// ============================================================================================ // // Copyright (C) 2002 Jeroen Janssen // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA // // ============================================================================================ // // This VBE is part of the VGA Bios specific to the plex86/bochs Emulated VGA card. // You can NOT drive any physical vga card with it. // // ============================================================================================ // // This VBE Bios is based on information taken from : // - VESA BIOS EXTENSION (VBE) Core Functions Standard Version 3.0 located at www.vesa.org // // ============================================================================================ // defines available // enable LFB support #define VBE_HAVE_LFB // disable VESA/VBE2 check in vbe info //#define VBE2_NO_VESA_CHECK // dynamicly generate a mode_info list #define DYN_LIST #include "vbe.h" #include "vbetables.h" // The current OEM Software Revision of this VBE Bios #define VBE_OEM_SOFTWARE_REV 0x0002; extern char vbebios_copyright; extern char vbebios_vendor_name; extern char vbebios_product_name; extern char vbebios_product_revision; #ifndef DYN_LIST extern Bit16u vbebios_mode_list; #endif ASM_START // FIXME: 'merge' these (c) etc strings with the vgabios.c strings? _vbebios_copyright: .ascii "Bochs/Plex86 VBE(C) 2003 http://savannah.nongnu.org/projects/vgabios/" .byte 0x00 _vbebios_vendor_name: .ascii "Bochs/Plex86 Developers" .byte 0x00 _vbebios_product_name: .ascii "Bochs/Plex86 VBE Adapter" .byte 0x00 _vbebios_product_revision: .ascii "$Id: vbe.c,v 1.1 2007/11/29 20:26:38 pdinda Exp $" .byte 0x00 _vbebios_info_string: .ascii "Bochs VBE Display Adapter enabled" .byte 0x0a,0x0d .byte 0x0a,0x0d .byte 0x00 _no_vbebios_info_string: .ascii "NO Bochs VBE Support available!" .byte 0x0a,0x0d .byte 0x0a,0x0d .byte 0x00 #if defined(USE_BX_INFO) || defined(DEBUG) msg_vbe_init: .ascii "VBE Bios $Id: vbe.c,v 1.1 2007/11/29 20:26:38 pdinda Exp $" .byte 0x0a,0x0d, 0x00 #endif #ifndef DYN_LIST // FIXME: for each new mode add a statement here // at least until dynamic list creation is working _vbebios_mode_list: .word VBE_VESA_MODE_640X400X8 .word VBE_VESA_MODE_640X480X8 .word VBE_VESA_MODE_800X600X4 .word VBE_VESA_MODE_800X600X8 .word VBE_VESA_MODE_1024X768X8 .word VBE_VESA_MODE_640X480X1555 .word VBE_VESA_MODE_640X480X565 .word VBE_VESA_MODE_640X480X888 .word VBE_VESA_MODE_800X600X1555 .word VBE_VESA_MODE_800X600X565 .word VBE_VESA_MODE_800X600X888 .word VBE_VESA_MODE_1024X768X1555 .word VBE_VESA_MODE_1024X768X565 .word VBE_VESA_MODE_1024X768X888 .word VBE_OWN_MODE_640X480X8888 .word VBE_OWN_MODE_800X600X8888 .word VBE_OWN_MODE_1024X768X8888 .word VBE_OWN_MODE_320X200X8 .word VBE_VESA_MODE_END_OF_LIST #endif ; DISPI ioport functions dispi_get_id: push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_ID out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx pop dx ret dispi_set_id: push dx push ax mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_ID out dx, ax pop ax mov dx, # VBE_DISPI_IOPORT_DATA out dx, ax pop dx ret ASM_END static void dispi_set_xres(xres) Bit16u xres; { ASM_START push bp mov bp, sp push ax push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_XRES out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA mov ax, 4[bp] ; xres out dx, ax push