linux/arch/i386/boot/video.S
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

2008 lines
40 KiB
ArmAsm

/* video.S
*
* Display adapter & video mode setup, version 2.13 (14-May-99)
*
* Copyright (C) 1995 -- 1998 Martin Mares <mj@ucw.cz>
* Based on the original setup.S code (C) Linus Torvalds and Mats Anderson
*
* Rewritten to use GNU 'as' by Chris Noe <stiker@northlink.com> May 1999
*
* For further information, look at Documentation/svga.txt.
*
*/
#include <linux/config.h> /* for CONFIG_VIDEO_* */
/* Enable autodetection of SVGA adapters and modes. */
#undef CONFIG_VIDEO_SVGA
/* Enable autodetection of VESA modes */
#define CONFIG_VIDEO_VESA
/* Enable compacting of mode table */
#define CONFIG_VIDEO_COMPACT
/* Retain screen contents when switching modes */
#define CONFIG_VIDEO_RETAIN
/* Enable local mode list */
#undef CONFIG_VIDEO_LOCAL
/* Force 400 scan lines for standard modes (hack to fix bad BIOS behaviour */
#undef CONFIG_VIDEO_400_HACK
/* Hack that lets you force specific BIOS mode ID and specific dimensions */
#undef CONFIG_VIDEO_GFX_HACK
#define VIDEO_GFX_BIOS_AX 0x4f02 /* 800x600 on ThinkPad */
#define VIDEO_GFX_BIOS_BX 0x0102
#define VIDEO_GFX_DUMMY_RESOLUTION 0x6425 /* 100x37 */
/* This code uses an extended set of video mode numbers. These include:
* Aliases for standard modes
* NORMAL_VGA (-1)
* EXTENDED_VGA (-2)
* ASK_VGA (-3)
* Video modes numbered by menu position -- NOT RECOMMENDED because of lack
* of compatibility when extending the table. These are between 0x00 and 0xff.
*/
#define VIDEO_FIRST_MENU 0x0000
/* Standard BIOS video modes (BIOS number + 0x0100) */
#define VIDEO_FIRST_BIOS 0x0100
/* VESA BIOS video modes (VESA number + 0x0200) */
#define VIDEO_FIRST_VESA 0x0200
/* Video7 special modes (BIOS number + 0x0900) */
#define VIDEO_FIRST_V7 0x0900
/* Special video modes */
#define VIDEO_FIRST_SPECIAL 0x0f00
#define VIDEO_80x25 0x0f00
#define VIDEO_8POINT 0x0f01
#define VIDEO_80x43 0x0f02
#define VIDEO_80x28 0x0f03
#define VIDEO_CURRENT_MODE 0x0f04
#define VIDEO_80x30 0x0f05
#define VIDEO_80x34 0x0f06
#define VIDEO_80x60 0x0f07
#define VIDEO_GFX_HACK 0x0f08
#define VIDEO_LAST_SPECIAL 0x0f09
/* Video modes given by resolution */
#define VIDEO_FIRST_RESOLUTION 0x1000
/* The "recalculate timings" flag */
#define VIDEO_RECALC 0x8000
/* Positions of various video parameters passed to the kernel */
/* (see also include/linux/tty.h) */
#define PARAM_CURSOR_POS 0x00
#define PARAM_VIDEO_PAGE 0x04
#define PARAM_VIDEO_MODE 0x06
#define PARAM_VIDEO_COLS 0x07
#define PARAM_VIDEO_EGA_BX 0x0a
#define PARAM_VIDEO_LINES 0x0e
#define PARAM_HAVE_VGA 0x0f
#define PARAM_FONT_POINTS 0x10
#define PARAM_LFB_WIDTH 0x12
#define PARAM_LFB_HEIGHT 0x14
#define PARAM_LFB_DEPTH 0x16
#define PARAM_LFB_BASE 0x18
#define PARAM_LFB_SIZE 0x1c
#define PARAM_LFB_LINELENGTH 0x24
#define PARAM_LFB_COLORS 0x26
#define PARAM_VESAPM_SEG 0x2e
#define PARAM_VESAPM_OFF 0x30
#define PARAM_LFB_PAGES 0x32
#define PARAM_VESA_ATTRIB 0x34
/* Define DO_STORE according to CONFIG_VIDEO_RETAIN */
#ifdef CONFIG_VIDEO_RETAIN
#define DO_STORE call store_screen
#else
#define DO_STORE
#endif /* CONFIG_VIDEO_RETAIN */
# This is the main entry point called by setup.S
# %ds *must* be pointing to the bootsector
video: pushw %ds # We use different segments
pushw %ds # FS contains original DS
popw %fs
pushw %cs # DS is equal to CS
popw %ds
pushw %cs # ES is equal to CS
popw %es
xorw %ax, %ax
movw %ax, %gs # GS is zero
cld
call basic_detect # Basic adapter type testing (EGA/VGA/MDA/CGA)
#ifdef CONFIG_VIDEO_SELECT
movw %fs:(0x01fa), %ax # User selected video mode
cmpw $ASK_VGA, %ax # Bring up the menu
jz vid2
call mode_set # Set the mode
jc vid1
leaw badmdt, %si # Invalid mode ID
call prtstr
vid2: call mode_menu
vid1:
#ifdef CONFIG_VIDEO_RETAIN
call restore_screen # Restore screen contents
#endif /* CONFIG_VIDEO_RETAIN */
call store_edid
#endif /* CONFIG_VIDEO_SELECT */
call mode_params # Store mode parameters
popw %ds # Restore original DS
ret
# Detect if we have CGA, MDA, EGA or VGA and pass it to the kernel.
basic_detect:
movb $0, %fs:(PARAM_HAVE_VGA)
movb $0x12, %ah # Check EGA/VGA
movb $0x10, %bl
int $0x10
movw %bx, %fs:(PARAM_VIDEO_EGA_BX) # Identifies EGA to the kernel
cmpb $0x10, %bl # No, it's a CGA/MDA/HGA card.
je basret
incb adapter
movw $0x1a00, %ax # Check EGA or VGA?
int $0x10
cmpb $0x1a, %al # 1a means VGA...
jne basret # anything else is EGA.
incb %fs:(PARAM_HAVE_VGA) # We've detected a VGA
incb adapter
basret: ret
# Store the video mode parameters for later usage by the kernel.
# This is done by asking the BIOS except for the rows/columns
# parameters in the default 80x25 mode -- these are set directly,
# because some very obscure BIOSes supply insane values.
mode_params:
#ifdef CONFIG_VIDEO_SELECT
cmpb $0, graphic_mode
jnz mopar_gr
#endif
movb $0x03, %ah # Read cursor position
xorb %bh, %bh
int $0x10
movw %dx, %fs:(PARAM_CURSOR_POS)
movb $0x0f, %ah # Read page/mode/width
int $0x10
movw %bx, %fs:(PARAM_VIDEO_PAGE)
movw %ax, %fs:(PARAM_VIDEO_MODE) # Video mode and screen width
cmpb $0x7, %al # MDA/HGA => segment differs
jnz mopar0
movw $0xb000, video_segment
mopar0: movw %gs:(0x485), %ax # Font size
movw %ax, %fs:(PARAM_FONT_POINTS) # (valid only on EGA/VGA)
movw force_size, %ax # Forced size?
