;; ============================================================================================
;;
;; 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
;;
;; ============================================================================================
; Oracle LGPL Disclaimer: For the avoidance of doubt, except that if any license choice
; other than GPL or LGPL is available it will apply instead, Oracle elects to use only
; the Lesser General Public License version 2.1 (LGPLv2) at this time for any software where
; a choice of LGPL license versions is made available with the language indicating
; that LGPLv2 or any later version may be used, or where a choice of which version
; of the LGPL is applied is otherwise unspecified.
include vgadefs.inc
public _vga_compat_setup
public dispi_set_enable_
public dispi_set_bank_
public _dispi_set_bank_farcall
public _dispi_get_max_bpp
public _vbe_has_vbe_display
public vbe_biosfn_return_current_mode
public vbe_biosfn_display_window_control
public vbe_biosfn_set_get_logical_scan_line_length
public vbe_biosfn_set_get_display_start
public vbe_biosfn_set_get_dac_palette_format
public vbe_biosfn_set_get_palette_data
public vbe_biosfn_return_protected_mode_interface
VGAROM segment public 'CODE'
.386
VBE_BYTEWISE_IO EQU 1
;; Bytewise in/out
ifdef VBE_BYTEWISE_IO
public do_out_dx_ax
public do_in_ax_dx
do_out_dx_ax:
xchg ah, al
out dx, al
xchg ah, al
out dx, al
ret
do_in_ax_dx:
in al, dx
xchg ah, al
in al, dx
ret
out_dx_ax EQU call do_out_dx_ax
in_ax_dx EQU call do_in_ax_dx
else
out_dx_ax EQU out dx, ax
in_ax_dx EQU in ax, dx
endif
;; Vertical retrace waiting
wait_vsync:
push ax
push dx
mov dx, 03DAh ; @todo use a symbolic constant!
wv_loop:
in al, dx
test al, 8
jz wv_loop
pop dx
pop ax
ret
wait_not_vsync:
push ax
push dx
mov dx, 03DAh ; @todo use a symbolic constant!
wnv_loop:
in al, dx
test al, 8
jnz wnv_loop
pop dx
pop ax
ret
; 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
cmp al, 4
jbe get_bpp_noinc
mov ah, al
shr ah, 3
test al, 07
jz get_bpp_noinc
inc ah
get_bpp_noinc:
pop dx
ret
; get display capabilities
_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
_dispi_set_bank_farcall:
cmp bx, 0100h
je dispi_set_bank_farcall_get
or bx,bx
jnz dispi_set_bank_farcall_error
mov ax, dx
push dx
push ax
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
in_ax_dx
pop dx
cmp dx,ax
jne dispi_set_bank_farcall_error
mov ax, 004Fh
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, 014Fh
retf
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, 4
ja set_width_svga
shr bx, 1
set_width_svga:
shr bx, 3
mov dx, VGAREG_VGA_CRTC_ADDRESS
mov ah, bl
mov al, 13h
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
_vga_compat_setup:
push ax
push dx
; set CRT X resolution
mov dx, VBE_DISPI_IOPORT_INDEX
mov ax, VBE_DISPI_INDEX_XRES
out_dx_ax
mov dx, VBE_DISPI_IOPORT_DATA
in_ax_dx
push ax
mov dx, VGAREG_VGA_CRTC_ADDRESS
mov ax, 0011h
out dx, ax
pop ax
push ax
shr ax, 3
dec ax
mov ah, al
mov al, 01
out dx, ax
pop ax
call vga_set_virt_width
; set CRT Y resolution
mov dx, VBE_DISPI_IOPORT_INDEX
mov ax, VBE_DISPI_INDEX_YRES
out_dx_ax
mov dx, VBE_DISPI_IOPORT_DATA
in_ax_dx
dec ax
push ax
mov dx, VGAREG_VGA_CRTC_ADDRESS
mov ah, al
mov al, 12h
out dx, ax
pop ax
mov al, 07
out dx, al
inc dx
in al, dx
and al, 0BDh
test ah, 01
jz bit8_clear
or al, 02
bit8_clear:
test ah, 02
jz bit9_clear
or al, 40h
bit9_clear:
out dx, al
; other settings
mov dx, VGAREG_VGA_CRTC_ADDRESS
mov ax, 0009
out dx, al
mov dx, VGAREG_VGA_CRTC_DATA
in al, dx
and al, 60h ; clear double scan bit and cell height
out dx, al
mov dx, VGAREG_VGA_CRTC_ADDRESS
mov al, 17h
out dx, al
mov dx, VGAREG_VGA_CRTC_DATA
in al, dx
or al, 03
out dx, al
mov dx, VGAREG_ACTL_RESET
in al, dx
mov dx, VGAREG_ACTL_ADDRESS
mov al, 10h
out dx, al
mov dx, VGAREG_ACTL_READ_DATA
