1 /* -*- linux-c -*- ------------------------------------------------------- *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved
5 * Copyright 2009 Intel Corporation; author H. Peter Anvin
7 * This file is part of the Linux kernel, and is made available under
8 * the terms of the GNU General Public License version 2.
10 * ----------------------------------------------------------------------- */
13 * Common all-VGA modes
19 static struct mode_info vga_modes[] = {
20 { VIDEO_80x25, 80, 25, 0 },
21 { VIDEO_8POINT, 80, 50, 0 },
22 { VIDEO_80x43, 80, 43, 0 },
23 { VIDEO_80x28, 80, 28, 0 },
24 { VIDEO_80x30, 80, 30, 0 },
25 { VIDEO_80x34, 80, 34, 0 },
26 { VIDEO_80x60, 80, 60, 0 },
29 static struct mode_info ega_modes[] = {
30 { VIDEO_80x25, 80, 25, 0 },
31 { VIDEO_8POINT, 80, 43, 0 },
34 static struct mode_info cga_modes[] = {
35 { VIDEO_80x25, 80, 25, 0 },
38 static __videocard video_vga;
40 /* Set basic 80x25 mode */
41 static u8 vga_set_basic_mode(void)
43 struct biosregs ireg, oreg;
49 /* Query current mode */
51 intcall(0x10, &ireg, &oreg);
54 if (mode != 3 && mode != 7)
58 ireg.ax = mode; /* AH=0: set mode */
59 intcall(0x10, &ireg, NULL);
64 static void vga_set_8font(void)
66 /* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
74 intcall(0x10, &ireg, NULL);
76 /* Use alternate print screen */
79 intcall(0x10, &ireg, NULL);
81 /* Turn off cursor emulation */
84 intcall(0x10, &ireg, NULL);
86 /* Cursor is scan lines 6-7 */
89 intcall(0x10, &ireg, NULL);
92 static void vga_set_14font(void)
94 /* Set 9x14 font - 80x28 on VGA */
102 intcall(0x10, &ireg, NULL);
104 /* Turn off cursor emulation */
107 intcall(0x10, &ireg, NULL);
109 /* Cursor is scan lines 11-12 */
112 intcall(0x10, &ireg, NULL);
115 static void vga_set_80x43(void)
117 /* Set 80x43 mode on VGA (not EGA) */
118 struct biosregs ireg;
125 intcall(0x10, &ireg, NULL);
127 /* Reset video mode */
129 intcall(0x10, &ireg, NULL);
134 /* I/O address of the VGA CRTC */
137 return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
140 static void vga_set_480_scanlines(void)
142 u16 crtc; /* CRTC base address */
143 u8 csel; /* CRTC miscellaneous output register */
147 out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
148 out_idx(0x0b, crtc, 0x06); /* Vertical total */
149 out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
150 out_idx(0xea, crtc, 0x10); /* Vertical sync start */
151 out_idx(0xdf, crtc, 0x12); /* Vertical display end */
152 out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
153 out_idx(0x04, crtc, 0x16); /* Vertical blank end */
160 static void vga_set_vertical_end(int lines)
162 u16 crtc; /* CRTC base address */
163 u8 ovfw; /* CRTC overflow register */
168 ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40);
170 out_idx(ovfw, crtc, 0x07); /* Vertical overflow */
171 out_idx(end, crtc, 0x12); /* Vertical display end */
174 static void vga_set_80x30(void)
176 vga_set_480_scanlines();
177 vga_set_vertical_end(30*16);
180 static void vga_set_80x34(void)
182 vga_set_480_scanlines();
184 vga_set_vertical_end(34*14);
187 static void vga_set_80x60(void)
189 vga_set_480_scanlines();
191 vga_set_vertical_end(60*8);
194 static int vga_set_mode(struct mode_info *mode)
196 /* Set the basic mode */
197 vga_set_basic_mode();
199 /* Override a possibly broken BIOS */
203 switch (mode->mode) {
230 * Note: this probe includes basic information required by all
231 * systems. It should be executed first, by making sure
232 * video-vga.c is listed first in the Makefile.
234 static int vga_probe(void)
236 static const char *card_name[] = {
237 "CGA/MDA/HGC", "EGA", "VGA"
239 static struct mode_info *mode_lists[] = {
244 static int mode_count[] = {
245 sizeof(cga_modes)/sizeof(struct mode_info),
246 sizeof(ega_modes)/sizeof(struct mode_info),
247 sizeof(vga_modes)/sizeof(struct mode_info),
250 struct biosregs ireg, oreg;
255 ireg.bl = 0x10; /* Check EGA/VGA */
256 intcall(0x10, &ireg, &oreg);
259 boot_params.screen_info.orig_video_ega_bx = oreg.bx;
262 /* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
263 if (oreg.bl != 0x10) {
266 intcall(0x10, &ireg, &oreg);
268 if (oreg.al == 0x1a) {
269 adapter = ADAPTER_VGA;
271 boot_params.screen_info.orig_video_isVGA = 1;
274 adapter = ADAPTER_EGA;
277 adapter = ADAPTER_CGA;
280 video_vga.modes = mode_lists[adapter];
281 video_vga.card_name = card_name[adapter];
282 return mode_count[adapter];
285 static __videocard video_vga = {
288 .set_mode = vga_set_mode,