orw %ax, %ax
jz mopar1
movb %ah, %fs:(PARAM_VIDEO_COLS)
movb %al, %fs:(PARAM_VIDEO_LINES)
ret
mopar1: movb $25, %al
cmpb $0, adapter # If we are on CGA/MDA/HGA, the
jz mopar2 # screen must have 25 lines.
movb %gs:(0x484), %al # On EGA/VGA, use the EGA+ BIOS
incb %al # location of max lines.
mopar2: movb %al, %fs:(PARAM_VIDEO_LINES)
ret
#ifdef CONFIG_VIDEO_SELECT
# Fetching of VESA frame buffer parameters
mopar_gr:
leaw modelist+1024, %di
movb $0x23, %fs:(PARAM_HAVE_VGA)
movw 16(%di), %ax
movw %ax, %fs:(PARAM_LFB_LINELENGTH)
movw 18(%di), %ax
movw %ax, %fs:(PARAM_LFB_WIDTH)
movw 20(%di), %ax
movw %ax, %fs:(PARAM_LFB_HEIGHT)
movb 25(%di), %al
movb $0, %ah
movw %ax, %fs:(PARAM_LFB_DEPTH)
movb 29(%di), %al
movb $0, %ah
movw %ax, %fs:(PARAM_LFB_PAGES)
movl 40(%di), %eax
movl %eax, %fs:(PARAM_LFB_BASE)
movl 31(%di), %eax
movl %eax, %fs:(PARAM_LFB_COLORS)
movl 35(%di), %eax
movl %eax, %fs:(PARAM_LFB_COLORS+4)
movw 0(%di), %ax
movw %ax, %fs:(PARAM_VESA_ATTRIB)
# get video mem size
leaw modelist+1024, %di
movw $0x4f00, %ax
int $0x10
xorl %eax, %eax
movw 18(%di), %ax
movl %eax, %fs:(PARAM_LFB_SIZE)
# switching the DAC to 8-bit is for <= 8 bpp only
movw %fs:(PARAM_LFB_DEPTH), %ax
cmpw $8, %ax
jg dac_done
# get DAC switching capability
xorl %eax, %eax
movb 10(%di), %al
testb $1, %al
jz dac_set
# attempt to switch DAC to 8-bit
movw $0x4f08, %ax
movw $0x0800, %bx
int $0x10
cmpw $0x004f, %ax
jne dac_set
movb %bh, dac_size # store actual DAC size
dac_set:
# set color size to DAC size
movb dac_size, %al
movb %al, %fs:(PARAM_LFB_COLORS+0)
movb %al, %fs:(PARAM_LFB_COLORS+2)
movb %al, %fs:(PARAM_LFB_COLORS+4)
movb %al, %fs:(PARAM_LFB_COLORS+6)
# set color offsets to 0
movb $0, %fs:(PARAM_LFB_COLORS+1)
movb $0, %fs:(PARAM_LFB_COLORS+3)
movb $0, %fs:(PARAM_LFB_COLORS+5)
movb $0, %fs:(PARAM_LFB_COLORS+7)
dac_done:
# get protected mode interface informations
movw $0x4f0a, %ax
xorw %bx, %bx
xorw %di, %di
int $0x10
cmp $0x004f, %ax
jnz no_pm
movw %es, %fs:(PARAM_VESAPM_SEG)
movw %di, %fs:(PARAM_VESAPM_OFF)
no_pm: ret
# The video mode menu
mode_menu:
leaw keymsg, %si # "Return/Space/Timeout" message
call prtstr
call flush
nokey: call getkt
cmpb $0x0d, %al # ENTER ?
je listm # yes - manual mode selection
cmpb $0x20, %al # SPACE ?
je defmd1 # no - repeat
call beep
jmp nokey
defmd1: ret # No mode chosen? Default 80x25
listm: call mode_table # List mode table
listm0: leaw name_bann, %si # Print adapter name
call prtstr
movw card_name, %si
orw %si, %si
jnz an2
movb adapter, %al
leaw old_name, %si
orb %al, %al
jz an1
leaw ega_name, %si
decb %al
jz an1
leaw vga_name, %si
jmp an1
an2: call prtstr
leaw svga_name, %si
an1: call prtstr
leaw listhdr, %si # Table header
call prtstr
movb $0x30, %dl # DL holds mode number
leaw modelist, %si
lm1: cmpw $ASK_VGA, (%si) # End?
jz lm2
movb %dl, %al # Menu selection number
call prtchr
call prtsp2
lodsw
call prthw # Mode ID
call prtsp2
movb 0x1(%si), %al
call prtdec # Rows
movb $0x78, %al # the letter 'x'
call prtchr
lodsw
call prtdec # Columns
movb $0x0d, %al # New line
call prtchr
movb $0x0a, %al
call prtchr
incb %dl # Next character
cmpb $0x3a, %dl
jnz lm1
movb $0x61, %dl
jmp lm1
lm2: leaw prompt, %si # Mode prompt
call prtstr
leaw edit_buf, %di # Editor buffer
lm3: call getkey
cmpb $0x0d, %al # Enter?
jz lment
cmpb $0x08, %al # Backspace?
jz lmbs
cmpb $0x20, %al # Printable?
jc lm3
cmpw $edit_buf+4, %di # Enough space?
jz lm3
stosb
call prtchr
jmp lm3
lmbs: cmpw $edit_buf, %di # Backspace
jz lm3
decw %di
movb $0x08, %al
call prtchr
call prtspc
movb $0x08, %al
call prtchr
jmp lm3
lment: movb $0, (%di)
leaw crlft, %si
call prtstr
leaw edit_buf, %si
cmpb $0, (%si) # Empty string = default mode
jz lmdef
cmpb $0, 1(%si) # One character = menu selection
jz mnusel
cmpw $0x6373, (%si) # "scan" => mode scanning
jnz lmhx
cmpw $0x6e61, 2(%si)
jz lmscan
lmhx: xorw %bx, %bx # Else => mode ID in hex
lmhex: lodsb
orb %al, %al
jz lmuse1
subb $0x30, %al
jc lmbad
cmpb $10, %al
jc lmhx1
subb $7, %al
andb $0xdf, %al
cmpb $10, %al
jc lmbad
cmpb $16, %al
jnc lmbad
lmhx1: shlw $4, %bx
orb %al, %bl
jmp lmhex
lmuse1: movw %bx, %ax
jmp lmuse
mnusel: lodsb # Menu selection
xorb %ah, %ah
subb $0x30, %al
jc lmbad
cmpb $10, %al
jc lmuse
cmpb $0x61-0x30, %al
jc lmbad
subb $0x61-0x30-10, %al
cmpb $36, %al
jnc lmbad
lmuse: call mode_set
jc lmdef
lmbad: leaw unknt, %si
call prtstr
jmp lm2
lmscan: cmpb $0, adapter # Scanning only on EGA/VGA
jz lmbad
movw $0, mt_end # Scanning of modes is
movb $1, scanning # done as new autodetection.
call mode_table
jmp listm0
lmdef: ret
# Additional parts of mode_set... (relative jumps, you know)
setv7: # Video7 extended modes
DO_STORE
subb $VIDEO_FIRST_V7>>8, %bh
movw $0x6f05, %ax
int $0x10
stc
ret
_setrec: jmp setrec # Ugly...
