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Commit cf06de7b authored by H. Peter Anvin's avatar H. Peter Anvin Committed by H. Peter Anvin
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x86, setup: "glove box" BIOS interrupts in the video code 

Impact: BIOS proofing

"Glove box" off BIOS interrupts in the video code.

LKML-Reference: <49DE7F79.4030106@zytor.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
parent 0a706db3
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Showing with 151 additions and 164 deletions
arch/x86/boot/video-bios.c
View file @ cf06de7b
......@@ -2,6 +2,7 @@
*
* 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.
......@@ -29,21 +30,21 @@ static int bios_set_mode(struct mode_info *mi)
static int set_bios_mode(u8 mode)
{
u16 ax;
struct biosregs ireg, oreg;
u8 new_mode;
ax = mode; /* AH=0x00 Set Video Mode */
asm volatile(INT10
: "+a" (ax)
: : "ebx", "ecx", "edx", "esi", "edi");
initregs(&ireg);
ireg.al = mode; /* AH=0x00 Set Video Mode */
intcall(0x10, &ireg, NULL);
ax = 0x0f00; /* Get Current Video Mode */
asm volatile(INT10
: "+a" (ax)
: : "ebx", "ecx", "edx", "esi", "edi");
ireg.ah = 0x0f; /* Get Current Video Mode */
intcall(0x10, &ireg, &oreg);
do_restore = 1; /* Assume video contents were lost */
new_mode = ax & 0x7f; /* Not all BIOSes are clean with the top bit */
/* Not all BIOSes are clean with the top bit */
new_mode = ireg.al & 0x7f;
if (new_mode == mode)
return 0; /* Mode change OK */
......@@ -53,10 +54,8 @@ static int set_bios_mode(u8 mode)
/* Mode setting failed, but we didn't end up where we
started. That's bad. Try to revert to the original
video mode. */
ax = boot_params.screen_info.orig_video_mode;
asm volatile(INT10
: "+a" (ax)
: : "ebx", "ecx", "edx", "esi", "edi");
ireg.ax = boot_params.screen_info.orig_video_mode;
intcall(0x10, &ireg, NULL);
}
#endif
return -1;
......
arch/x86/boot/video-vesa.c
View file @ cf06de7b
......@@ -2,6 +2,7 @@
*
* 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.
......@@ -31,7 +32,7 @@ static inline void vesa_store_mode_params_graphics(void) {}
static int vesa_probe(void)
{
#if defined(CONFIG_VIDEO_VESA) || defined(CONFIG_FIRMWARE_EDID)
u16 ax, cx, di;
struct biosregs ireg, oreg;
u16 mode;
addr_t mode_ptr;
struct mode_info *mi;
......@@ -39,13 +40,12 @@ static int vesa_probe(void)
video_vesa.modes = GET_HEAP(struct mode_info, 0);
ax = 0x4f00;
di = (size_t)&vginfo;
asm(INT10
: "+a" (ax), "+D" (di), "=m" (vginfo)
: : "ebx", "ecx", "edx", "esi");
initregs(&ireg);
ireg.ax = 0x4f00;
ireg.di = (size_t)&vginfo;
intcall(0x10, &ireg, &oreg);
if (ax != 0x004f ||
if (ireg.ax != 0x004f ||
vginfo.signature != VESA_MAGIC ||
vginfo.version < 0x0102)
return 0; /* Not present */
......@@ -65,14 +65,12 @@ static int vesa_probe(void)
memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
ax = 0x4f01;
cx = mode;
di = (size_t)&vminfo;
asm(INT10
: "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
