![H. Peter Anvin](/assets/img/avatar_default.png)
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>
307 lines
6 KiB
C
307 lines
6 KiB
C
/* -*- linux-c -*- ------------------------------------------------------- *
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright 2007 rPath, Inc. - All Rights Reserved
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* Copyright 2009 Intel Corporation; author H. Peter Anvin
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*
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* This file is part of the Linux kernel, and is made available under
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* the terms of the GNU General Public License version 2.
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*
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* ----------------------------------------------------------------------- */
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/*
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* Common all-VGA modes
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*/
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#include "boot.h"
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#include "video.h"
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static struct mode_info vga_modes[] = {
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{ VIDEO_80x25, 80, 25, 0 },
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{ VIDEO_8POINT, 80, 50, 0 },
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{ VIDEO_80x43, 80, 43, 0 },
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{ VIDEO_80x28, 80, 28, 0 },
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{ VIDEO_80x30, 80, 30, 0 },
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{ VIDEO_80x34, 80, 34, 0 },
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{ VIDEO_80x60, 80, 60, 0 },
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};
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static struct mode_info ega_modes[] = {
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{ VIDEO_80x25, 80, 25, 0 },
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{ VIDEO_8POINT, 80, 43, 0 },
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};
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static struct mode_info cga_modes[] = {
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{ VIDEO_80x25, 80, 25, 0 },
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};
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static __videocard video_vga;
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/* Set basic 80x25 mode */
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static u8 vga_set_basic_mode(void)
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{
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struct biosregs ireg, oreg;
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u16 ax;
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u8 rows;
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u8 mode;
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initregs(&ireg);
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#ifdef CONFIG_VIDEO_400_HACK
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if (adapter >= ADAPTER_VGA) {
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ireg.ax = 0x1202;
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ireg.bx = 0x0030;
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intcall(0x10, &ireg, NULL);
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}
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#endif
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ax = 0x0f00;
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intcall(0x10, &ireg, &oreg);
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mode = oreg.al;
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set_fs(0);
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rows = rdfs8(0x484); /* rows minus one */
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#ifndef CONFIG_VIDEO_400_HACK
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if ((oreg.ax == 0x5003 || oreg.ax == 0x5007) &&
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(rows == 0 || rows == 24))
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return mode;
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#endif
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if (mode != 3 && mode != 7)
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mode = 3;
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/* Set the mode */
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ireg.ax = mode; /* AH=0: set mode */
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intcall(0x10, &ireg, NULL);
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do_restore = 1;
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return mode;
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}
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static void vga_set_8font(void)
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{
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/* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
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struct biosregs ireg;
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initregs(&ireg);
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/* Set 8x8 font */
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ireg.ax = 0x1112;
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/* ireg.bl = 0; */
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intcall(0x10, &ireg, NULL);
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/* Use alternate print screen */
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ireg.ax = 0x1200;
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ireg.bl = 0x20;
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intcall(0x10, &ireg, NULL);
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/* Turn off cursor emulation */
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ireg.ax = 0x1201;
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ireg.bl = 0x34;
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intcall(0x10, &ireg, NULL);
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/* Cursor is scan lines 6-7 */
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ireg.ax = 0x0100;
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ireg.cx = 0x0607;
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intcall(0x10, &ireg, NULL);
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}
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static void vga_set_14font(void)
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{
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/* Set 9x14 font - 80x28 on VGA */
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struct biosregs ireg;
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initregs(&ireg);
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/* Set 9x14 font */
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ireg.ax = 0x1111;
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/* ireg.bl = 0; */
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intcall(0x10, &ireg, NULL);
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/* Turn off cursor emulation */
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ireg.ax = 0x1201;
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ireg.bl = 0x34;
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intcall(0x10, &ireg, NULL);
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/* Cursor is scan lines 11-12 */
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ireg.ax = 0x0100;
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ireg.cx = 0x0b0c;
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intcall(0x10, &ireg, NULL);
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}
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static void vga_set_80x43(void)
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{
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/* Set 80x43 mode on VGA (not EGA) */
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struct biosregs ireg;
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initregs(&ireg);
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/* Set 350 scans */
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ireg.ax = 0x1201;
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ireg.bl = 0x30;
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intcall(0x10, &ireg, NULL);
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/* Reset video mode */
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ireg.ax = 0x0003;
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intcall(0x10, &ireg, NULL);
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vga_set_8font();
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}
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/* I/O address of the VGA CRTC */
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u16 vga_crtc(void)
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{
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return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
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}
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static void vga_set_480_scanlines(void)
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{
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u16 crtc; /* CRTC base address */