_set_80x25: jmp set_80x25
# Aliases for backward compatibility.
setalias:
movw $VIDEO_80x25, %ax
incw %bx
jz mode_set
movb $VIDEO_8POINT-VIDEO_FIRST_SPECIAL, %al
incw %bx
jnz setbad # Fall-through!
# Setting of user mode (AX=mode ID) => CF=success
mode_set:
movw %ax, %fs:(0x01fa) # Store mode for use in acpi_wakeup.S
movw %ax, %bx
cmpb $0xff, %ah
jz setalias
testb $VIDEO_RECALC>>8, %ah
jnz _setrec
cmpb $VIDEO_FIRST_RESOLUTION>>8, %ah
jnc setres
cmpb $VIDEO_FIRST_SPECIAL>>8, %ah
jz setspc
cmpb $VIDEO_FIRST_V7>>8, %ah
jz setv7
cmpb $VIDEO_FIRST_VESA>>8, %ah
jnc check_vesa
orb %ah, %ah
jz setmenu
decb %ah
jz setbios
setbad: clc
movb $0, do_restore # The screen needn't be restored
ret
setvesa:
DO_STORE
subb $VIDEO_FIRST_VESA>>8, %bh
movw $0x4f02, %ax # VESA BIOS mode set call
int $0x10
cmpw $0x004f, %ax # AL=4f if implemented
jnz setbad # AH=0 if OK
stc
ret
setbios:
DO_STORE
int $0x10 # Standard BIOS mode set call
pushw %bx
movb $0x0f, %ah # Check if really set
int $0x10
popw %bx
cmpb %bl, %al
jnz setbad
stc
ret
setspc: xorb %bh, %bh # Set special mode
cmpb $VIDEO_LAST_SPECIAL-VIDEO_FIRST_SPECIAL, %bl
jnc setbad
addw %bx, %bx
jmp *spec_inits(%bx)
setmenu:
orb %al, %al # 80x25 is an exception
jz _set_80x25
pushw %bx # Set mode chosen from menu
call mode_table # Build the mode table
popw %ax
shlw $2, %ax
addw %ax, %si
cmpw %di, %si
jnc setbad
movw (%si), %ax # Fetch mode ID
_m_s: jmp mode_set
setres: pushw %bx # Set mode chosen by resolution
call mode_table
popw %bx
xchgb %bl, %bh
setr1: lodsw
cmpw $ASK_VGA, %ax # End of the list?
jz setbad
lodsw
cmpw %bx, %ax
jnz setr1
movw -4(%si), %ax # Fetch mode ID
jmp _m_s
check_vesa:
leaw modelist+1024, %di
subb $VIDEO_FIRST_VESA>>8, %bh
movw %bx, %cx # Get mode information structure
movw $0x4f01, %ax
int $0x10
addb $VIDEO_FIRST_VESA>>8, %bh
cmpw $0x004f, %ax
jnz setbad
movb (%di), %al # Check capabilities.
andb $0x19, %al
cmpb $0x09, %al
jz setvesa # This is a text mode
movb (%di), %al # Check capabilities.
andb $0x99, %al
cmpb $0x99, %al
jnz _setbad # Doh! No linear frame buffer.
subb $VIDEO_FIRST_VESA>>8, %bh
orw $0x4000, %bx # Use linear frame buffer
movw $0x4f02, %ax # VESA BIOS mode set call
int $0x10
cmpw $0x004f, %ax # AL=4f if implemented
jnz _setbad # AH=0 if OK
movb $1, graphic_mode # flag graphic mode
movb $0, do_restore # no screen restore
stc
ret
_setbad: jmp setbad # Ugly...
# Recalculate vertical display end registers -- this fixes various
# inconsistencies of extended modes on many adapters. Called when
# the VIDEO_RECALC flag is set in the mode ID.
setrec: subb $VIDEO_RECALC>>8, %ah # Set the base mode
call mode_set
jnc rct3
movw %gs:(0x485), %ax # Font size in pixels
movb %gs:(0x484), %bl # Number of rows
incb %bl
mulb %bl # Number of visible
decw %ax # scan lines - 1
movw $0x3d4, %dx
movw %ax, %bx
movb $0x12, %al # Lower 8 bits
movb %bl, %ah
outw %ax, %dx
movb $0x07, %al # Bits 8 and 9 in the overflow register
call inidx
xchgb %al, %ah
andb $0xbd, %ah
shrb %bh
jnc rct1
orb $0x02, %ah
rct1: shrb %bh
jnc rct2
orb $0x40, %ah
rct2: movb $0x07, %al
outw %ax, %dx
stc
rct3: ret
# Table of routines for setting of the special modes.
spec_inits:
.word set_80x25
.word set_8pixel
.word set_80x43
.word set_80x28
.word set_current
.word set_80x30
.word set_80x34
.word set_80x60
.word set_gfx
# Set the 80x25 mode. If already set, do nothing.
set_80x25:
movw $0x5019, force_size # Override possibly broken BIOS
use_80x25:
#ifdef CONFIG_VIDEO_400_HACK
movw $0x1202, %ax # Force 400 scan lines
movb $0x30, %bl
int $0x10
#else
movb $0x0f, %ah # Get current mode ID
int $0x10
cmpw $0x5007, %ax # Mode 7 (80x25 mono) is the only one available
jz st80 # on CGA/MDA/HGA and is also available on EGAM
cmpw $0x5003, %ax # Unknown mode, force 80x25 color
jnz force3
st80: cmpb $0, adapter # CGA/MDA/HGA => mode 3/7 is always 80x25
jz set80
movb %gs:(0x0484), %al # This is EGA+ -- beware of 80x50 etc.
