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// SPDX-License-Identifier: GPL-2.0-only
/* -*- linux-c -*- ------------------------------------------------------- *
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright 2007 rPath, Inc. - All Rights Reserved
* Copyright 2009 Intel Corporation; author H. Peter Anvin
*
* ----------------------------------------------------------------------- */
/*
* 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 },
};
static __videocard video_vga;
/* Set basic 80x25 mode */
static u8 vga_set_basic_mode(void)
{
struct biosregs ireg, oreg;
u8 mode;
initregs(&ireg);
/* Query current mode */
ireg.ax = 0x0f00;
intcall(0x10, &ireg, &oreg);
mode = oreg.al;
if (mode != 3 && mode != 7)
mode = 3;
/* Set the mode */
ireg.ax = mode; /* AH=0: set mode */
intcall(0x10, &ireg, NULL);
do_restore = 1;
return mode;
}
static void vga_set_8font(void)
{
/* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
struct biosregs ireg;
initregs(&ireg);
/* Set 8x8 font */
ireg.ax = 0x1112;
/* ireg.bl = 0; */
intcall(0x10, &ireg, NULL);
/* Use alternate print screen */
ireg.ax = 0x1200;
ireg.bl = 0x20;
intcall(0x10, &ireg, NULL);
/* Turn off cursor emulation */
ireg.ax = 0x1201;
ireg.bl = 0x34;
intcall(0x10, &ireg, NULL);
/* Cursor is scan lines 6-7 */
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 */
ireg.ax = 0x1111;
/* ireg.bl = 0; */
intcall(0x10, &ireg, NULL);
/* Turn off cursor emulation */
ireg.ax = 0x1201;
ireg.bl = 0x34;
intcall(0x10, &ireg, NULL);
/* Cursor is scan lines 11-12 */
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 */
ireg.ax = 0x1201;
ireg.bl = 0x30;
intcall(0x10, &ireg, NULL);
/* Reset video mode */
ireg.ax = 0x0003;
intcall(0x10, &ireg, NULL);
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(void)
{
u16 crtc; /* CRTC base address */
u8 csel; /* CRTC miscellaneous output register */
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(0xdf, 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, 0x3c2);
}
static void vga_set_vertical_end(int lines)
{
u16 crtc; /* CRTC base address */
u8 ovfw; /* CRTC overflow register */
int end = lines-1;
crtc = vga_crtc();
ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40);
out_idx(ovfw, crtc, 0x07); /* Vertical overflow */
out_idx(end, crtc, 0x12); /* Vertical display end */
}
static void vga_set_80x30(void)
{
vga_set_480_scanlines();
vga_set_vertical_end(30*16);
}
static void vga_set_80x34(void)
{
vga_set_480_scanlines();
vga_set_14font();
vga_set_vertical_end(34*14);
}
static void vga_set_80x60(void)
{
vga_set_480_scanlines();
vga_set_8font();
vga_set_vertical_end(60*8);
}
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[] = {
ARRAY_SIZE(cga_modes),
ARRAY_SIZE(ega_modes),
ARRAY_SIZE(vga_modes),
};
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 = oreg.bx;
#endif
/* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
if (oreg.bl != 0x10) {
/* EGA/VGA */
ireg.ax = 0x1a00;
intcall(0x10, &ireg, &oreg);
if (oreg.al == 0x1a) {
adapter = ADAPTER_VGA;
#ifndef _WAKEUP
boot_params.screen_info.orig_video_isVGA = 1;
#endif
} 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];
}
static __videocard video_vga = {
.card_name = "VGA",
.probe = vga_probe,
.set_mode = vga_set_mode,
};
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