1/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved
5 * Copyright 2009 Intel Corporation; author H. Peter Anvin
6 *
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.
9 *
10 * ----------------------------------------------------------------------- */
11
12/*
13 * Common all-VGA modes
14 */
15
16#include "boot.h"
17#include "video.h"
18
19static 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 },
27};
28
29static struct mode_info ega_modes[] = {
30 { VIDEO_80x25, 80, 25, 0 },
31 { VIDEO_8POINT, 80, 43, 0 },
32};
33
34static struct mode_info cga_modes[] = {
35 { VIDEO_80x25, 80, 25, 0 },
36};
37
38static __videocard video_vga;
39
40/* Set basic 80x25 mode */
41static u8 vga_set_basic_mode(void)
42{
43 struct biosregs ireg, oreg;
44 u8 mode;
45
46 initregs(&ireg);
47
48 /* Query current mode */
49 ireg.ax = 0x0f00;
50 intcall(0x10, &ireg, &oreg);
51 mode = oreg.al;
52
53 if (mode != 3 && mode != 7)
54 mode = 3;
55
56 /* Set the mode */
57 ireg.ax = mode; /* AH=0: set mode */
58 intcall(0x10, &ireg, NULL);
59 do_restore = 1;
60 return mode;
61}
62
63static void vga_set_8font(void)
64{
65 /* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
66 struct biosregs ireg;
67
68 initregs(&ireg);
69
70 /* Set 8x8 font */
71 ireg.ax = 0x1112;
72 /* ireg.bl = 0; */
73 intcall(0x10, &ireg, NULL);
74
75 /* Use alternate print screen */
76 ireg.ax = 0x1200;
77 ireg.bl = 0x20;
78 intcall(0x10, &ireg, NULL);
79
80 /* Turn off cursor emulation */
81 ireg.ax = 0x1201;
82 ireg.bl = 0x34;
83 intcall(0x10, &ireg, NULL);
84
85 /* Cursor is scan lines 6-7 */
86 ireg.ax = 0x0100;
87 ireg.cx = 0x0607;
88 intcall(0x10, &ireg, NULL);
89}
90
91static void vga_set_14font(void)
92{
93 /* Set 9x14 font - 80x28 on VGA */
94 struct biosregs ireg;
95
96 initregs(&ireg);
97
98 /* Set 9x14 font */
99 ireg.ax = 0x1111;
100 /* ireg.bl = 0; */
101 intcall(0x10, &ireg, NULL);
102
103 /* Turn off cursor emulation */
104 ireg.ax = 0x1201;
105 ireg.bl = 0x34;
106 intcall(0x10, &ireg, NULL);
107
108 /* Cursor is scan lines 11-12 */
109 ireg.ax = 0x0100;
110 ireg.cx = 0x0b0c;
111 intcall(0x10, &ireg, NULL);
112}
113
114static void vga_set_80x43(void)
115{
116 /* Set 80x43 mode on VGA (not EGA) */
117 struct biosregs ireg;
118
119 initregs(&ireg);
120
121 /* Set 350 scans */
122 ireg.ax = 0x1201;
123 ireg.bl = 0x30;
124 intcall(0x10, &ireg, NULL);
125
126 /* Reset video mode */
127 ireg.ax = 0x0003;
128 intcall(0x10, &ireg, NULL);
129
130 vga_set_8font();
131}
132
133/* I/O address of the VGA CRTC */
134u16 vga_crtc(void)
135{
136 return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
137}
138
139static void vga_set_480_scanlines(void)
140{
141 u16 crtc; /* CRTC base address */
142 u8 csel; /* CRTC miscellaneous output register */
143
144 crtc = vga_crtc();
145
146 out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
147 out_idx(0x0b, crtc, 0x06); /* Vertical total */
148 out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
149 out_idx(0xea, crtc, 0x10); /* Vertical sync start */
