/* -*- linux-c -*- ------------------------------------------------------- *
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright 2007 rPath, Inc. - All Rights Reserved
*
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
*
* ----------------------------------------------------------------------- */
/*
* arch/i386/boot/video-vga.c
*
* Common all-VGA modes
*/
#include "boot.h"
#include "video.h"
static struct mode_info vga_modes[] = {
{ VIDEO_80x25, 80, 25, 0 },
{ VIDEO_8POINT, 80, 50, 0 },
{ VIDEO_80x43, 80, 43, 0 },
{ VIDEO_80x28, 80, 28, 0 },
{ VIDEO_80x30, 80, 30, 0 },
{ VIDEO_80x34, 80, 34, 0 },
{ VIDEO_80x60, 80, 60, 0 },
};
static struct mode_info ega_modes[] = {
{ VIDEO_80x25, 80, 25, 0 },
{ VIDEO_8POINT, 80, 43, 0 },
};
static struct mode_info cga_modes[] = {
{ VIDEO_80x25, 80, 25, 0 },
};
__videocard video_vga;
/* Set basic 80x25 mode */
static u8 vga_set_basic_mode(void)
{
u16 ax;
u8 rows;
u8 mode;
#ifdef CONFIG_VIDEO_400_HACK
if (adapter >= ADAPTER_VGA) {
asm volatile(INT10
: : "a" (0x1202), "b" (0x0030)
: "ecx", "edx", "esi", "edi");
}
#endif
ax = 0x0f00;
asm volatile(INT10
: "+a" (ax)
: : "ebx", "ecx", "edx", "esi", "edi");
mode = (u8)ax;
set_fs(0);
rows = rdfs8(0x484); /* rows minus one */
#ifndef CONFIG_VIDEO_400_HACK
if ((ax == 0x5003 || ax == 0x5007) &&
(rows == 0 || rows == 24))
return mode;
#endif
if (mode != 3 && mode != 7)
mode = 3;
/* Set the mode */
ax = mode;
asm volatile(INT10
: "+a" (ax)
: : "ebx", "ecx", "edx", "esi", "edi");
do_restore = 1;
return mode;
}
static void vga_set_8font(void)
{
/* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
/* Set 8x8 font */
asm volatile(INT10 : : "a" (0x1112), "b" (0));
/* Use alternate print screen */
asm volatile(INT10 : : "a" (0x1200), "b" (0x20));
/* Turn off cursor emulation */
asm volatile(INT10 : : "a" (0x1201), "b" (0x34));
/* Cursor is scan lines 6-7 */
asm volatile(INT10 : : "a" (0x0100), "c" (0x0607));
}
static void vga_set_14font(void)
{
/* Set 9x14 font - 80x28 on VGA */
/* Set 9x14 font */
asm volatile(INT10 : : "a" (0x1111), "b" (0));
/* Turn off cursor emulation */
asm volatile(INT10 : : "a" (0x1201), "b" (0x34));
/* Cursor is scan lines 11-12 */
asm volatile(INT10 : : "a" (0x0100), "c" (0x0b0c));
}
static void vga_set_80x43(void)
{
/* Set 80x43 mode on VGA (not EGA) */
/* Set 350 scans */
asm volatile(INT10 : : "a" (0x1201), "b" (0x30));
/* Reset video mode */
asm volatile(INT10 : : "a" (0x0003));
vga_set_8font();
}
/* I/O address of the VGA CRTC */
u16 vga_crtc(void)
{
return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
}
static void vga_set_480_scanlines(int end)
{
u16 crtc;
u8 csel;
crtc = vga_crtc();
out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
out_idx(0x0b, crtc, 0x06); /* Vertical total */
out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
out_idx(0xea, crtc, 0x10); /* Vertical sync start */
out_idx(end, crtc, 0x12); /* Vertical display end */
out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
out_idx(0x04, crtc, 0x16); /* Vertical blank end */
csel = inb(0x3cc);
csel &= 0x0d;
csel |= 0xe2;
outb(csel, 0x3cc);
}
static void vga_set_80x30(void)
{
vga_set_480_scanlines(0xdf);
}
static void vga_set_80x34(void)
{
vga_set_14font();
vga_set_480_scanlines(0xdb);
}
static void vga_set_80x60(void)
{
vga_set_8font();
vga_set_480_scanlines(0xdf);
}
static int vga_set_mode(struct mode_info *mode)
{
/* Set the basic mode */
vga_set_basic_mode();
/* Override a possibly broken BIOS */
force_x = mode->x;
force_y = mode->y;
switch (mode->mode) {
case VIDEO_80x25:
break;
case VIDEO_8POINT:
vga_set_8font();
break;
case VIDEO_80x43:
vga_set_80x43();
break;
case VIDEO_80x28:
vga_set_14font();
break;
case VIDEO_80x30:
vga_set_80x30();
break;
case VIDEO_80x34:
vga_set_80x34();
break;
case VIDEO_80x60:
vga_set_80x60();
break;
}
return 0;
}
/*
* Note: this probe includes basic information required by all
* systems. It should be executed first, by making sure
* video-vga.c is listed first in the Makefile.
*/
static int vga_probe(void)
{
static const char *card_name[] = {
"CGA/MDA/HGC", "EGA", "VGA"
};
static struct mode_info *mode_lists[] = {
cga_modes,
ega_modes,
vga_modes,
};
static int mode_count[] = {
sizeof(cga_modes)/sizeof(struct mode_info),
sizeof(ega_modes)/sizeof(struct mode_info),
sizeof(vga_modes)/sizeof(struct mode_info),
};
u8 vga_flag;
asm(INT10
: "=b" (boot_params.screen_info.orig_video_ega_bx)
: "a" (0x1200), "b" (0x10) /* Check EGA/VGA */
: "ecx", "edx", "esi", "edi");
/* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
if ((u8)boot_params.screen_info.orig_video_ega_bx != 0x10) {
/* EGA/VGA */
asm(INT10
: "=a" (vga_flag)
: "a" (0x1a00)
: "ebx", "ecx", "edx", "esi", "edi");
if (vga_flag == 0x1a) {
adapter = ADAPTER_VGA;
boot_params.screen_info.orig_video_isVGA = 1;
} else {
adapter = ADAPTER_EGA;
}
} else {
adapter = ADAPTER_CGA;
}
video_vga.modes = mode_lists[adapter];
video_vga.card_name = card_name[adapter];
return mode_count[adapter];
}
__videocard video_vga =
{
.card_name = "VGA",
.probe = vga_probe,
.set_mode = vga_set_mode,
};