orb %al, %al # Some buggy BIOS'es set 0 rows
jz set80
cmpb $24, %al # It's hopefully correct
jz set80
#endif /* CONFIG_VIDEO_400_HACK */
force3: DO_STORE
movw $0x0003, %ax # Forced set
int $0x10
set80: stc
ret
# Set the 80x50/80x43 8-pixel mode. Simple BIOS calls.
set_8pixel:
DO_STORE
call use_80x25 # The base is 80x25
set_8pt:
movw $0x1112, %ax # Use 8x8 font
xorb %bl, %bl
int $0x10
movw $0x1200, %ax # Use alternate print screen
movb $0x20, %bl
int $0x10
movw $0x1201, %ax # Turn off cursor emulation
movb $0x34, %bl
int $0x10
movb $0x01, %ah # Define cursor scan lines 6-7
movw $0x0607, %cx
int $0x10
set_current:
stc
ret
# Set the 80x28 mode. This mode works on all VGA's, because it's a standard
# 80x25 mode with 14-point fonts instead of 16-point.
set_80x28:
DO_STORE
call use_80x25 # The base is 80x25
set14: movw $0x1111, %ax # Use 9x14 font
xorb %bl, %bl
int $0x10
movb $0x01, %ah # Define cursor scan lines 11-12
movw $0x0b0c, %cx
int $0x10
stc
ret
# Set the 80x43 mode. This mode is works on all VGA's.
# It's a 350-scanline mode with 8-pixel font.
set_80x43:
DO_STORE
movw $0x1201, %ax # Set 350 scans
movb $0x30, %bl
int $0x10
movw $0x0003, %ax # Reset video mode
int $0x10
jmp set_8pt # Use 8-pixel font
# Set the 80x30 mode (all VGA's). 480 scanlines, 16-pixel font.
set_80x30:
call use_80x25 # Start with real 80x25
DO_STORE
movw $0x3cc, %dx # Get CRTC port
inb %dx, %al
movb $0xd4, %dl
rorb %al # Mono or color?
jc set48a
movb $0xb4, %dl
set48a: movw $0x0c11, %ax # Vertical sync end (also unlocks CR0-7)
call outidx
movw $0x0b06, %ax # Vertical total
call outidx
movw $0x3e07, %ax # (Vertical) overflow
call outidx
movw $0xea10, %ax # Vertical sync start
call outidx
movw $0xdf12, %ax # Vertical display end
call outidx
movw $0xe715, %ax # Vertical blank start
call outidx
movw $0x0416, %ax # Vertical blank end
call outidx
pushw %dx
movb $0xcc, %dl # Misc output register (read)
inb %dx, %al
movb $0xc2, %dl # (write)
andb $0x0d, %al # Preserve clock select bits and color bit
orb $0xe2, %al # Set correct sync polarity
outb %al, %dx
popw %dx
movw $0x501e, force_size
stc # That's all.
ret
# Set the 80x34 mode (all VGA's). 480 scans, 14-pixel font.
set_80x34:
call set_80x30 # Set 480 scans
call set14 # And 14-pt font
movw $0xdb12, %ax # VGA vertical display end
movw $0x5022, force_size
setvde: call outidx
stc
ret
# Set the 80x60 mode (all VGA's). 480 scans, 8-pixel font.
set_80x60:
call set_80x30 # Set 480 scans
call set_8pt # And 8-pt font
movw $0xdf12, %ax # VGA vertical display end
movw $0x503c, force_size
jmp setvde
# Special hack for ThinkPad graphics
set_gfx:
#ifdef CONFIG_VIDEO_GFX_HACK
movw $VIDEO_GFX_BIOS_AX, %ax
movw $VIDEO_GFX_BIOS_BX, %bx
int $0x10
movw $VIDEO_GFX_DUMMY_RESOLUTION, force_size
stc
#endif
ret
#ifdef CONFIG_VIDEO_RETAIN
# Store screen contents to temporary buffer.
store_screen:
cmpb $0, do_restore # Already stored?
jnz stsr
testb $CAN_USE_HEAP, loadflags # Have we space for storing?
jz stsr
pushw %ax
pushw %bx
pushw force_size # Don't force specific size
movw $0, force_size
call mode_params # Obtain params of current mode
popw force_size
movb %fs:(PARAM_VIDEO_LINES), %ah
movb %fs:(PARAM_VIDEO_COLS), %al
movw %ax, %bx # BX=dimensions
mulb %ah
movw %ax, %cx # CX=number of characters
addw %ax, %ax # Calculate image size
addw $modelist+1024+4, %ax
cmpw heap_end_ptr, %ax
jnc sts1 # Unfortunately, out of memory
movw %fs:(PARAM_CURSOR_POS), %ax # Store mode params
leaw modelist+1024, %di
stosw
movw %bx, %ax
stosw
pushw %ds # Store the screen
movw video_segment, %ds
xorw %si, %si
rep
movsw
popw %ds
incb do_restore # Screen will be restored later
sts1: popw %bx
popw %ax
stsr: ret
# Restore screen contents from temporary buffer.
restore_screen:
cmpb $0, do_restore # Has the screen been stored?
jz res1
call mode_params # Get parameters of current mode
movb %fs:(PARAM_VIDEO_LINES), %cl
movb %fs:(PARAM_VIDEO_COLS), %ch
leaw modelist+1024, %si # Screen buffer
lodsw # Set cursor position
movw %ax, %dx
cmpb %cl, %dh
jc res2
movb %cl, %dh
decb %dh
res2: cmpb %ch, %dl
jc res3
movb %ch, %dl
decb %dl
res3: movb $0x02, %ah
movb $0x00, %bh
int $0x10
lodsw # Display size
movb %ah, %dl # DL=number of lines
movb $0, %ah # BX=phys. length of orig. line
movw %ax, %bx
cmpb %cl, %dl # Too many?
jc res4
pushw %ax
movb %dl, %al
subb %cl, %al
mulb %bl
addw %ax, %si
addw %ax, %si
popw %ax
movb %cl, %dl
res4: cmpb %ch, %al # Too wide?
jc res5
movb %ch, %al # AX=width of src. line
res5: movb $0, %cl
xchgb %ch, %cl
movw %cx, %bp # BP=width of dest. line
pushw %es
movw video_segment, %es
xorw %di, %di # Move the data
addw %bx, %bx # Convert BX and BP to _bytes_
addw %bp, %bp
res6: pushw %si
pushw %di
movw %ax, %cx
rep
movsw
popw %di
popw %si
addw %bp, %di
addw %bx, %si
decb %dl
jnz res6
popw %es # Done
res1: ret
#endif /* CONFIG_VIDEO_RETAIN */
# Write to indexed VGA register (AL=index, AH=data, DX=index reg. port)
outidx: outb %al, %dx
pushw %ax
movb %ah, %al
incw %dx
outb %al, %dx
decw %dx
popw %ax
ret
# Build the table of video modes (stored after the setup.S code at the
# `modelist' label. Each video mode record looks like:
# .word MODE-ID (our special mode ID (see above))
# .byte rows (number of rows)
# .byte columns (number of columns)
# Returns address of the end of the table in DI, the end is marked
# with a ASK_VGA ID.
mode_table:
movw mt_end, %di # Already filled?
