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: H. Peter Anvin <hpa@linux.intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/arch/x86/boot/video-vesa.c b/arch/x86/boot/video-vesa.c
index 4a58c8c..c700147 100644
--- a/arch/x86/boot/video-vesa.c
+++ b/arch/x86/boot/video-vesa.c
@@ -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 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 @@
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 @@
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_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 @@
}
- 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 @@
/* 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 @@
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 @@
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 */
+ 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);
- /* 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");
-
- 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 */
}