: : "ebx", "edx", "esi");
ireg.ax = 0x4f01;
ireg.cx = mode;
ireg.di = (size_t)&vminfo;
intcall(0x10, &ireg, &oreg);
if (ax != 0x004f)
if (ireg.ax != 0x004f)
continue;
if ((vminfo.mode_attr & 0x15) == 0x05) {
......@@ -111,20 +109,19 @@ static int vesa_probe(void)
static int vesa_set_mode(struct mode_info *mode)
{
u16 ax, bx, cx, di;
struct biosregs ireg, oreg;
int is_graphic;
u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
ax = 0x4f01;
cx = vesa_mode;
di = (size_t)&vminfo;
asm(INT10
: "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
: : "ebx", "edx", "esi");
initregs(&ireg);
ireg.ax = 0x4f01;
ireg.cx = vesa_mode;
ireg.di = (size_t)&vminfo;
intcall(0x10, &ireg, &oreg);
if (ax != 0x004f)
if (oreg.ax != 0x004f)
return -1;
if ((vminfo.mode_attr & 0x15) == 0x05) {
......@@ -141,14 +138,12 @@ static int vesa_set_mode(struct mode_info *mode)
}
ax = 0x4f02;
bx = vesa_mode;
di = 0;
asm volatile(INT10
: "+a" (ax), "+b" (bx), "+D" (di)
: : "ecx", "edx", "esi");
initregs(&ireg);
ireg.ax = 0x4f02;
ireg.bx = vesa_mode;
intcall(0x10, &ireg, &oreg);
if (ax != 0x004f)
if (oreg.ax != 0x004f)
return -1;
graphic_mode = is_graphic;
......@@ -171,50 +166,45 @@ static int vesa_set_mode(struct mode_info *mode)
/* Switch DAC to 8-bit mode */
static void vesa_dac_set_8bits(void)
{
struct biosregs ireg, oreg;
u8 dac_size = 6;
/* If possible, switch the DAC to 8-bit mode */
if (vginfo.capabilities & 1) {
u16 ax, bx;
ax = 0x4f08;
bx = 0x0800;
asm volatile(INT10
: "+a" (ax), "+b" (bx)
: : "ecx", "edx", "esi", "edi");
if (ax == 0x004f)
dac_size = bx >> 8;
initregs(&ireg);
ireg.ax = 0x4f08;
ireg.bh = 0x08;
intcall(0x10, &ireg, &oreg);
if (oreg.ax == 0x004f)
dac_size = oreg.bh;
}
/* Set the color sizes to the DAC size, and offsets to 0 */
boot_params.screen_info.red_size = dac_size;
boot_params.screen_info.red_size = dac_size;
boot_params.screen_info.green_size = dac_size;
boot_params.screen_info.blue_size = dac_size;
boot_params.screen_info.rsvd_size = dac_size;
boot_params.screen_info.blue_size = dac_size;
boot_params.screen_info.rsvd_size = dac_size;
boot_params.screen_info.red_pos = 0;
boot_params.screen_info.green_pos = 0;
boot_params.screen_info.blue_pos = 0;
boot_params.screen_info.rsvd_pos = 0;
boot_params.screen_info.red_pos = 0;
boot_params.screen_info.green_pos = 0;
boot_params.screen_info.blue_pos = 0;
boot_params.screen_info.rsvd_pos = 0;
}
/* Save the VESA protected mode info */
static void vesa_store_pm_info(void)
{
u16 ax, bx, di, es;
struct biosregs ireg, oreg;
ax = 0x4f0a;
bx = di = 0;
asm("pushw %%es; "INT10"; movw %%es,%0; popw %%es"
: "=d" (es), "+a" (ax), "+b" (bx), "+D" (di)
: : "ecx", "esi");
initregs(&ireg);
ireg.ax = 0x4f0a;
intcall(0x10, &ireg, &oreg);
if (ax != 0x004f)
if (oreg.ax != 0x004f)
return;
boot_params.screen_info.vesapm_seg = es;
boot_params.screen_info.vesapm_off = di;
boot_params.screen_info.vesapm_seg = oreg.es;