orw %di, %di
jnz mtab1x
leaw modelist, %di # Store standard modes:
movl $VIDEO_80x25 + 0x50190000, %eax # The 80x25 mode (ALL)
stosl
movb adapter, %al # CGA/MDA/HGA -- no more modes
orb %al, %al
jz mtabe
decb %al
jnz mtabv
movl $VIDEO_8POINT + 0x502b0000, %eax # The 80x43 EGA mode
stosl
jmp mtabe
mtab1x: jmp mtab1
mtabv: leaw vga_modes, %si # All modes for std VGA
movw $vga_modes_end-vga_modes, %cx
rep # I'm unable to use movsw as I don't know how to store a half
movsb # of the expression above to cx without using explicit shr.
cmpb $0, scanning # Mode scan requested?
jz mscan1
call mode_scan
mscan1:
#ifdef CONFIG_VIDEO_LOCAL
call local_modes
#endif /* CONFIG_VIDEO_LOCAL */
#ifdef CONFIG_VIDEO_VESA
call vesa_modes # Detect VESA VGA modes
#endif /* CONFIG_VIDEO_VESA */
#ifdef CONFIG_VIDEO_SVGA
cmpb $0, scanning # Bypass when scanning
jnz mscan2
call svga_modes # Detect SVGA cards & modes
mscan2:
#endif /* CONFIG_VIDEO_SVGA */
mtabe:
#ifdef CONFIG_VIDEO_COMPACT
leaw modelist, %si
movw %di, %dx
movw %si, %di
cmt1: cmpw %dx, %si # Scan all modes
jz cmt2
leaw modelist, %bx # Find in previous entries
movw 2(%si), %cx
cmt3: cmpw %bx, %si
jz cmt4
cmpw 2(%bx), %cx # Found => don't copy this entry
jz cmt5
addw $4, %bx
jmp cmt3
cmt4: movsl # Copy entry
jmp cmt1
cmt5: addw $4, %si # Skip entry
jmp cmt1
cmt2:
#endif /* CONFIG_VIDEO_COMPACT */
movw $ASK_VGA, (%di) # End marker
movw %di, mt_end
mtab1: leaw modelist, %si # SI=mode list, DI=list end
ret0: ret
# Modes usable on all standard VGAs
vga_modes:
.word VIDEO_8POINT
.word 0x5032 # 80x50
.word VIDEO_80x43
.word 0x502b # 80x43
.word VIDEO_80x28
.word 0x501c # 80x28
.word VIDEO_80x30
.word 0x501e # 80x30
.word VIDEO_80x34
.word 0x5022 # 80x34
.word VIDEO_80x60
.word 0x503c # 80x60
#ifdef CONFIG_VIDEO_GFX_HACK
.word VIDEO_GFX_HACK
.word VIDEO_GFX_DUMMY_RESOLUTION
#endif
vga_modes_end:
# Detect VESA modes.
#ifdef CONFIG_VIDEO_VESA
vesa_modes:
cmpb $2, adapter # VGA only
jnz ret0
movw %di, %bp # BP=original mode table end
addw $0x200, %di # Buffer space
movw $0x4f00, %ax # VESA Get card info call
int $0x10
movw %bp, %di
cmpw $0x004f, %ax # Successful?
jnz ret0
cmpw $0x4556, 0x200(%di)
jnz ret0
cmpw $0x4153, 0x202(%di)
jnz ret0
movw $vesa_name, card_name # Set name to "VESA VGA"
pushw %gs
lgsw 0x20e(%di), %si # GS:SI=mode list
movw $128, %cx # Iteration limit
vesa1:
# gas version 2.9.1, using BFD version 2.9.1.0.23 buggers the next inst.
# XXX: lodsw %gs:(%si), %ax # Get next mode in the list
gs; lodsw
cmpw $0xffff, %ax # End of the table?
jz vesar
cmpw $0x0080, %ax # Check validity of mode ID
jc vesa2
orb %ah, %ah # Valid IDs: 0x0000-0x007f/0x0100-0x07ff
jz vesan # Certain BIOSes report 0x80-0xff!
cmpw $0x0800, %ax
jnc vesae
vesa2: pushw %cx
movw %ax, %cx # Get mode information structure
movw $0x4f01, %ax
int $0x10
movw %cx, %bx # BX=mode number
addb $VIDEO_FIRST_VESA>>8, %bh
popw %cx
cmpw $0x004f, %ax
jnz vesan # Don't report errors (buggy BIOSES)
movb (%di), %al # Check capabilities. We require
andb $0x19, %al # a color text mode.
cmpb $0x09, %al
jnz vesan
cmpw $0xb800, 8(%di) # Standard video memory address required
jnz vesan
testb $2, (%di) # Mode characteristics supplied?
movw %bx, (%di) # Store mode number
jz vesa3
xorw %dx, %dx
movw 0x12(%di), %bx # Width
orb %bh, %bh
jnz vesan
movb %bl, 0x3(%di)
movw 0x14(%di), %ax # Height
orb %ah, %ah
jnz vesan
movb %al, 2(%di)
mulb %bl
cmpw $8193, %ax # Small enough for Linux console driver?
jnc vesan
jmp vesaok
vesa3: subw $0x8108, %bx # This mode has no detailed info specified,
jc vesan # so it must be a standard VESA mode.
cmpw $5, %bx
jnc vesan
movw vesa_text_mode_table(%bx), %ax
movw %ax, 2(%di)
vesaok: addw $4, %di # The mode is valid. Store it.
vesan: loop vesa1 # Next mode. Limit exceeded => error
vesae: leaw vesaer, %si
call prtstr
movw %bp, %di # Discard already found modes.
vesar: popw %gs
ret
# Dimensions of standard VESA text modes
vesa_text_mode_table:
.byte 60, 80 # 0108
.byte 25, 132 # 0109
.byte 43, 132 # 010A
.byte 50, 132 # 010B
.byte 60, 132 # 010C
#endif /* CONFIG_VIDEO_VESA */
# Scan for video modes. A bit dirty, but should work.
mode_scan:
