1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* -*- linux-c -*- ------------------------------------------------------- * |
3 | * |
4 | * Copyright (C) 1991, 1992 Linus Torvalds |
5 | * Copyright 2007 rPath, Inc. - All Rights Reserved |
6 | * Copyright 2009 Intel Corporation; author H. Peter Anvin |
7 | * |
8 | * ----------------------------------------------------------------------- */ |
9 | |
10 | /* |
11 | * Common all-VGA modes |
12 | */ |
13 | |
14 | #include "boot.h" |
15 | #include "video.h" |
16 | |
17 | static struct mode_info vga_modes[] = { |
18 | { VIDEO_80x25, 80, 25, 0 }, |
19 | { VIDEO_8POINT, 80, 50, 0 }, |
20 | { VIDEO_80x43, 80, 43, 0 }, |
21 | { VIDEO_80x28, 80, 28, 0 }, |
22 | { VIDEO_80x30, 80, 30, 0 }, |
23 | { VIDEO_80x34, 80, 34, 0 }, |
24 | { VIDEO_80x60, 80, 60, 0 }, |
25 | }; |
26 | |
27 | static struct mode_info ega_modes[] = { |
28 | { VIDEO_80x25, 80, 25, 0 }, |
29 | { VIDEO_8POINT, 80, 43, 0 }, |
30 | }; |
31 | |
32 | static struct mode_info cga_modes[] = { |
33 | { VIDEO_80x25, 80, 25, 0 }, |
34 | }; |
35 | |
36 | static __videocard video_vga; |
37 | |
38 | /* Set basic 80x25 mode */ |
39 | static u8 vga_set_basic_mode(void) |
40 | { |
41 | struct biosregs ireg, oreg; |
42 | u8 mode; |
43 | |
44 | initregs(regs: &ireg); |
45 | |
46 | /* Query current mode */ |
47 | ireg.ax = 0x0f00; |
48 | intcall(int_no: 0x10, ireg: &ireg, oreg: &oreg); |
49 | mode = oreg.al; |
50 | |
51 | if (mode != 3 && mode != 7) |
52 | mode = 3; |
53 | |
54 | /* Set the mode */ |
55 | ireg.ax = mode; /* AH=0: set mode */ |
56 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
57 | do_restore = 1; |
58 | return mode; |
59 | } |
60 | |
61 | static void vga_set_8font(void) |
62 | { |
63 | /* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */ |
64 | struct biosregs ireg; |
65 | |
66 | initregs(regs: &ireg); |
67 | |
68 | /* Set 8x8 font */ |
69 | ireg.ax = 0x1112; |
70 | /* ireg.bl = 0; */ |
71 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
72 | |
73 | /* Use alternate print screen */ |
74 | ireg.ax = 0x1200; |
75 | ireg.bl = 0x20; |
76 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
77 | |
78 | /* Turn off cursor emulation */ |
79 | ireg.ax = 0x1201; |
80 | ireg.bl = 0x34; |
81 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
82 | |
83 | /* Cursor is scan lines 6-7 */ |
84 | ireg.ax = 0x0100; |
85 | ireg.cx = 0x0607; |
86 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
87 | } |
88 | |
89 | static void vga_set_14font(void) |
90 | { |
91 | /* Set 9x14 font - 80x28 on VGA */ |
92 | struct biosregs ireg; |
93 | |
94 | initregs(regs: &ireg); |
95 | |
96 | /* Set 9x14 font */ |
97 | ireg.ax = 0x1111; |
98 | /* ireg.bl = 0; */ |
99 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
100 | |
101 | /* Turn off cursor emulation */ |
102 | ireg.ax = 0x1201; |
103 | ireg.bl = 0x34; |
104 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
105 | |
106 | /* Cursor is scan lines 11-12 */ |
107 | ireg.ax = 0x0100; |
108 | ireg.cx = 0x0b0c; |
109 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
110 | } |
111 | |
112 | static void vga_set_80x43(void) |
113 | { |
114 | /* Set 80x43 mode on VGA (not EGA) */ |
115 | struct biosregs ireg; |
116 | |
117 | initregs(regs: &ireg); |
118 | |
119 | /* Set 350 scans */ |
120 | ireg.ax = 0x1201; |
121 | ireg.bl = 0x30; |
122 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
123 | |
124 | /* Reset video mode */ |
125 | ireg.ax = 0x0003; |
126 | intcall(int_no: 0x10, ireg: &ireg, NULL); |
127 | |
128 | vga_set_8font(); |
129 | } |
130 | |
131 | /* I/O address of the VGA CRTC */ |
132 | u16 vga_crtc(void) |
133 | { |
134 | return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4; |
135 | } |
136 | |
137 | static void vga_set_480_scanlines(void) |
138 | { |
139 | u16 crtc; /* CRTC base address */ |
140 | u8 csel; /* CRTC miscellaneous output register */ |
141 | |
142 | crtc = vga_crtc(); |
143 | |
144 | out_idx(v: 0x0c, port: crtc, index: 0x11); /* Vertical sync end, unlock CR0-7 */ |