boot_params.screen_info.vesapm_off = oreg.di;
}
/*
......@@ -252,7 +242,7 @@ static void vesa_store_mode_params_graphics(void)
void vesa_store_edid(void)
{
#ifdef CONFIG_FIRMWARE_EDID
u16 ax, bx, cx, dx, di;
struct biosregs ireg, oreg;
/* Apparently used as a nonsense token... */
memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);
......@@ -260,33 +250,26 @@ void vesa_store_edid(void)
if (vginfo.version < 0x0200)
return; /* EDID requires VBE 2.0+ */
ax = 0x4f15; /* VBE DDC */
bx = 0x0000; /* Report DDC capabilities */
cx = 0; /* Controller 0 */
di = 0; /* ES:DI must be 0 by spec */
/* Note: The VBE DDC spec is different from the main VESA spec;
we genuinely have to assume all registers are destroyed here. */
asm("pushw %%es; movw %2,%%es; "INT10"; popw %%es"
: "+a" (ax), "+b" (bx), "+c" (cx), "+D" (di)
: : "esi", "edx");
initregs(&ireg);
ireg.ax = 0x4f15; /* VBE DDC */
/* ireg.bx = 0x0000; */ /* Report DDC capabilities */
/* ireg.cx = 0; */ /* Controller 0 */
ireg.es = 0; /* ES:DI must be 0 by spec */
intcall(0x10, &ireg, &oreg);
if (ax != 0x004f)
if (oreg.ax != 0x004f)
return; /* No EDID */
/* BH = time in seconds to transfer EDD information */
/* BL = DDC level supported */
ax = 0x4f15; /* VBE DDC */
bx = 0x0001; /* Read EDID */
cx = 0; /* Controller 0 */
dx = 0; /* EDID block number */
di =(size_t) &boot_params.edid_info; /* (ES:)Pointer to block */
asm(INT10
: "+a" (ax), "+b" (bx), "+d" (dx), "=m" (boot_params.edid_info),
"+c" (cx), "+D" (di)
: : "esi");
ireg.ax = 0x4f15; /* VBE DDC */
ireg.bx = 0x0001; /* Read EDID */
/* ireg.cx = 0; */ /* Controller 0 */
/* ireg.dx = 0; */ /* EDID block number */
ireg.es = ds();
ireg.di =(size_t)&boot_params.edid_info; /* (ES:)Pointer to block */
intcall(0x10, &ireg, &oreg);
#endif /* CONFIG_FIRMWARE_EDID */
}
......
arch/x86/boot/video-vga.c
View file @ cf06de7b
......@@ -2,6 +2,7 @@
*
* 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.
......@@ -39,30 +40,30 @@ static __videocard video_vga;
/* Set basic 80x25 mode */
static u8 vga_set_basic_mode(void)
{
struct biosregs ireg, oreg;
u16 ax;
u8 rows;
u8 mode;
initregs(&ireg);
#ifdef CONFIG_VIDEO_400_HACK
if (adapter >= ADAPTER_VGA) {
asm volatile(INT10
: : "a" (0x1202), "b" (0x0030)
: "ecx", "edx", "esi", "edi");
ireg.ax = 0x1202;
ireg.bx = 0x0030;
intcall(0x10, &ireg, NULL);
}
#endif
ax = 0x0f00;
asm volatile(INT10
: "+a" (ax)
: : "ebx", "ecx", "edx", "esi", "edi");
mode = (u8)ax;
intcall(0x10, &ireg, &oreg);
mode = oreg.al;
set_fs(0);
rows = rdfs8(0x484); /* rows minus one */
#ifndef CONFIG_VIDEO_400_HACK
if ((ax == 0x5003 || ax == 0x5007) &&
if ((oreg.ax == 0x5003 || oreg.ax == 0x5007) &&
(rows == 0 || rows == 24))
return mode;
#endif
......@@ -71,10 +72,8 @@ static u8 vga_set_basic_mode(void)
mode = 3;
/* Set the mode */
ax = mode;
asm volatile(INT10
: "+a" (ax)
: : "ebx", "ecx", "edx", "esi", "edi");
ireg.ax = mode; /* AH=0: set mode */
intcall(0x10, &ireg, NULL);