movw $0x0100, %cx # Start with mode 0
scm1: movb $0, %ah # Test the mode
movb %cl, %al
int $0x10
movb $0x0f, %ah
int $0x10
cmpb %cl, %al
jnz scm2 # Mode not set
movw $0x3c0, %dx # Test if it's a text mode
movb $0x10, %al # Mode bits
call inidx
andb $0x03, %al
jnz scm2
movb $0xce, %dl # Another set of mode bits
movb $0x06, %al
call inidx
shrb %al
jc scm2
movb $0xd4, %dl # Cursor location
movb $0x0f, %al
call inidx
orb %al, %al
jnz scm2
movw %cx, %ax # Ok, store the mode
stosw
movb %gs:(0x484), %al # Number of rows
incb %al
stosb
movw %gs:(0x44a), %ax # Number of columns
stosb
scm2: incb %cl
jns scm1
movw $0x0003, %ax # Return back to mode 3
int $0x10
ret
tstidx: outw %ax, %dx # OUT DX,AX and inidx
inidx: outb %al, %dx # Read from indexed VGA register
incw %dx # AL=index, DX=index reg port -> AL=data
inb %dx, %al
decw %dx
ret
# Try to detect type of SVGA card and supply (usually approximate) video
# mode table for it.
#ifdef CONFIG_VIDEO_SVGA
svga_modes:
leaw svga_table, %si # Test all known SVGA adapters
dosvga: lodsw
movw %ax, %bp # Default mode table
orw %ax, %ax
jz didsv1
lodsw # Pointer to test routine
pushw %si
pushw %di
pushw %es
movw $0xc000, %bx
movw %bx, %es
call *%ax # Call test routine
popw %es
popw %di
popw %si
orw %bp, %bp
jz dosvga
movw %bp, %si # Found, copy the modes
movb svga_prefix, %ah
cpsvga: lodsb
orb %al, %al
jz didsv
stosw
movsw
jmp cpsvga
didsv: movw %si, card_name # Store pointer to card name
didsv1: ret
# Table of all known SVGA cards. For each card, we store a pointer to
# a table of video modes supported by the card and a pointer to a routine
# used for testing of presence of the card. The video mode table is always
# followed by the name of the card or the chipset.
svga_table:
.word ati_md, ati_test
.word oak_md, oak_test
.word paradise_md, paradise_test
.word realtek_md, realtek_test
.word s3_md, s3_test
.word chips_md, chips_test
.word video7_md, video7_test
.word cirrus5_md, cirrus5_test
.word cirrus6_md, cirrus6_test
.word cirrus1_md, cirrus1_test
.word ahead_md, ahead_test
.word everex_md, everex_test
.word genoa_md, genoa_test
.word trident_md, trident_test
.word tseng_md, tseng_test
.word 0
# Test routines and mode tables:
# S3 - The test algorithm was taken from the SuperProbe package
# for XFree86 1.2.1. Report bugs to Christoph.Niemann@linux.org
s3_test:
movw $0x0f35, %cx # we store some constants in cl/ch
movw $0x03d4, %dx
movb $0x38, %al
call inidx
movb %al, %bh # store current CRT-register 0x38
movw $0x0038, %ax
call outidx # disable writing to special regs
movb %cl, %al # check whether we can write special reg 0x35
call inidx
movb %al, %bl # save the current value of CRT reg 0x35
andb $0xf0, %al # clear bits 0-3
movb %al, %ah
movb %cl, %al # and write it to CRT reg 0x35
call outidx
call inidx # now read it back
andb %ch, %al # clear the upper 4 bits
jz s3_2 # the first test failed. But we have a
movb %bl, %ah # second chance
movb %cl, %al
call outidx
jmp s3_1 # do the other tests
s3_2: movw %cx, %ax # load ah with 0xf and al with 0x35
orb %bl, %ah # set the upper 4 bits of ah with the orig value
call outidx # write ...
call inidx # ... and reread
andb %cl, %al # turn off the upper 4 bits
pushw %ax
movb %bl, %ah # restore old value in register 0x35
movb %cl, %al
call outidx
popw %ax
cmpb %ch, %al # setting lower 4 bits was successful => bad
je no_s3 # writing is allowed => this is not an S3
s3_1: movw $0x4838, %ax # allow writing to special regs by putting
call outidx # magic number into CRT-register 0x38
movb %cl, %al # check whether we can write special reg 0x35
call inidx
movb %al, %bl
andb $0xf0, %al
movb %al, %ah
movb %cl, %al
call outidx
call inidx
andb %ch, %al
jnz no_s3 # no, we can't write => no S3
movw %cx, %ax
orb %bl, %ah
call outidx
call inidx
andb %ch, %al
pushw %ax
movb %bl, %ah # restore old value in register 0x35
movb %cl, %al
call outidx
popw %ax
cmpb %ch, %al
jne no_s31 # writing not possible => no S3
movb $0x30, %al
call inidx # now get the S3 id ...
leaw idS3, %di
movw $0x10, %cx
repne
scasb
je no_s31
movb %bh, %ah
movb $0x38, %al
jmp s3rest
no_s3: movb $0x35, %al # restore CRT register 0x35
movb %bl, %ah
call outidx
no_s31: xorw %bp, %bp # Detection failed
s3rest: movb %bh, %ah
movb $0x38, %al # restore old value of CRT register 0x38
jmp outidx
idS3: .byte 0x81, 0x82, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95
.byte 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa8, 0xb0
s3_md: .byte 0x54, 0x2b, 0x84
.byte 0x55, 0x19, 0x84
.byte 0
.ascii "S3"
.byte 0
# ATI cards.
ati_test:
leaw idati, %si
movw $0x31, %di
movw $0x09, %cx
repe
cmpsb
je atiok
xorw %bp, %bp
atiok: ret
idati: .ascii "761295520"
ati_md: .byte 0x23, 0x19, 0x84
.byte 0x33, 0x2c, 0x84
.byte 0x22, 0x1e, 0x64
.byte 0x21, 0x19, 0x64
.byte 0x58, 0x21, 0x50
.byte 0x5b, 0x1e, 0x50
.byte 0
.ascii "ATI"
.byte 0
# AHEAD
ahead_test:
movw $0x200f, %ax
movw $0x3ce, %dx
outw %ax, %dx
incw %dx
inb %dx, %al
cmpb $0x20, %al
je isahed
cmpb $0x21, %al
je isahed
xorw %bp, %bp
isahed: ret
ahead_md:
.byte 0x22, 0x2c, 0x84
.byte 0x23, 0x19, 0x84
.byte 0x24, 0x1c, 0x84
.byte 0x2f, 0x32, 0xa0
.byte 0x32, 0x22, 0x50
.byte 0x34, 0x42, 0x50
.byte 0
.ascii "Ahead"