ax mov dx, #0x03d4 mov ax, #0x0011 out dx, ax mov dx, #0x03d4 pop ax push ax shr ax, #3 dec ax mov ah, al mov al, #0x01 out dx, ax pop ax call vga_set_virt_width pop dx pop ax pop bp ASM_END } static void dispi_set_yres(yres) Bit16u yres; { outw(VBE_DISPI_IOPORT_INDEX,VBE_DISPI_INDEX_YRES); outw(VBE_DISPI_IOPORT_DATA,yres); } static void dispi_set_bpp(bpp) Bit16u bpp; { outw(VBE_DISPI_IOPORT_INDEX,VBE_DISPI_INDEX_BPP); outw(VBE_DISPI_IOPORT_DATA,bpp); } ASM_START ; AL = bits per pixel / AH = bytes per pixel dispi_get_bpp: push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_BPP out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx mov ah, al shr ah, 3 test al, #0x07 jz get_bpp_noinc inc ah get_bpp_noinc: pop dx ret _dispi_get_max_bpp: push dx push bx call dispi_get_enable mov bx, ax or ax, # VBE_DISPI_GETCAPS call _dispi_set_enable mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_BPP out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx push ax mov ax, bx call _dispi_set_enable pop ax pop bx pop dx ret _dispi_set_enable: push dx push ax mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_ENABLE out dx, ax pop ax mov dx, # VBE_DISPI_IOPORT_DATA out dx, ax pop dx ret dispi_get_enable: push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_ENABLE out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx pop dx ret _dispi_set_bank: push dx push ax mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_BANK out dx, ax pop ax mov dx, # VBE_DISPI_IOPORT_DATA out dx, ax pop dx ret dispi_get_bank: push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_BANK out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx pop dx ret ASM_END static void dispi_set_bank_farcall() { ASM_START cmp bx,#0x0100 je dispi_set_bank_farcall_get or bx,bx jnz dispi_set_bank_farcall_error push dx mov ax,# VBE_DISPI_INDEX_BANK mov dx,# VBE_DISPI_IOPORT_INDEX out dx,ax pop ax mov dx,# VBE_DISPI_IOPORT_DATA out dx,ax retf dispi_set_bank_farcall_get: mov ax,# VBE_DISPI_INDEX_BANK mov dx,# VBE_DISPI_IOPORT_INDEX out dx,ax mov dx,# VBE_DISPI_IOPORT_DATA in ax,dx mov dx,ax retf dispi_set_bank_farcall_error: mov ax,#0x014F retf ASM_END } ASM_START dispi_set_x_offset: push dx push ax mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_X_OFFSET out dx, ax pop ax mov dx, # VBE_DISPI_IOPORT_DATA out dx, ax pop dx ret dispi_get_x_offset: push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_X_OFFSET out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx pop dx ret dispi_set_y_offset: push dx push ax mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_Y_OFFSET out dx, ax pop ax mov dx, # VBE_DISPI_IOPORT_DATA out dx, ax pop dx ret dispi_get_y_offset: push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_Y_OFFSET out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx pop dx ret vga_set_virt_width: push ax push bx push dx mov bx, ax call dispi_get_bpp cmp al, #0x04 ja set_width_svga shr bx, #2 set_width_svga: shr bx, #2 mov dx, #0x03d4 mov ah, bl mov al, #0x13 out dx, ax pop dx pop bx pop ax ret dispi_set_virt_width: call vga_set_virt_width push dx push ax mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_VIRT_WIDTH out dx, ax pop ax mov dx, # VBE_DISPI_IOPORT_DATA out dx, ax pop dx ret dispi_get_virt_width: push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_VIRT_WIDTH out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx pop dx