in al, dx
or al, 01
mov dx, VGAREG_ACTL_ADDRESS
out dx, al
mov al, 20h
out dx, al
mov dx, VGAREG_GRDC_ADDRESS
mov ax, 0506h
out dx, ax
mov dx, VGAREG_SEQU_ADDRESS
mov ax, 0F02h
out dx, ax
; settings for >= 8bpp
mov dx, VBE_DISPI_IOPORT_INDEX
mov ax, VBE_DISPI_INDEX_BPP
out_dx_ax
mov dx, VBE_DISPI_IOPORT_DATA
in_ax_dx
cmp al, 08
jb vga_compat_end
mov dx, VGAREG_VGA_CRTC_ADDRESS
mov al, 14h
out dx, al
mov dx, VGAREG_VGA_CRTC_DATA
in al, dx
or al, 40h
out dx, al
mov dx, VGAREG_ACTL_RESET
in al, dx
mov dx, VGAREG_ACTL_ADDRESS
mov al, 10h
out dx, al
mov dx, VGAREG_ACTL_READ_DATA
in al, dx
or al, 40h
mov dx, VGAREG_ACTL_ADDRESS
out dx, al
mov al, 20h
out dx, al
mov dx, VGAREG_SEQU_ADDRESS
mov al, 04
out dx, al
mov dx, VGAREG_SEQU_DATA
in al, dx
or al, 08
out dx, al
mov dx, VGAREG_GRDC_ADDRESS
mov al, 05
out dx, al
mov dx, VGAREG_GRDC_DATA
in al, dx
and al, 9Fh
or al, 40h
out dx, al
vga_compat_end:
pop dx
pop ax
; 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, 01
xor ah, ah
pop bx
pop ds
ret
; Function 03h - Return Current VBE Mode
;
; Input:
; AX = 4F03h
; Output:
; AX = VBE Return Status
; BX = Current VBE Mode
;
;
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, 004Fh
pop ds
ret
; 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)
vbe_biosfn_display_window_control:
cmp bl, 0
jne vbe_05_failed
cmp bh, 1
je get_display_window
jb set_display_window
mov ax, 0100h
ret
set_display_window:
mov ax, dx
call dispi_set_bank_
call dispi_get_bank
cmp ax, dx
jne vbe_05_failed
mov ax, 004Fh
ret
get_display_window:
call dispi_get_bank
mov dx, ax
mov ax, 004Fh
ret
vbe_05_failed:
mov ax, 014Fh
ret
; 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
;
vbe_biosfn_set_get_logical_scan_line_length:
mov ax, cx
cmp bl, 1
je get_logical_scan_line_length
cmp bl, 2
je set_logical_scan_line_bytes
jb set_logical_scan_line_pixels
mov ax, 0100h
ret
set_logical_scan_line_bytes:
push ax
call dispi_get_bpp
xor bh, bh
mov bl, ah
or bl, bl
jnz no_4bpp_1
shl ax, 3
mov bl, 1
no_4bpp_1:
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
or bl, bl
jnz no_4bpp_2
shr ax, 3
mov bl, 1
no_4bpp_2:
mul bx
mov bx, ax
call dispi_get_virt_height
mov dx, ax
mov ax, 004Fh
ret
; 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
;
vbe_biosfn_set_get_display_start:
cmp bl, 80h
je set_display_start_wait
cmp bl, 1
je get_display_start
jb set_display_start
mov ax, 0100h
ret
set_display_start_wait:
call wait_not_vsync
call wait_vsync
set_display_start:
mov ax, cx
call dispi_set_x_offset
mov ax, dx
call dispi_set_y_offset
mov ax, 004Fh
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, 004Fh
ret
; 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)
;
vbe_biosfn_set_get_dac_palette_format:
cmp bl, 1
je get_dac_palette_format
jb set_dac_palette_format
mov ax, 0100h
ret
set_dac_palette_format:
call dispi_get_enable
cmp bh, 6
je set_normal_dac
cmp bh, 8
jne vbe_08_unsupported
or ax, VBE_DISPI_8BIT_DAC
jnz set_dac_mode
set_normal_dac:
and ax, NOT VBE_DISPI_8BIT_DAC
set_dac_mode:
call dispi_set_enable_
get_dac_palette_format:
mov bh, 6
call dispi_get_enable
and ax, VBE_DISPI_8BIT_DAC
jz vbe_08_ok
mov bh, 8
vbe_08_ok:
mov ax, 004Fh
ret
vbe_08_unsupported:
mov ax, 014Fh
ret
; Function 09h - Set/Get Palette Data
;
; Input:
; AX = 4F09h
; (16-bit) BL = 00h Set palette data
; = 01h Get palette data
; = 02h Set secondary palette data
; = 03h Get secondary palette data
; = 80h Set palette data during VRetrace
; CX = Number of entries to update (<= 256)
; DX = First entry to update
; ES:DI = Table of palette values
; Output:
; AX = VBE Return Status
;
; Notes:
; Secondary palette support is a "future extension".
; Attempts to set/get it should return status 02h.
;
; In VBE 3.0, reading palette data is optional and
; subfunctions 01h and 03h may return failure.