.byte 0
# Chips & Tech.
chips_test:
movw $0x3c3, %dx
inb %dx, %al
orb $0x10, %al
outb %al, %dx
movw $0x104, %dx
inb %dx, %al
movb %al, %bl
movw $0x3c3, %dx
inb %dx, %al
andb $0xef, %al
outb %al, %dx
cmpb $0xa5, %bl
je cantok
xorw %bp, %bp
cantok: ret
chips_md:
.byte 0x60, 0x19, 0x84
.byte 0x61, 0x32, 0x84
.byte 0
.ascii "Chips & Technologies"
.byte 0
# Cirrus Logic 5X0
cirrus1_test:
movw $0x3d4, %dx
movb $0x0c, %al
outb %al, %dx
incw %dx
inb %dx, %al
movb %al, %bl
xorb %al, %al
outb %al, %dx
decw %dx
movb $0x1f, %al
outb %al, %dx
incw %dx
inb %dx, %al
movb %al, %bh
xorb %ah, %ah
shlb $4, %al
movw %ax, %cx
movb %bh, %al
shrb $4, %al
addw %ax, %cx
shlw $8, %cx
addw $6, %cx
movw %cx, %ax
movw $0x3c4, %dx
outw %ax, %dx
incw %dx
inb %dx, %al
andb %al, %al
jnz nocirr
movb %bh, %al
outb %al, %dx
inb %dx, %al
cmpb $0x01, %al
je iscirr
nocirr: xorw %bp, %bp
iscirr: movw $0x3d4, %dx
movb %bl, %al
xorb %ah, %ah
shlw $8, %ax
addw $0x0c, %ax
outw %ax, %dx
ret
cirrus1_md:
.byte 0x1f, 0x19, 0x84
.byte 0x20, 0x2c, 0x84
.byte 0x22, 0x1e, 0x84
.byte 0x31, 0x25, 0x64
.byte 0
.ascii "Cirrus Logic 5X0"
.byte 0
# Cirrus Logic 54XX
cirrus5_test:
movw $0x3c4, %dx
movb $6, %al
call inidx
movb %al, %bl # BL=backup
movw $6, %ax
call tstidx
cmpb $0x0f, %al
jne c5fail
movw $0x1206, %ax
call tstidx
cmpb $0x12, %al
jne c5fail
movb $0x1e, %al
call inidx
movb %al, %bh
movb %bh, %ah
andb $0xc0, %ah
movb $0x1e, %al
call tstidx
andb $0x3f, %al
jne c5xx
movb $0x1e, %al
movb %bh, %ah
orb $0x3f, %ah
call tstidx
xorb $0x3f, %al
andb $0x3f, %al
c5xx: pushf
movb $0x1e, %al
movb %bh, %ah
outw %ax, %dx
popf
je c5done
c5fail: xorw %bp, %bp
c5done: movb $6, %al
movb %bl, %ah
outw %ax, %dx
ret
cirrus5_md:
.byte 0x14, 0x19, 0x84
.byte 0x54, 0x2b, 0x84
.byte 0
.ascii "Cirrus Logic 54XX"
.byte 0
# Cirrus Logic 64XX -- no known extra modes, but must be identified, because
# it's misidentified by the Ahead test.
cirrus6_test:
movw $0x3ce, %dx
movb $0x0a, %al
call inidx
movb %al, %bl # BL=backup
movw $0xce0a, %ax
call tstidx
orb %al, %al
jne c2fail
movw $0xec0a, %ax
call tstidx
cmpb $0x01, %al
jne c2fail
movb $0xaa, %al
call inidx # 4X, 5X, 7X and 8X are valid 64XX chip ID's.
shrb $4, %al
subb $4, %al
jz c6done
decb %al
jz c6done
subb $2, %al
jz c6done
decb %al
jz c6done
c2fail: xorw %bp, %bp
c6done: movb $0x0a, %al
movb %bl, %ah
outw %ax, %dx
ret
cirrus6_md:
.byte 0
.ascii "Cirrus Logic 64XX"
.byte 0
# Everex / Trident
everex_test:
movw $0x7000, %ax
xorw %bx, %bx
int $0x10
cmpb $0x70, %al
jne noevrx
shrw $4, %dx
cmpw $0x678, %dx
je evtrid
cmpw $0x236, %dx
jne evrxok
evtrid: leaw trident_md, %bp
evrxok: ret
noevrx: xorw %bp, %bp
ret
everex_md:
.byte 0x03, 0x22, 0x50
.byte 0x04, 0x3c, 0x50
.byte 0x07, 0x2b, 0x64
.byte 0x08, 0x4b, 0x64
.byte 0x0a, 0x19, 0x84
.byte 0x0b, 0x2c, 0x84
.byte 0x16, 0x1e, 0x50
.byte 0x18, 0x1b, 0x64
.byte 0x21, 0x40, 0xa0
.byte 0x40, 0x1e, 0x84
.byte 0
.ascii "Everex/Trident"
.byte 0
# Genoa.
genoa_test:
leaw idgenoa, %si # Check Genoa 'clues'
xorw %ax, %ax
movb %es:(0x37), %al
movw %ax, %di
movw $0x04, %cx
decw %si
decw %di
l1: incw %si
incw %di
movb (%si), %al
testb %al, %al
jz l2
cmpb %es:(%di), %al
l2: loope l1
orw %cx, %cx
je isgen
xorw %bp, %bp
isgen: ret
idgenoa: .byte 0x77, 0x00, 0x99, 0x66
genoa_md:
.byte 0x58, 0x20, 0x50
.byte 0x5a, 0x2a, 0x64
.byte 0x60, 0x19, 0x84
.byte 0x61, 0x1d, 0x84
.byte 0x62, 0x20, 0x84
.byte 0x63, 0x2c, 0x84
.byte 0x64, 0x3c, 0x84
.byte 0x6b, 0x4f, 0x64
.byte 0x72, 0x3c, 0x50
.byte 0x74, 0x42, 0x50
.byte 0x78, 0x4b, 0x64
.byte 0
.ascii "Genoa"
.byte 0
# OAK
oak_test:
leaw idoakvga, %si
movw $0x08, %di
movw $0x08, %cx
repe
cmpsb
je isoak
xorw %bp, %bp
isoak: ret
idoakvga: .ascii "OAK VGA "
oak_md: .byte 0x4e, 0x3c, 0x50
.byte 0x4f, 0x3c, 0x84
.byte 0x50, 0x19, 0x84
.byte 0x51, 0x2b, 0x84
.byte 0
.ascii "OAK"
.byte 0
# WD Paradise.
paradise_test:
leaw idparadise, %si
movw $0x7d, %di
movw $0x04, %cx
repe
cmpsb
je ispara
xorw %bp, %bp
ispara: ret
idparadise: .ascii "VGA="
paradise_md:
.byte 0x41, 0x22, 0x50
.byte 0x47, 0x1c, 0x84
.byte 0x55, 0x19, 0x84
.byte 0x54, 0x2c, 0x84
.byte 0
.ascii "Paradise"
.byte 0
# Trident.
trident_test:
movw $0x3c4, %dx
movb $0x0e, %al
outb %al, %dx
incw %dx
inb %dx, %al
xchgb %al, %ah
xorb %al, %al
outb %al, %dx
inb %dx, %al
xchgb %ah, %al
movb %al, %bl # Strange thing ... in the book this wasn't
andb $0x02, %bl # necessary but it worked on my card which
jz setb2 # is a trident. Without it the screen goes
# blurred ...
andb $0xfd, %al
jmp clrb2
setb2: orb $0x02, %al
clrb2: outb %al, %dx
andb $0x0f, %ah
cmpb $0x02, %ah
je istrid
xorw %bp, %bp
istrid: ret
trident_md:
.byte 0x50, 0x1e, 0x50
.byte 0x51, 0x2b, 0x50
.byte 0x52, 0x3c, 0x50
.byte 0x57, 0x19, 0x84
.byte 0x58, 0x1e, 0x84
.byte 0x59, 0x2b, 0x84
.byte 0x5a, 0x3c, 0x84
.byte 0
.ascii "Trident"