ret dispi_get_virt_height: push dx mov dx, # VBE_DISPI_IOPORT_INDEX mov ax, # VBE_DISPI_INDEX_VIRT_HEIGHT out dx, ax mov dx, # VBE_DISPI_IOPORT_DATA in ax, dx pop dx ret ASM_END // ModeInfo helper function static ModeInfoListItem* mode_info_find_mode(mode, using_lfb) Bit16u mode; Boolean using_lfb; { ModeInfoListItem *cur_info=&mode_info_list; while (cur_info->mode != VBE_VESA_MODE_END_OF_LIST) { if (cur_info->mode == mode) { if (!using_lfb) { return cur_info; } else if (cur_info->info.ModeAttributes & VBE_MODE_ATTRIBUTE_LINEAR_FRAME_BUFFER_MODE) { return cur_info; } else { cur_info++; } } else { cur_info++; } } return 0; } ASM_START ; Has VBE display - Returns true if VBE display detected _vbe_has_vbe_display: push ds push bx mov ax, # BIOSMEM_SEG mov ds, ax mov bx, # BIOSMEM_VBE_FLAG mov al, [bx] and al, #0x01 xor ah, ah pop bx pop ds ret ; VBE Init - Initialise the Vesa Bios Extension Code ; This function does a sanity check on the host side display code interface. vbe_init: mov ax, # VBE_DISPI_ID0 call dispi_set_id call dispi_get_id cmp ax, # VBE_DISPI_ID0 jne no_vbe_interface push ds push bx mov ax, # BIOSMEM_SEG mov ds, ax mov bx, # BIOSMEM_VBE_FLAG mov al, #0x01 mov [bx], al pop bx pop ds mov ax, # VBE_DISPI_ID3 call dispi_set_id no_vbe_interface: #if defined(USE_BX_INFO) || defined(DEBUG) mov bx, #msg_vbe_init push bx call _printf inc sp inc sp #endif ret ; VBE Display Info - Display information on screen about the VBE vbe_display_info: call _vbe_has_vbe_display test ax, ax jz no_vbe_flag mov ax, #0xc000 mov ds, ax mov si, #_vbebios_info_string jmp _display_string no_vbe_flag: mov ax, #0xc000 mov ds, ax mov si, #_no_vbebios_info_string jmp _display_string ASM_END /** Function 00h - Return VBE Controller Information * * Input: * AX = 4F00h * ES:DI = Pointer to buffer in which to place VbeInfoBlock structure * (VbeSignature should be VBE2 when VBE 2.0 information is desired and * the info block is 512 bytes in size) * Output: * AX = VBE Return Status * */ void vbe_biosfn_return_controller_information(AX, ES, DI) Bit16u *AX;Bit16u ES;Bit16u DI; { Bit16u ss=get_SS(); VbeInfoBlock vbe_info_block; Bit16u status; Bit16u result; Bit16u vbe2_info; Bit16u cur_mode=0; Bit16u cur_ptr=34; ModeInfoListItem *cur_info=&mode_info_list; status = read_word(ss, AX); #ifdef DEBUG printf("VBE vbe_biosfn_return_vbe_info ES%x DI%x AX%x\n",ES,DI,status); #endif vbe2_info = 0; #ifdef VBE2_NO_VESA_CHECK #else // get vbe_info_block into local variable memcpyb(ss, &vbe_info_block, ES, DI, sizeof(vbe_info_block)); // check for VBE2 signature if (((vbe_info_block.VbeSignature[0] == 'V') && (vbe_info_block.VbeSignature[1] == 'B') && (vbe_info_block.VbeSignature[2] == 'E') && (vbe_info_block.VbeSignature[3] == '2')) || ((vbe_info_block.VbeSignature[0] == 'V') && (vbe_info_block.VbeSignature[1] == 'E') && (vbe_info_block.VbeSignature[2] == 'S') && (vbe_info_block.VbeSignature[3] == 'A')) ) { vbe2_info = 1; #ifdef DEBUG printf("VBE correct VESA/VBE2 signature found\n"); #endif } #endif // VBE Signature vbe_info_block.VbeSignature[0] = 'V'; vbe_info_block.VbeSignature[1] = 'E'; vbe_info_block.VbeSignature[2] = 'S'; vbe_info_block.VbeSignature[3] = 'A'; // VBE Version supported vbe_info_block.VbeVersion = 0x0200; // OEM String vbe_info_block.OemStringPtr_Seg = 0xc000; vbe_info_block.OemStringPtr_Off = &vbebios_copyright; // Capabilities