1 /* -*- linux-c -*- ------------------------------------------------------- *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved
6 * This file is part of the Linux kernel, and is made available under
7 * the terms of the GNU General Public License version 2.
9 * ----------------------------------------------------------------------- */
12 * arch/i386/boot/video-vga.c
14 * Common all-VGA modes
20 static struct mode_info vga_modes[] = {
21 { VIDEO_80x25, 80, 25 },
22 { VIDEO_8POINT, 80, 50 },
23 { VIDEO_80x43, 80, 43 },
24 { VIDEO_80x28, 80, 28 },
25 { VIDEO_80x30, 80, 30 },
26 { VIDEO_80x34, 80, 34 },
27 { VIDEO_80x60, 80, 60 },
30 static struct mode_info ega_modes[] = {
31 { VIDEO_80x25, 80, 25 },
32 { VIDEO_8POINT, 80, 43 },
35 static struct mode_info cga_modes[] = {
36 { VIDEO_80x25, 80, 25 },
39 __videocard video_vga;
41 /* Set basic 80x25 mode */
42 static u8 vga_set_basic_mode(void)
48 #ifdef CONFIG_VIDEO_400_HACK
49 if (adapter >= ADAPTER_VGA) {
51 : : "a" (0x1202), "b" (0x0030)
52 : "ecx", "edx", "esi", "edi");
59 : : "ebx", "ecx", "edx", "esi", "edi");
64 rows = rdfs8(0x484); /* rows minus one */
66 #ifndef CONFIG_VIDEO_400_HACK
67 if ((ax == 0x5003 || ax == 0x5007) &&
68 (rows == 0 || rows == 24))
72 if (mode != 3 && mode != 7)
78 : "ebx", "ecx", "edx", "esi", "edi");
83 static void vga_set_8font(void)
85 /* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
88 asm volatile(INT10 : : "a" (0x1112), "b" (0));
90 /* Use alternate print screen */
91 asm volatile(INT10 : : "a" (0x1200), "b" (0x20));
93 /* Turn off cursor emulation */
94 asm volatile(INT10 : : "a" (0x1201), "b" (0x34));
96 /* Cursor is scan lines 6-7 */
97 asm volatile(INT10 : : "a" (0x0100), "c" (0x0607));
100 static void vga_set_14font(void)
102 /* Set 9x14 font - 80x28 on VGA */
105 asm volatile(INT10 : : "a" (0x1111), "b" (0));
107 /* Turn off cursor emulation */
108 asm volatile(INT10 : : "a" (0x1201), "b" (0x34));
110 /* Cursor is scan lines 11-12 */
111 asm volatile(INT10 : : "a" (0x0100), "c" (0x0b0c));
114 static void vga_set_80x43(void)
116 /* Set 80x43 mode on VGA (not EGA) */
119 asm volatile(INT10 : : "a" (0x1201), "b" (0x30));
121 /* Reset video mode */
122 asm volatile(INT10 : : "a" (0x0003));
127 /* I/O address of the VGA CRTC */
130 return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
133 static void vga_set_480_scanlines(int end)
140 out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
141 out_idx(0x0b, crtc, 0x06); /* Vertical total */
142 out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
143 out_idx(0xea, crtc, 0x10); /* Vertical sync start */
144 out_idx(end, crtc, 0x12); /* Vertical display end */
145 out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
146 out_idx(0x04, crtc, 0x16); /* Vertical blank end */
153 static void vga_set_80x30(void)
155 vga_set_480_scanlines(0xdf);
158 static void vga_set_80x34(void)
161 vga_set_480_scanlines(0xdb);
164 static void vga_set_80x60(void)
167 vga_set_480_scanlines(0xdf);
170 static int vga_set_mode(struct mode_info *mode)
172 /* Set the basic mode */
173 vga_set_basic_mode();
175 /* Override a possibly broken BIOS */
179 switch (mode->mode) {
206 * Note: this probe includes basic information required by all
207 * systems. It should be executed first, by making sure
208 * video-vga.c is listed first in the Makefile.
210 static int vga_probe(void)
212 static const char *card_name[] = {
213 "CGA/MDA/HGC", "EGA", "VGA"
215 static struct mode_info *mode_lists[] = {
220 static int mode_count[] = {
221 sizeof(cga_modes)/sizeof(struct mode_info),
222 sizeof(ega_modes)/sizeof(struct mode_info),
223 sizeof(vga_modes)/sizeof(struct mode_info),
228 : "=b" (boot_params.screen_info.orig_video_ega_bx)
229 : "a" (0x1200), "b" (0x10) /* Check EGA/VGA */
230 : "ecx", "edx", "esi", "edi");
232 /* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
233 if ((u8)boot_params.screen_info.orig_video_ega_bx != 0x10) {
238 : "ebx", "ecx", "edx", "esi", "edi");
240 if (vga_flag == 0x1a) {
241 adapter = ADAPTER_VGA;
242 boot_params.screen_info.orig_video_isVGA = 1;
244 adapter = ADAPTER_EGA;
247 adapter = ADAPTER_CGA;
250 video_vga.modes = mode_lists[adapter];
251 video_vga.card_name = card_name[adapter];
252 return mode_count[adapter];
255 __videocard video_vga =
259 .set_mode = vga_set_mode,