do_restore = 1;
return mode;
}
......@@ -82,43 +81,69 @@ static u8 vga_set_basic_mode(void)
static void vga_set_8font(void)
{
/* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
struct biosregs ireg;
initregs(&ireg);
/* Set 8x8 font */
asm volatile(INT10 : : "a" (0x1112), "b" (0));
ireg.ax = 0x1112;
/* ireg.bl = 0; */
intcall(0x10, &ireg, NULL);
/* Use alternate print screen */
asm volatile(INT10 : : "a" (0x1200), "b" (0x20));
ireg.ax = 0x1200;
ireg.bl = 0x20;
intcall(0x10, &ireg, NULL);
/* Turn off cursor emulation */
asm volatile(INT10 : : "a" (0x1201), "b" (0x34));
ireg.ax = 0x1201;
ireg.bl = 0x34;
intcall(0x10, &ireg, NULL);
/* Cursor is scan lines 6-7 */
asm volatile(INT10 : : "a" (0x0100), "c" (0x0607));
ireg.ax = 0x0100;
ireg.cx = 0x0607;
intcall(0x10, &ireg, NULL);
}
static void vga_set_14font(void)
{
/* Set 9x14 font - 80x28 on VGA */
struct biosregs ireg;
initregs(&ireg);
/* Set 9x14 font */
asm volatile(INT10 : : "a" (0x1111), "b" (0));
ireg.ax = 0x1111;
/* ireg.bl = 0; */
intcall(0x10, &ireg, NULL);
/* Turn off cursor emulation */
asm volatile(INT10 : : "a" (0x1201), "b" (0x34));
ireg.ax = 0x1201;
ireg.bl = 0x34;
intcall(0x10, &ireg, NULL);
/* Cursor is scan lines 11-12 */
asm volatile(INT10 : : "a" (0x0100), "c" (0x0b0c));
ireg.ax = 0x0100;
ireg.cx = 0x0b0c;
intcall(0x10, &ireg, NULL);
}
static void vga_set_80x43(void)
{
/* Set 80x43 mode on VGA (not EGA) */
struct biosregs ireg;
initregs(&ireg);
/* Set 350 scans */
asm volatile(INT10 : : "a" (0x1201), "b" (0x30));
ireg.ax = 0x1201;
ireg.bl = 0x30;
intcall(0x10, &ireg, NULL);
/* Reset video mode */
asm volatile(INT10 : : "a" (0x0003));
ireg.ax = 0x0003;
intcall(0x10, &ireg, NULL);
vga_set_8font();
}
......@@ -225,8 +250,6 @@ static int vga_set_mode(struct mode_info *mode)
*/
static int vga_probe(void)
{
u16 ega_bx;
static const char *card_name[] = {
"CGA/MDA/HGC", "EGA", "VGA"
};
......@@ -240,26 +263,26 @@ static int vga_probe(void)
sizeof(ega_modes)/sizeof(struct mode_info),
sizeof(vga_modes)/sizeof(struct mode_info),
};
u8 vga_flag;
asm(INT10
: "=b" (ega_bx)
: "a" (0x1200), "b" (0x10) /* Check EGA/VGA */
: "ecx", "edx", "esi", "edi");
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ax = 0x1200;
ireg.bl = 0x10; /* Check EGA/VGA */
intcall(0x10, &ireg, &oreg);
#ifndef _WAKEUP
boot_params.screen_info.orig_video_ega_bx = ega_bx;
boot_params.screen_info.orig_video_ega_bx = oreg.bx;
#endif
/* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
if ((u8)ega_bx != 0x10) {
if (oreg.bl != 0x10) {
/* EGA/VGA */
asm(INT10
: "=a" (vga_flag)
: "a" (0x1a00)
: "ebx", "ecx", "edx", "esi", "edi");
ireg.ax = 0x1a00;
intcall(0x10, &ireg, &oreg);
if (vga_flag == 0x1a) {
if (oreg.al == 0x1a) {
adapter = ADAPTER_VGA;
#ifndef _WAKEUP
boot_params.screen_info.orig_video_isVGA = 1;
......
arch/x86/boot/video.c
View file @ cf06de7b
......@@ -2,6 +2,7 @@
*
* 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.