145 | out_idx(v: 0x0b, port: crtc, index: 0x06); /* Vertical total */ |
146 | out_idx(v: 0x3e, port: crtc, index: 0x07); /* Vertical overflow */ |
147 | out_idx(v: 0xea, port: crtc, index: 0x10); /* Vertical sync start */ |
148 | out_idx(v: 0xdf, port: crtc, index: 0x12); /* Vertical display end */ |
149 | out_idx(v: 0xe7, port: crtc, index: 0x15); /* Vertical blank start */ |
150 | out_idx(v: 0x04, port: crtc, index: 0x16); /* Vertical blank end */ |
151 | csel = inb(0x3cc); |
152 | csel &= 0x0d; |
153 | csel |= 0xe2; |
154 | outb(csel, 0x3c2); |
155 | } |
156 | |
157 | static void vga_set_vertical_end(int lines) |
158 | { |
159 | u16 crtc; /* CRTC base address */ |
160 | u8 ovfw; /* CRTC overflow register */ |
161 | int end = lines-1; |
162 | |
163 | crtc = vga_crtc(); |
164 | |
165 | ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40); |
166 | |
167 | out_idx(v: ovfw, port: crtc, index: 0x07); /* Vertical overflow */ |
168 | out_idx(v: end, port: crtc, index: 0x12); /* Vertical display end */ |
169 | } |
170 | |
171 | static void vga_set_80x30(void) |
172 | { |
173 | vga_set_480_scanlines(); |
174 | vga_set_vertical_end(lines: 30*16); |
175 | } |
176 | |
177 | static void vga_set_80x34(void) |
178 | { |
179 | vga_set_480_scanlines(); |
180 | vga_set_14font(); |
181 | vga_set_vertical_end(lines: 34*14); |
182 | } |
183 | |
184 | static void vga_set_80x60(void) |
185 | { |
186 | vga_set_480_scanlines(); |
187 | vga_set_8font(); |
188 | vga_set_vertical_end(lines: 60*8); |
189 | } |
190 | |
191 | static int vga_set_mode(struct mode_info *mode) |
192 | { |
193 | /* Set the basic mode */ |
194 | vga_set_basic_mode(); |
195 | |
196 | /* Override a possibly broken BIOS */ |
197 | force_x = mode->x; |
198 | force_y = mode->y; |
199 | |
200 | switch (mode->mode) { |
201 | case VIDEO_80x25: |
202 | break; |
203 | case VIDEO_8POINT: |
204 | vga_set_8font(); |
205 | break; |
206 | case VIDEO_80x43: |
207 | vga_set_80x43(); |
208 | break; |
209 | case VIDEO_80x28: |
210 | vga_set_14font(); |
211 | break; |
212 | case VIDEO_80x30: |
213 | vga_set_80x30(); |
214 | break; |
215 | case VIDEO_80x34: |
216 | vga_set_80x34(); |
217 | break; |
218 | case VIDEO_80x60: |
219 | vga_set_80x60(); |
220 | break; |
221 | } |
222 | |
223 | return 0; |
224 | } |
225 | |
226 | /* |
227 | * Note: this probe includes basic information required by all |
228 | * systems. It should be executed first, by making sure |
229 | * video-vga.c is listed first in the Makefile. |
230 | */ |
231 | static int vga_probe(void) |
232 | { |
233 | static const char *card_name[] = { |
234 | "CGA/MDA/HGC" , "EGA" , "VGA" |
235 | }; |
236 | static struct mode_info *mode_lists[] = { |
237 | cga_modes, |
238 | ega_modes, |
239 | vga_modes, |
240 | }; |
241 | static int mode_count[] = { |
242 | ARRAY_SIZE(cga_modes), |
243 | ARRAY_SIZE(ega_modes), |
244 | ARRAY_SIZE(vga_modes), |
245 | }; |
246 | |
247 | struct biosregs ireg, oreg; |
248 | |
249 | initregs(regs: &ireg); |
250 | |
251 | ireg.ax = 0x1200; |
252 | ireg.bl = 0x10; /* Check EGA/VGA */ |
253 | intcall(int_no: 0x10, ireg: &ireg, oreg: &oreg); |
254 | |
255 | #ifndef _WAKEUP |
256 | boot_params.screen_info.orig_video_ega_bx = oreg.bx; |
257 | #endif |
258 | |
259 | /* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */ |
260 | if (oreg.bl != 0x10) { |
261 | /* EGA/VGA */ |
262 | ireg.ax = 0x1a00; |
263 | intcall(int_no: 0x10, ireg: &ireg, oreg: &oreg); |
264 | |
265 | if (oreg.al == 0x1a) { |
266 | adapter = ADAPTER_VGA; |
267 | #ifndef _WAKEUP |
268 | boot_params.screen_info.orig_video_isVGA = 1; |
269 | #endif |
270 | } else { |
271 | adapter = ADAPTER_EGA; |
272 | } |
273 | } else { |
274 | adapter = ADAPTER_CGA; |
275 | } |
276 | |
277 | video_vga.modes = mode_lists[adapter]; |
278 | video_vga.card_name = card_name[adapter]; |
279 | return mode_count[adapter]; |
280 | } |
281 | |
282 | static __videocard video_vga = { |
283 | .card_name = "VGA" , |
284 | .probe = vga_probe, |
285 | .set_mode = vga_set_mode, |
286 | }; |
287 | |