vbe_info_block.Capabilities[0] = VBE_CAPABILITY_8BIT_DAC; vbe_info_block.Capabilities[1] = 0; vbe_info_block.Capabilities[2] = 0; vbe_info_block.Capabilities[3] = 0; #ifdef DYN_LIST // VBE Video Mode Pointer (dynamicly generated from the mode_info_list) vbe_info_block.VideoModePtr_Seg= ES ; vbe_info_block.VideoModePtr_Off= DI + 34; #else // VBE Video Mode Pointer (staticly in rom) vbe_info_block.VideoModePtr_Seg = 0xc000; vbe_info_block.VideoModePtr_Off = &vbebios_mode_list; #endif // VBE Total Memory (in 64b blocks) vbe_info_block.TotalMemory = VBE_TOTAL_VIDEO_MEMORY_DIV_64K; if (vbe2_info) { // OEM Stuff vbe_info_block.OemSoftwareRev = VBE_OEM_SOFTWARE_REV; vbe_info_block.OemVendorNamePtr_Seg = 0xc000; vbe_info_block.OemVendorNamePtr_Off = &vbebios_vendor_name; vbe_info_block.OemProductNamePtr_Seg = 0xc000; vbe_info_block.OemProductNamePtr_Off = &vbebios_product_name; vbe_info_block.OemProductRevPtr_Seg = 0xc000; vbe_info_block.OemProductRevPtr_Off = &vbebios_product_revision; // copy updates in vbe_info_block back memcpyb(ES, DI, ss, &vbe_info_block, sizeof(vbe_info_block)); } else { // copy updates in vbe_info_block back (VBE 1.x compatibility) memcpyb(ES, DI, ss, &vbe_info_block, 256); } #ifdef DYN_LIST do { if (cur_info->info.BitsPerPixel <= dispi_get_max_bpp()) { #ifdef DEBUG printf("VBE found mode %x => %x\n", cur_info->mode,cur_mode); #endif write_word(ES, DI + cur_ptr, cur_info->mode); cur_mode++; cur_ptr+=2; } cur_info++; } while (cur_info->mode != VBE_VESA_MODE_END_OF_LIST); // Add vesa mode list terminator write_word(ES, DI + cur_ptr, cur_info->mode); #endif result = 0x4f; write_word(ss, AX, result); } /** Function 01h - Return VBE Mode Information * * Input: * AX = 4F01h * CX = Mode Number * ES:DI = Pointer to buffer in which to place ModeInfoBlock structure * Output: * AX = VBE Return Status * */ void vbe_biosfn_return_mode_information(AX, CX, ES, DI) Bit16u *AX;Bit16u CX; Bit16u ES;Bit16u DI; { Bit16u result=0x0100; Bit16u ss=get_SS(); ModeInfoBlock info; ModeInfoListItem *cur_info; Boolean using_lfb; #ifdef DEBUG printf("VBE vbe_biosfn_return_mode_information ES%x DI%x CX%x\n",ES,DI,CX); #endif using_lfb=((CX & VBE_MODE_LINEAR_FRAME_BUFFER) == VBE_MODE_LINEAR_FRAME_BUFFER); CX = (CX & 0x1ff); cur_info = mode_info_find_mode(CX, using_lfb, &cur_info); if (cur_info != 0) { #ifdef DEBUG printf("VBE found mode %x\n",CX); #endif memsetb(ss, &info, 0, sizeof(ModeInfoBlock)); memcpyb(ss, &info, 0xc000, &(cur_info->info), sizeof(ModeInfoBlockCompact)); if (info.WinAAttributes & VBE_WINDOW_ATTRIBUTE_RELOCATABLE) { info.WinFuncPtr = 0xC0000000UL; *(Bit16u *)&(info.WinFuncPtr) = (Bit16u)(dispi_set_bank_farcall); } result = 0x4f; } else { #ifdef DEBUG printf("VBE *NOT* found mode %x\n",CX); #endif result = 0x100; } if (result == 0x4f) { // copy updates in mode_info_block back memcpyb(ES, DI, ss, &info, sizeof(info)); } write_word(ss, AX, result); } /** Function 02h - Set VBE Mode * * Input: * AX = 4F02h * BX = Desired Mode to set * ES:DI = Pointer to CRTCInfoBlock structure * Output: * AX = VBE Return Status * */ void vbe_biosfn_set_mode(AX, BX, ES, DI) Bit16u *AX;Bit16u BX; Bit16u ES;Bit16u DI; { Bit16u ss = get_SS(); Bit16u result; ModeInfoListItem *cur_info; Boolean using_lfb; Bit8u no_clear; Bit8u lfb_flag; using_lfb=((BX & VBE_MODE_LINEAR_FRAME_BUFFER) == VBE_MODE_LINEAR_FRAME_BUFFER); lfb_flag=using_lfb?VBE_DISPI_LFB_ENABLED:0; no_clear=((BX & VBE_MODE_PRESERVE_DISPLAY_MEMORY) == VBE_MODE_PRESERVE_DISPLAY_MEMORY)?VBE_DISPI_NOCLEARMEM:0; BX = (BX & 0x1ff); //result=read_word(ss,AX); // check for non vesa mode if (BXinfo.XResolution, cur_info->info.YResolution, cur_info->info.BitsPerPixel); #endif // first disable current mode (when switching between vesa modi) dispi_set_enable(VBE_DISPI_DISABLED); if (cur_info->mode == VBE_VESA_MODE_800X600X4) { biosfn_set_video_mode(0x6a); } dispi_set_bpp(cur_info->info.BitsPerPixel); dispi_set_xres(cur_info->info.XResolution); dispi_set_yres(cur_info->info.YResolution); dispi_set_bank(0); dispi_set_enable(VBE_DISPI_ENABLED | no_clear | lfb_flag); write_word(BIOSMEM_SEG,BIOSMEM_VBE_MODE,BX); write_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL,(0x60 | no_clear)); result = 0x4f; } else { #ifdef DEBUG printf("VBE *NOT* found mode %x\n" , BX); #endif result = 0x100; // FIXME: redirect non VBE modi to normal VGA bios operation // (switch back to VGA mode if (BX == 3) result = 0x4f; } write_word(ss, AX, result); } /** Function 03h - Return Current VBE Mode * * Input: * AX = 4F03h * Output: * AX = VBE Return Status * BX = Current VBE Mode * */ ASM_START vbe_biosfn_return_current_mode: push ds mov ax, # BIOSMEM_SEG mov ds, ax call dispi_get_enable and ax, # VBE_DISPI_ENABLED jz no_vbe_mode mov bx, # BIOSMEM_VBE_MODE mov ax, [bx] mov bx, ax jnz vbe_03_ok no_vbe_mode: mov bx, # BIOSMEM_CURRENT_MODE mov al, [bx] mov bl, al xor bh, bh vbe_03_ok: mov ax, #0x004f pop ds ret ASM_END /** Function 04h - Save/Restore State * * Input: * AX = 4F04h * DL = 00h Return Save/Restore State buffer size * 01h Save State * 02h Restore State * CX = Requested states * ES:BX = Pointer to buffer (if DL <> 00h) * Output: * AX = VBE Return Status * BX = Number of 64-byte blocks to hold the state buffer (if DL=00h) * */ void vbe_biosfn_save_restore_state(AX, DL, CX, ES, BX) { } /** Function 05h - Display Window Control * * Input: * AX = 4F05h * (16-bit) BH = 00h Set memory window * = 01h Get memory window * BL = Window number * = 00h Window A * = 01h Window B * DX = Window number in video memory in window * granularity units (Set Memory Window only) * Note: * If this function is called while in a linear frame buffer mode, * this function must fail with completion code AH=03h * * Output: * AX = VBE Return Status * DX = Window number in window granularity units * (Get Memory Window only) */ ASM_START vbe_biosfn_display_window_control: cmp bl, #0x00 jne vbe_05_failed cmp bh, #0x01 je get_display_window jb set_display_window mov ax, #0x0100 ret set_display_window: mov ax, dx call _dispi_set_bank call dispi_get_bank cmp ax, dx jne vbe_05_failed mov ax, #0x004f ret get_display_window: call dispi_get_bank mov dx, ax mov ax, #0x004f ret vbe_05_failed: mov ax, #0x014f ret ASM_END /** Function 06h - Set/Get Logical Scan Line Length * * Input: * AX = 4F06h * BL = 00h Set Scan Line Length in Pixels * = 01h Get Scan Line Length * = 02h Set Scan Line Length in Bytes * = 03h Get Maximum Scan Line Length * CX = If BL=00h Desired Width in Pixels * If BL=02h Desired Width in Bytes * (Ignored for Get Functions) * * Output: * AX = VBE Return Status * BX = Bytes Per Scan Line * CX = Actual Pixels Per Scan Line * (truncated to nearest complete pixel) * DX = Maximum Number of Scan Lines */ ASM_START vbe_biosfn_set_get_logical_scan_line_length: mov ax, cx cmp bl, #0x01 je get_logical_scan_line_length cmp bl, #0x02 je