150 out_idx(0xdf, crtc, 0x12); /* Vertical display end */
151 out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
152 out_idx(0x04, crtc, 0x16); /* Vertical blank end */
153 csel = inb(0x3cc);
154 csel &= 0x0d;
155 csel |= 0xe2;
156 outb(csel, 0x3c2);
157}
158
159static void vga_set_vertical_end(int lines)
160{
161 u16 crtc; /* CRTC base address */
162 u8 ovfw; /* CRTC overflow register */
163 int end = lines-1;
164
165 crtc = vga_crtc();
166
167 ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40);
168
169 out_idx(ovfw, crtc, 0x07); /* Vertical overflow */
170 out_idx(end, crtc, 0x12); /* Vertical display end */
171}
172
173static void vga_set_80x30(void)
174{
175 vga_set_480_scanlines();
176 vga_set_vertical_end(30*16);
177}
178
179static void vga_set_80x34(void)
180{
181 vga_set_480_scanlines();
182 vga_set_14font();
183 vga_set_vertical_end(34*14);
184}
185
186static void vga_set_80x60(void)
187{
188 vga_set_480_scanlines();
189 vga_set_8font();
190 vga_set_vertical_end(60*8);
191}
192
193static int vga_set_mode(struct mode_info *mode)
194{
195 /* Set the basic mode */
196 vga_set_basic_mode();
197
198 /* Override a possibly broken BIOS */
199 force_x = mode->x;
200 force_y = mode->y;
201
202 switch (mode->mode) {
203 case VIDEO_80x25:
204 break;
205 case VIDEO_8POINT:
206 vga_set_8font();
207 break;
208 case VIDEO_80x43:
209 vga_set_80x43();
210 break;
211 case VIDEO_80x28:
212 vga_set_14font();
213 break;
214 case VIDEO_80x30:
215 vga_set_80x30();
216 break;
217 case VIDEO_80x34:
218 vga_set_80x34();
219 break;
220 case VIDEO_80x60:
221 vga_set_80x60();
222 break;
223 }
224
225 return 0;
226}
227
228/*
229 * Note: this probe includes basic information required by all
230 * systems. It should be executed first, by making sure
231 * video-vga.c is listed first in the Makefile.
232 */
233static int vga_probe(void)
234{
235 static const char *card_name[] = {
236 "CGA/MDA/HGC", "EGA", "VGA"
237 };
238 static struct mode_info *mode_lists[] = {
239 cga_modes,
240 ega_modes,
241 vga_modes,
242 };
243 static int mode_count[] = {
244 ARRAY_SIZE(cga_modes),
245 ARRAY_SIZE(ega_modes),
246 ARRAY_SIZE(vga_modes),
247 };
248
249 struct biosregs ireg, oreg;
250
251 initregs(&ireg);
252
253 ireg.ax = 0x1200;
254 ireg.bl = 0x10; /* Check EGA/VGA */
255 intcall(0x10, &ireg, &oreg);
256
257#ifndef _WAKEUP
258 boot_params.screen_info.orig_video_ega_bx = oreg.bx;
259#endif
260
261 /* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
262 if (oreg.bl != 0x10) {
263 /* EGA/VGA */
264 ireg.ax = 0x1a00;
265 intcall(0x10, &ireg, &oreg);
266
267 if (oreg.al == 0x1a) {
268 adapter = ADAPTER_VGA;
269#ifndef _WAKEUP
270 boot_params.screen_info.orig_video_isVGA = 1;
271#endif
272 } else {
273 adapter = ADAPTER_EGA;
274 }
275 } else {
276 adapter = ADAPTER_CGA;
277 }
278
279 video_vga.modes = mode_lists[adapter];
280 video_vga.card_name = card_name[adapter];
281 return mode_count[adapter];
282}
283
284static __videocard video_vga = {
285 .card_name = "VGA",
286 .probe = vga_probe,
287 .set_mode = vga_set_mode,
288};
289