphics controller state mov ax,0005h ; default mode register value out dx,ax pop ds pop di pop si ret procend __copyTest16 ;---------------------------------------------------------------------------- ; void _copyTest256(void) ;---------------------------------------------------------------------------- ; Routine to copy the top half of video memory to the bottom half of ; video memory, to test moving data across bank boundaries using separate ; read/write banks. To simplify the coding we move the first 100 scan ; lines down to start at scanline 205. This ensure allows us to move data ; from bank 0 to bank 2 in 640x??? display modes. ;---------------------------------------------------------------------------- procstart __copyTest256 push si ; Save registers push di push ds mov ax,100 mul [_bytesperline] mov cx,ax ; CX := Number of bytes to move shr cx,1 ; CX := Number of words to move mov ax,205 mul [_bytesperline] mov di,ax ; DI := offset into destination bank mov al,dl call setBank ; Set the read/write bank number xor si,si ; DS:SI := offset into source buffer xor al,al call setReadBank ; Set the read bank number mov ax,VGABufferSeg mov ds,ax ; DS:SI -> source buffer mov es,ax ; ES:DI -> destination buffer cld ; Moves go up in memory rep movsw ; Move all data in bank FAST! pop ds pop di pop si ret procend __copyTest256 ;---------------------------------------------------------------------------- ; void setActivePage(int which) ;---------------------------------------------------------------------------- ; Routine to set the video page for active output. ; ; Entry: page - Page number of page to use ; ;---------------------------------------------------------------------------- procstart _setActivePage ARG which:WORD push bp ; Set up stack frame mov bp,sp ; Calculate 18 bit address of page in video memory xor eax,eax mov ax,[which] ; EAX := page number mul [_pagesize] ; EDX:EAX := result mov [OriginOffset],ax ; Save video buffer offset shr eax,16 mov [BankOffset],ax ; Save video bank offset pop bp ret procend _setActivePage ;---------------------------------------------------------------------------- ; void setVisualPage(int which) ;---------------------------------------------------------------------------- ; Routine to set the visible video page. ; ; Entry: page - Page number of page to use ; ;---------------------------------------------------------------------------- procstart _setVisualPage ARG which:WORD push bp ; Set up stack frame mov bp,sp push si ; Calculate 18 bit address of page in video memory xor eax,eax mov ax,[which] ; EAX := page number mul [_pagesize] ; EAX := starting address in memory mov edx,eax shr edx,16 ; DX:AX := starting address in memory cmp [_extendedflipping],0 je @@VGAFlip ; We have no extended page flipping cmp [WORD _pageFlip+2],0 je @@VBEFlip ; Set up to call the relocated version of the page flip routine loaded ; on the heap. This allows us to bypass the int10h interface for speed ; (well, not much different in real mode, but in protected mode this ; will be significant). cmp [WORD _maxColor],15 je @@Colors16 shr eax,2 ; Adjust to lie on plane boundary mov edx,eax shr edx,16 ; DX:AX := starting address in memory @@Colors16: push dx ; Save top bits of address ; Wait for display enable to be active (active low), to be sure that ; both halves of the start address will take place in one frame. We ; preload a few values here to save time after the DE has been ; detected. 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 dx,03DAh ; DX := video status port @@WaitDE: in al,dx test al,1 jnz @@WaitDE ; Wait for Display Enable cli pop si ; SI := Bits 16+ for SuperVGA's call [_pageFlip] ; Program the start address sti jmp @@Done @@VBEFlip: div [_bytesperline] ; AX := starting scanline, ; DX := starting byte mov cx,dx cmp [WORD _maxcolor],0Fh je @@16Color cmp [WORD _maxcolor],0FFh je @@SetIt cmp [WORD _maxcolor+2],0FFh je @@16MColor shr cx,1 ; CX := starting pixel in buffer jmp @@SetIt @@16Color: shl cx,3 ; CX := starting pixel in buffer jmp @@SetIt @@16MColor: xor dx,dx mov ax,cx mov cx,3 div cx mov cx,ax ; CX := starting pixel in buffer @@SetIt: mov bx,ax ; BX := starting scanline in buffer ; Wait for display enable to be active (active low), to be sure that ; both halves of the start address will take place in one frame. mov dx,03DAh ; DX := video status port @@WaitDEVBE: in al,dx test al,1 jnz @@WaitDEVBE ; Wait for Display Enable mov ax,04F07h mov dx,bx ; DX := starting scanline number xor bx,bx ; BX := 0 - set display start int 10h ; Set the display