set_logical_scan_line_bytes jb set_logical_scan_line_pixels mov ax, #0x0100 ret set_logical_scan_line_bytes: push ax call dispi_get_bpp xor bh, bh mov bl, ah xor dx, dx pop ax div bx set_logical_scan_line_pixels: call dispi_set_virt_width get_logical_scan_line_length: call dispi_get_bpp xor bh, bh mov bl, ah call dispi_get_virt_width mov cx, ax mul bx mov bx, ax call dispi_get_virt_height mov dx, ax mov ax, #0x004f ret ASM_END /** Function 07h - Set/Get Display Start * * Input(16-bit): * AX = 4F07h * BH = 00h Reserved and must be 00h * BL = 00h Set Display Start * = 01h Get Display Start * = 02h Schedule Display Start (Alternate) * = 03h Schedule Stereoscopic Display Start * = 04h Get Scheduled Display Start Status * = 05h Enable Stereoscopic Mode * = 06h Disable Stereoscopic Mode * = 80h Set Display Start during Vertical Retrace * = 82h Set Display Start during Vertical Retrace (Alternate) * = 83h Set Stereoscopic Display Start during Vertical Retrace * ECX = If BL=02h/82h Display Start Address in bytes * If BL=03h/83h Left Image Start Address in bytes * EDX = If BL=03h/83h Right Image Start Address in bytes * CX = If BL=00h/80h First Displayed Pixel In Scan Line * DX = If BL=00h/80h First Displayed Scan Line * * Output: * AX = VBE Return Status * BH = If BL=01h Reserved and will be 0 * CX = If BL=01h First Displayed Pixel In Scan Line * If BL=04h 0 if flip has not occurred, not 0 if it has * DX = If BL=01h First Displayed Scan Line * * Input(32-bit): * BH = 00h Reserved and must be 00h * BL = 00h Set Display Start * = 80h Set Display Start during Vertical Retrace * CX = Bits 0-15 of display start address * DX = Bits 16-31 of display start address * ES = Selector for memory mapped registers */ ASM_START vbe_biosfn_set_get_display_start: cmp bl, #0x80 je set_display_start cmp bl, #0x01 je get_display_start jb set_display_start mov ax, #0x0100 ret set_display_start: mov ax, cx call dispi_set_x_offset mov ax, dx call dispi_set_y_offset mov ax, #0x004f ret get_display_start: call dispi_get_x_offset mov cx, ax call dispi_get_y_offset mov dx, ax xor bh, bh mov ax, #0x004f ret ASM_END /** Function 08h - Set/Get Dac Palette Format * * Input: * AX = 4F08h * BL = 00h set DAC palette width * = 01h get DAC palette width * BH = If BL=00h: desired number of bits per primary color * Output: * AX = VBE Return Status * BH = current number of bits per primary color (06h = standard VGA) */ ASM_START vbe_biosfn_set_get_dac_palette_format: cmp bl, #0x01 je get_dac_palette_format jb set_dac_palette_format mov ax, #0x0100 ret set_dac_palette_format: call dispi_get_enable cmp bh, #0x06 je set_normal_dac cmp bh, #0x08 jne vbe_08_unsupported or ax, # VBE_DISPI_8BIT_DAC jnz set_dac_mode set_normal_dac: and ax, #~ VBE_DISPI_8BIT_DAC set_dac_mode: call _dispi_set_enable get_dac_palette_format: mov bh, #0x06 call dispi_get_enable and ax, # VBE_DISPI_8BIT_DAC jz vbe_08_ok mov bh, #0x08 vbe_08_ok: mov ax, #0x004f ret vbe_08_unsupported: mov ax, #0x014f ret ASM_END /** Function 09h - Set/Get Palette Data * * Input: * AX = 4F09h * Output: * AX = VBE Return Status * * FIXME: incomplete API description, Input & Output */ void vbe_biosfn_set_get_palette_data(AX) { } /** Function 0Ah - Return VBE Protected Mode Interface * * Input: * AX = 4F0Ah * Output: * AX = VBE Return Status * * FIXME: incomplete API description, Input & Output */ void vbe_biosfn_return_protected_mode_interface(AX) { }