mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-10-31 06:18:54 +00:00
febe04de3b
Some intcall() misuses the input biosregs as output in
cf06de7b9c
This fixes the problem vga=ask boot option doesn't show enough modes.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090701021307.GA3127@localhost.localdomain>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
129 lines
2.8 KiB
C
129 lines
2.8 KiB
C
/* -*- linux-c -*- ------------------------------------------------------- *
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright 2007 rPath, Inc. - All Rights Reserved
|
|
* Copyright 2009 Intel Corporation; author H. Peter Anvin
|
|
*
|
|
* This file is part of the Linux kernel, and is made available under
|
|
* the terms of the GNU General Public License version 2.
|
|
*
|
|
* ----------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Standard video BIOS modes
|
|
*
|
|
* We have two options for this; silent and scanned.
|
|
*/
|
|
|
|
#include "boot.h"
|
|
#include "video.h"
|
|
|
|
static __videocard video_bios;
|
|
|
|
/* Set a conventional BIOS mode */
|
|
static int set_bios_mode(u8 mode);
|
|
|
|
static int bios_set_mode(struct mode_info *mi)
|
|
{
|
|
return set_bios_mode(mi->mode - VIDEO_FIRST_BIOS);
|
|
}
|
|
|
|
static int set_bios_mode(u8 mode)
|
|
{
|
|
struct biosregs ireg, oreg;
|
|
u8 new_mode;
|
|
|
|
initregs(&ireg);
|
|
ireg.al = mode; /* AH=0x00 Set Video Mode */
|
|
intcall(0x10, &ireg, NULL);
|
|
|
|
ireg.ah = 0x0f; /* Get Current Video Mode */
|
|
intcall(0x10, &ireg, &oreg);
|
|
|
|
do_restore = 1; /* Assume video contents were lost */
|
|
|
|
/* Not all BIOSes are clean with the top bit */
|
|
new_mode = oreg.al & 0x7f;
|
|
|
|
if (new_mode == mode)
|
|
return 0; /* Mode change OK */
|
|
|
|
#ifndef _WAKEUP
|
|
if (new_mode != boot_params.screen_info.orig_video_mode) {
|
|
/* Mode setting failed, but we didn't end up where we
|
|
started. That's bad. Try to revert to the original
|
|
video mode. */
|
|
ireg.ax = boot_params.screen_info.orig_video_mode;
|
|
intcall(0x10, &ireg, NULL);
|
|
}
|
|
#endif
|
|
return -1;
|
|
}
|
|
|
|
static int bios_probe(void)
|
|
{
|
|
u8 mode;
|
|
#ifdef _WAKEUP
|
|
u8 saved_mode = 0x03;
|
|
#else
|
|
u8 saved_mode = boot_params.screen_info.orig_video_mode;
|
|
#endif
|
|
u16 crtc;
|
|
struct mode_info *mi;
|
|
int nmodes = 0;
|
|
|
|
if (adapter != ADAPTER_EGA && adapter != ADAPTER_VGA)
|
|
return 0;
|
|
|
|
set_fs(0);
|
|
crtc = vga_crtc();
|
|
|
|
video_bios.modes = GET_HEAP(struct mode_info, 0);
|
|
|
|
for (mode = 0x14; mode <= 0x7f; mode++) {
|
|
if (!heap_free(sizeof(struct mode_info)))
|
|
break;
|
|
|
|
if (mode_defined(VIDEO_FIRST_BIOS+mode))
|
|
continue;
|
|
|
|
if (set_bios_mode(mode))
|
|
continue;
|
|
|
|
/* Try to verify that it's a text mode. */
|
|
|
|
/* Attribute Controller: make graphics controller disabled */
|
|
if (in_idx(0x3c0, 0x10) & 0x01)
|
|
continue;
|
|
|
|
/* Graphics Controller: verify Alpha addressing enabled */
|
|
if (in_idx(0x3ce, 0x06) & 0x01)
|
|
continue;
|
|
|
|
/* CRTC cursor location low should be zero(?) */
|
|
if (in_idx(crtc, 0x0f))
|
|
continue;
|
|
|
|
mi = GET_HEAP(struct mode_info, 1);
|
|
mi->mode = VIDEO_FIRST_BIOS+mode;
|
|
mi->depth = 0; /* text */
|
|
mi->x = rdfs16(0x44a);
|
|
mi->y = rdfs8(0x484)+1;
|
|
nmodes++;
|
|
}
|
|
|
|
set_bios_mode(saved_mode);
|
|
|
|
return nmodes;
|
|
}
|
|
|
|
static __videocard video_bios =
|
|
{
|
|
.card_name = "BIOS",
|
|
.probe = bios_probe,
|
|
.set_mode = bios_set_mode,
|
|
.unsafe = 1,
|
|
.xmode_first = VIDEO_FIRST_BIOS,
|
|
.xmode_n = 0x80,
|
|
};
|