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u8 csel; /* CRTC miscellaneous output register */
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crtc = vga_crtc();
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out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
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out_idx(0x0b, crtc, 0x06); /* Vertical total */
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out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
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out_idx(0xea, crtc, 0x10); /* Vertical sync start */
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out_idx(0xdf, crtc, 0x12); /* Vertical display end */
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out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
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out_idx(0x04, crtc, 0x16); /* Vertical blank end */
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csel = inb(0x3cc);
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csel &= 0x0d;
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csel |= 0xe2;
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outb(csel, 0x3c2);
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}
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static void vga_set_vertical_end(int lines)
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{
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u16 crtc; /* CRTC base address */
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u8 ovfw; /* CRTC overflow register */
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int end = lines-1;
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crtc = vga_crtc();
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ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40);
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out_idx(ovfw, crtc, 0x07); /* Vertical overflow */
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out_idx(end, crtc, 0x12); /* Vertical display end */
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}
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static void vga_set_80x30(void)
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{
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vga_set_480_scanlines();
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vga_set_vertical_end(30*16);
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}
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static void vga_set_80x34(void)
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{
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vga_set_480_scanlines();
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vga_set_14font();
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vga_set_vertical_end(34*14);
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}
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static void vga_set_80x60(void)
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{
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vga_set_480_scanlines();
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vga_set_8font();
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vga_set_vertical_end(60*8);
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}
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static int vga_set_mode(struct mode_info *mode)
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{
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/* Set the basic mode */
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vga_set_basic_mode();
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/* Override a possibly broken BIOS */
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force_x = mode->x;
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force_y = mode->y;
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switch (mode->mode) {
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case VIDEO_80x25:
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break;
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case VIDEO_8POINT:
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vga_set_8font();
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break;
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case VIDEO_80x43:
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vga_set_80x43();
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break;
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case VIDEO_80x28:
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vga_set_14font();
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break;
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case VIDEO_80x30:
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vga_set_80x30();
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break;
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case VIDEO_80x34:
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vga_set_80x34();
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break;
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case VIDEO_80x60:
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vga_set_80x60();
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break;
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}
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return 0;
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}
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/*
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* Note: this probe includes basic information required by all
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* systems. It should be executed first, by making sure
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* video-vga.c is listed first in the Makefile.
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*/
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static int vga_probe(void)
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{
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static const char *card_name[] = {
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"CGA/MDA/HGC", "EGA", "VGA"
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};
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static struct mode_info *mode_lists[] = {
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cga_modes,
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ega_modes,
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vga_modes,
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};
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static int mode_count[] = {
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sizeof(cga_modes)/sizeof(struct mode_info),
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sizeof(ega_modes)/sizeof(struct mode_info),
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sizeof(vga_modes)/sizeof(struct mode_info),
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};
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struct biosregs ireg, oreg;
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initregs(&ireg);
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ireg.ax = 0x1200;
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ireg.bl = 0x10; /* Check EGA/VGA */
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intcall(0x10, &ireg, &oreg);
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#ifndef _WAKEUP
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boot_params.screen_info.orig_video_ega_bx = oreg.bx;
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#endif
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/* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
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if (oreg.bl != 0x10) {
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/* EGA/VGA */
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ireg.ax = 0x1a00;
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intcall(0x10, &ireg, &oreg);
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if (oreg.al == 0x1a) {
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adapter = ADAPTER_VGA;
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#ifndef _WAKEUP
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boot_params.screen_info.orig_video_isVGA = 1;
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#endif
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} else {
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adapter = ADAPTER_EGA;
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}
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} else {
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adapter = ADAPTER_CGA;
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}
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video_vga.modes = mode_lists[adapter];
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video_vga.card_name = card_name[adapter];
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return mode_count[adapter];
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}
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static __videocard video_vga = {
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.card_name = "VGA",
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.probe = vga_probe,
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.set_mode = vga_set_mode,
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};
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