start address jmp @@Done @@VGAFlip: mov bx,ax ; BX := bottom 16 bits of address ; Wait for display enable to be active (active low), to be sure that ; both halves of the start address will take place in one frame. We ; preload a few values here to save time after the DE has been ; detected. mov cl,0Ch ; CL := Start Address High register mov ch,bh ; CH := high byte of new address mov bh,bl ; BH := low byte of new address mov bl,0Dh ; BL := Start Address Low register mov dx,03DAh ; DX := video status port @@WaitDEVGA: in al,dx test al,1 jnz @@WaitDEVGA ; Wait for Display Enable cli mov dx,03D4h ; DX := CRTC I/O port (3D4h) mov ax,bx out dx,ax mov ax,cx out dx,ax sti ; Now wait for the start of the vertical sync, to ensure that the old ; page will be invisible before anything is drawn on it. @@Done: mov dx,03DAh ; DX := video status port @@WaitStartVert: in al,dx ; Wait for start of vertical retrace test al,8 jz @@WaitStartVert @@Exit: pop si pop bp ret procend _setVisualPage ;---------------------------------------------------------------------------- ; setBank Sets the read/write bank from assembly language ;---------------------------------------------------------------------------- ; ; Entry: AX - New read/write bank number ; ; Exit: AX - New read/write bank number ; ; Registers: All preserved! ; ;---------------------------------------------------------------------------- procstart setBank mov [_curBank],ax ; Save current write bank number cmp [WORD _writeBank+2],0 je @@VESABank call [_writeBank] ; Call relocated version ret @@VESABank: push ax push bx push dx mul [_bankAdjust] ; Adjust to VESA granularity push ax mov dx,ax ; DX := bank number xor bx,bx ; BX := select window A call [_bankSwitch] ; Set write window ; Note that some VESA BIOSes and TSR's set the first window to be ; write only and the second window to be read only, so we need to set both ; windows for most common operations to the same value. The Universal ; VESA VBE sets both the read and write banks to the same value for ; Window A, and changed the read bank only for Window B, hence the second ; call is _not_ required when the Universal VESA VBE is installed. You can ; determine what the window does by looking at the WindowAAttributes in ; the SuperVGAInfo block returned by function 00h. You could use this ; information to optimise bank switching when using faster VBE's like ; the Universal VESA VBE (but I have no bothered to do that here). pop dx inc bx call [_bankSwitch] ; Set read window pop dx pop bx pop ax ret procend setBank ;---------------------------------------------------------------------------- ; setReadBank Sets the read bank from assembly language ;---------------------------------------------------------------------------- ; ; Entry: AX - New read bank number ; ; Exit: AX - New read bank number ; ; Registers: All preserved! ; ;---------------------------------------------------------------------------- procstart setReadBank mov [_curBank],-1 ; Ensure banking will be re-loaded cmp [WORD _readBank+2],0 je @@VESABank call [_readBank] ; Call relocated version ret @@VESABank: push ax push bx push dx mov dx,ax ; DX := bank number mov bx,1 ; BX := select window B call [_bankSwitch] pop dx pop bx pop ax ret procend setReadBank ;---------------------------------------------------------------------------- ; void setBank(int bank) ;---------------------------------------------------------------------------- ; Sets the new read/write bank number from C ;---------------------------------------------------------------------------- procstart _setBank ARG bank:WORD push bp mov bp,sp mov ax,[bank] call setBank pop bp ret procend _setBank ;---------------------------------------------------------------------------- ; void setReadBank(int bank) ;---------------------------------------------------------------------------- ; Sets the new reading bank number from C ;---------------------------------------------------------------------------- procstart _setReadBank ARG bank:WORD push bp mov bp,sp mov ax,[bank] call setReadBank pop bp ret procend _setReadBank ;---------------------------------------------------------------------------- ; void *getFontVec(void) ;---------------------------------------------------------------------------- ; Gets a pointer to the currently installed bitmap font from the BIOS. ;---------------------------------------------------------------------------- procstart _getFontVec push bp mov ax,1130h mov bx,0600h int 10h mov dx,es mov ax,bp ; DX:AX -> installed font pop bp ret procend _getFontVec END