.byte 0
# Tseng.
tseng_test:
movw $0x3cd, %dx
inb %dx, %al # Could things be this simple ! :-)
movb %al, %bl
movb $0x55, %al
outb %al, %dx
inb %dx, %al
movb %al, %ah
movb %bl, %al
outb %al, %dx
cmpb $0x55, %ah
je istsen
isnot: xorw %bp, %bp
istsen: ret
tseng_md:
.byte 0x26, 0x3c, 0x50
.byte 0x2a, 0x28, 0x64
.byte 0x23, 0x19, 0x84
.byte 0x24, 0x1c, 0x84
.byte 0x22, 0x2c, 0x84
.byte 0x21, 0x3c, 0x84
.byte 0
.ascii "Tseng"
.byte 0
# Video7.
video7_test:
movw $0x3cc, %dx
inb %dx, %al
movw $0x3b4, %dx
andb $0x01, %al
jz even7
movw $0x3d4, %dx
even7: movb $0x0c, %al
outb %al, %dx
incw %dx
inb %dx, %al
movb %al, %bl
movb $0x55, %al
outb %al, %dx
inb %dx, %al
decw %dx
movb $0x1f, %al
outb %al, %dx
incw %dx
inb %dx, %al
movb %al, %bh
decw %dx
movb $0x0c, %al
outb %al, %dx
incw %dx
movb %bl, %al
outb %al, %dx
movb $0x55, %al
xorb $0xea, %al
cmpb %bh, %al
jne isnot
movb $VIDEO_FIRST_V7>>8, svga_prefix # Use special mode switching
ret
video7_md:
.byte 0x40, 0x2b, 0x50
.byte 0x43, 0x3c, 0x50
.byte 0x44, 0x3c, 0x64
.byte 0x41, 0x19, 0x84
.byte 0x42, 0x2c, 0x84
.byte 0x45, 0x1c, 0x84
.byte 0
.ascii "Video 7"
.byte 0
# Realtek VGA
realtek_test:
leaw idrtvga, %si
movw $0x45, %di
movw $0x0b, %cx
repe
cmpsb
je isrt
xorw %bp, %bp
isrt: ret
idrtvga: .ascii "REALTEK VGA"
realtek_md:
.byte 0x1a, 0x3c, 0x50
.byte 0x1b, 0x19, 0x84
.byte 0x1c, 0x1e, 0x84
.byte 0x1d, 0x2b, 0x84
.byte 0x1e, 0x3c, 0x84
.byte 0
.ascii "REALTEK"
.byte 0
#endif /* CONFIG_VIDEO_SVGA */
# User-defined local mode table (VGA only)
#ifdef CONFIG_VIDEO_LOCAL
local_modes:
leaw local_mode_table, %si
locm1: lodsw
orw %ax, %ax
jz locm2
stosw
movsw
jmp locm1
locm2: ret
# This is the table of local video modes which can be supplied manually
# by the user. Each entry consists of mode ID (word) and dimensions
# (byte for column count and another byte for row count). These modes
# are placed before all SVGA and VESA modes and override them if table
# compacting is enabled. The table must end with a zero word followed
# by NUL-terminated video adapter name.
local_mode_table:
.word 0x0100 # Example: 40x25
.byte 25,40
.word 0
.ascii "Local"
.byte 0
#endif /* CONFIG_VIDEO_LOCAL */
# Read a key and return the ASCII code in al, scan code in ah
getkey: xorb %ah, %ah
int $0x16
ret
# Read a key with a timeout of 30 seconds.
# The hardware clock is used to get the time.
getkt: call gettime
addb $30, %al # Wait 30 seconds
cmpb $60, %al
jl lminute
subb $60, %al
lminute:
movb %al, %cl
again: movb $0x01, %ah
int $0x16
jnz getkey # key pressed, so get it
call gettime
cmpb %cl, %al
jne again
movb $0x20, %al # timeout, return `space'
ret
# Flush the keyboard buffer
flush: movb $0x01, %ah
int $0x16
jz empty
xorb %ah, %ah
int $0x16
jmp flush
empty: ret
# Print hexadecimal number.
prthw: pushw %ax
movb %ah, %al
call prthb
popw %ax
prthb: pushw %ax
shrb $4, %al
call prthn
popw %ax
andb $0x0f, %al
prthn: cmpb $0x0a, %al
jc prth1
addb $0x07, %al
prth1: addb $0x30, %al
jmp prtchr
# Print decimal number in al
prtdec: pushw %ax
pushw %cx
xorb %ah, %ah
movb $0x0a, %cl
idivb %cl
cmpb $0x09, %al
jbe lt100
call prtdec
jmp skip10
lt100: addb $0x30, %al
call prtchr
skip10: movb %ah, %al
addb $0x30, %al
call prtchr
popw %cx
popw %ax
ret
store_edid:
pushw %es # just save all registers
pushw %ax
pushw %bx
pushw %cx
pushw %dx
pushw %di
pushw %fs
popw %es
movl $0x13131313, %eax # memset block with 0x13
movw $32, %cx
movw $0x140, %di
cld
rep
stosl
movw $0x4f15, %ax # do VBE/DDC
movw $0x01, %bx
movw $0x00, %cx
movw $0x01, %dx
movw $0x140, %di
int $0x10
popw %di # restore all registers
popw %dx
popw %cx
popw %bx
popw %ax
popw %es
ret
# VIDEO_SELECT-only variables
mt_end: .word 0 # End of video mode table if built
edit_buf: .space 6 # Line editor buffer
card_name: .word 0 # Pointer to adapter name
scanning: .byte 0 # Performing mode scan
do_restore: .byte 0 # Screen contents altered during mode change
svga_prefix: .byte VIDEO_FIRST_BIOS>>8 # Default prefix for BIOS modes
graphic_mode: .byte 0 # Graphic mode with a linear frame buffer
dac_size: .byte 6 # DAC bit depth
# Status messages
keymsg: .ascii "Press <RETURN> to see video modes available, "
.ascii "<SPACE> to continue or wait 30 secs"
.byte 0x0d, 0x0a, 0
listhdr: .byte 0x0d, 0x0a
.ascii "Mode: COLSxROWS:"
crlft: .byte 0x0d, 0x0a, 0
prompt: .byte 0x0d, 0x0a
.asciz "Enter mode number or `scan': "
unknt: .asciz "Unknown mode ID. Try again."
badmdt: .ascii "You passed an undefined mode number."
.byte 0x0d, 0x0a, 0
vesaer: .ascii "Error: Scanning of VESA modes failed. Please "
.ascii "report to <mj@ucw.cz>."
.byte 0x0d, 0x0a, 0
old_name: .asciz "CGA/MDA/HGA"
ega_name: .asciz "EGA"
svga_name: .ascii " "
vga_name: .asciz "VGA"
vesa_name: .asciz "VESA"
name_bann: .asciz "Video adapter: "
#endif /* CONFIG_VIDEO_SELECT */
# Other variables:
adapter: .byte 0 # Video adapter: 0=CGA/MDA/HGA,1=EGA,2=VGA
video_segment: .word 0xb800 # Video memory segment
force_size: .word 0 # Use this size instead of the one in BIOS vars