;
; The format of palette entries is as follows:
;
; PaletteEntry struc
; Blue db ? ; Blue channel value (6 or 8 bits)
; Green db ? ; Green channel value (6 or 8 bits)
; Red db ? ; Red channel value (6 or 8 bits)
; Padding db ? ; DWORD alignment byte (unused)
; PaletteEntry ends
;
; Most applications use VGA DAC registers directly to
; set/get palette in VBE modes. However, subfn 4F09h is
; required for NonVGA controllers (eg. XGA).
;
vbe_biosfn_set_get_palette_data:
test bl, bl
jz set_palette_data
cmp bl, 01
je get_palette_data
cmp bl, 03
jbe vbe_09_nohw
cmp bl, 80h
jne vbe_09_unsupported
if 0
; this is where we could wait for vertical retrace
endif
set_palette_data:
pushad
push ds
push es
pop ds
mov al, dl
mov dx, VGAREG_DAC_WRITE_ADDRESS
out dx, al
inc dx
mov si, di
set_pal_loop:
lodsd
ror eax, 16
out dx, al
rol eax, 8
out dx, al
rol eax, 8
out dx, al
loop set_pal_loop
pop ds
popad
vbe_09_ok:
mov ax, 004Fh
ret
get_palette_data:
pushad
mov al, dl
mov dx, VGAREG_DAC_READ_ADDRESS
out dx, al
add dl, 2
get_pal_loop:
xor eax, eax
in al, dx
shl eax, 8
in al, dx
shl eax, 8
in al, dx
stosd
loop get_pal_loop
popad
jmp vbe_09_ok
vbe_09_unsupported:
mov ax, 014Fh
ret
vbe_09_nohw:
mov ax, 024Fh
ret
; Function 0Ah - Return VBE Protected Mode Interface
;
; Input: AX = 4F0Ah VBE 2.0 Protected Mode Interface
; BL = 00h Return protected mode table
; Output: AX = Status
; ES = Real Mode Segment of Table
; DI = Offset of Table
; CX = Length of Table including protected mode code
; (for copying purposes)
;
vbe_biosfn_return_protected_mode_interface:
test bl, bl
jnz _fail
mov di, 0C000h
mov es, di
mov di, offset vesa_pm_start
mov cx, vesa_pm_end - vesa_pm_start
sub cx, di
mov ax, 004Fh
ret
_fail:
mov ax, 014fh
ret
VGAROM ends
;;
;; 32-bit VBE interface
;;
.386
public vesa_pm_start
public vesa_pm_end
VBE32 segment public use32 'CODE'
align 2
vesa_pm_start:
dw vesa_pm_set_window - vesa_pm_start
dw vesa_pm_set_display_start - vesa_pm_start
dw vesa_pm_unimplemented - vesa_pm_start
dw vesa_pm_io_ports_table - vesa_pm_start
vesa_pm_io_ports_table:
dw VBE_DISPI_IOPORT_INDEX
dw VBE_DISPI_IOPORT_INDEX + 1
dw VBE_DISPI_IOPORT_DATA
dw VBE_DISPI_IOPORT_DATA + 1
dw 3B6h
dw 3B7h
dw 0FFFFh
dw 0FFFFh
vesa_pm_set_window:
cmp bx, 0
je vesa_pm_set_display_window1
mov ax, 0100h
ret
vesa_pm_set_display_window1:
mov ax, dx
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
in ax, dx
pop dx
cmp dx, ax
jne illegal_window
mov ax, 004Fh
ret
illegal_window:
mov ax, 014Fh
ret
vesa_pm_set_display_start:
cmp bl, 80h
je vesa_pm_set_display_start1_wait
cmp bl, 00
je vesa_pm_set_display_start1
mov ax, 0100h
ret
vesa_pm_set_display_start1_wait:
push edx
mov dx, 03DAh ; @todo: use symbolic constant
wnv_loop_32:
in al, dx
test al, 8
jnz wnv_loop_32
wv_loop_32:
in al, dx
test al, 8
jz wv_loop_32
pop edx
vesa_pm_set_display_start1:
; convert offset to (X, Y) coordinate
; (would be simpler to change Bochs VBE API...)
push eax
push ecx
push edx
push esi
push edi
shl edx, 16
and ecx, 0FFFFh
or ecx, edx
shl ecx, 2
mov eax, ecx
push eax
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
movzx ecx, ax
mov dx, VBE_DISPI_IOPORT_INDEX
mov ax, VBE_DISPI_INDEX_BPP
out dx, ax
mov dx, VBE_DISPI_IOPORT_DATA
in ax, dx
movzx esi, ax
pop eax
cmp esi, 4
jz bpp4_mode
add esi, 7
shr esi, 3
imul ecx, esi
xor edx, edx
div ecx
mov edi, eax
mov eax, edx
xor edx, edx
div esi
jmp set_xy_regs
bpp4_mode:
shr ecx, 1
xor edx, edx
div ecx
mov edi, eax
mov eax, edx
shl eax, 1
set_xy_regs:
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
mov ax, di
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
pop edi
pop esi
pop edx
pop ecx
pop eax
mov ax, 004fh
ret
vesa_pm_unimplemented:
mov ax, 014Fh
ret
vesa_pm_end:
VBE32 ends
end