......@@ -18,33 +19,29 @@
static void store_cursor_position(void)
{
u16 curpos;
u16 ax, bx;
struct biosregs ireg, oreg;
ax = 0x0300;
bx = 0;
asm(INT10
: "=d" (curpos), "+a" (ax), "+b" (bx)
: : "ecx", "esi", "edi");
initregs(&ireg);
ireg.ah = 0x03;
intcall(0x10, &ireg, &oreg);
boot_params.screen_info.orig_x = curpos;
boot_params.screen_info.orig_y = curpos >> 8;
boot_params.screen_info.orig_x = oreg.dl;
boot_params.screen_info.orig_y = oreg.dh;
}
static void store_video_mode(void)
{
u16 ax, page;
struct biosregs ireg, oreg;
/* N.B.: the saving of the video page here is a bit silly,
since we pretty much assume page 0 everywhere. */
ax = 0x0f00;
asm(INT10
: "+a" (ax), "=b" (page)
: : "ecx", "edx", "esi", "edi");
initregs(&ireg);
ireg.ah = 0x0f;
intcall(0x10, &ireg, &oreg);
/* Not all BIOSes are clean with respect to the top bit */
boot_params.screen_info.orig_video_mode = ax & 0x7f;
boot_params.screen_info.orig_video_page = page >> 8;
boot_params.screen_info.orig_video_mode = oreg.al & 0x7f;
boot_params.screen_info.orig_video_page = oreg.bh;
}
/*
......@@ -257,7 +254,7 @@ static void restore_screen(void)
int y;
addr_t dst = 0;
u16 *src = saved.data;
u16 ax, bx, dx;
struct biosregs ireg;
if (graphic_mode)
return; /* Can't restore onto a graphic mode */
......@@ -296,12 +293,11 @@ static void restore_screen(void)
}
/* Restore cursor position */
ax = 0x0200; /* Set cursor position */
bx = 0; /* Page number (<< 8) */
dx = (saved.cury << 8)+saved.curx;
asm volatile(INT10
: "+a" (ax), "+b" (bx), "+d" (dx)
: : "ecx", "esi", "edi");
initregs(&ireg);
ireg.ah = 0x02; /* Set cursor position */
ireg.dh = saved.cury;
ireg.dl = saved.curx;
intcall(0x10, &ireg, NULL);
}
#else
#define save_screen() ((void)0)
......
arch/x86/boot/video.h
View file @ cf06de7b
......@@ -112,20 +112,6 @@ extern int force_x, force_y; /* Don't query the BIOS for cols/rows */
extern int do_restore; /* Restore screen contents */
extern int graphic_mode; /* Graphics mode with linear frame buffer */
/*
* int $0x10 is notorious for touching registers it shouldn't.
* gcc doesn't like %ebp being clobbered, so define it as a push/pop
* sequence here.
*
* A number of systems, including the original PC can clobber %bp in
* certain circumstances, like when scrolling. There exists at least
* one Trident video card which could clobber DS under a set of
* circumstances that we are unlikely to encounter (scrolling when
* using an extended graphics mode of more than 800x600 pixels), but
* it's cheap insurance to deal with that here.
*/
#define INT10 "pushl %%ebp; pushw %%ds; int $0x10; popw %%ds; popl %%ebp"
/* Accessing VGA indexed registers */
static inline u8 in_idx(u16 port, u8 index)
{
......
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