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 * Select video mode
14 */
15
16 #include "boot.h"
17 #include "video.h"
18 #include "vesa.h"
19
store_cursor_position(void)20 static void store_cursor_position(void)
21 {
22 struct biosregs ireg, oreg;
23
24 initregs(&ireg);
25 ireg.ah = 0x03;
26 intcall(0x10, &ireg, &oreg);
27
28 boot_params.screen_info.orig_x = oreg.dl;
29 boot_params.screen_info.orig_y = oreg.dh;
30
31 if (oreg.ch & 0x20)
32 boot_params.screen_info.flags |= VIDEO_FLAGS_NOCURSOR;
33
34 if ((oreg.ch & 0x1f) > (oreg.cl & 0x1f))
35 boot_params.screen_info.flags |= VIDEO_FLAGS_NOCURSOR;
36 }
37
store_video_mode(void)38 static void store_video_mode(void)
39 {
40 struct biosregs ireg, oreg;
41
42 /* N.B.: the saving of the video page here is a bit silly,
43 since we pretty much assume page 0 everywhere. */
44 initregs(&ireg);
45 ireg.ah = 0x0f;
46 intcall(0x10, &ireg, &oreg);
47
48 /* Not all BIOSes are clean with respect to the top bit */
49 boot_params.screen_info.orig_video_mode = oreg.al & 0x7f;
50 boot_params.screen_info.orig_video_page = oreg.bh;
51 }
52
53 /*
54 * Store the video mode parameters for later usage by the kernel.
55 * This is done by asking the BIOS except for the rows/columns
56 * parameters in the default 80x25 mode -- these are set directly,
57 * because some very obscure BIOSes supply insane values.
58 */
store_mode_params(void)59 static void store_mode_params(void)
60 {
61 u16 font_size;
62 int x, y;
63
64 /* For graphics mode, it is up to the mode-setting driver
65 (currently only video-vesa.c) to store the parameters */
66 if (graphic_mode)
67 return;
68
69 store_cursor_position();
70 store_video_mode();
71
72 if (boot_params.screen_info.orig_video_mode == 0x07) {
73 /* MDA, HGC, or VGA in monochrome mode */
74 video_segment = 0xb000;
75 } else {
76 /* CGA, EGA, VGA and so forth */
77 video_segment = 0xb800;
78 }
79
80 set_fs(0);
81 font_size = rdfs16(0x485); /* Font size, BIOS area */
82 boot_params.screen_info.orig_video_points = font_size;
83
84 x = rdfs16(0x44a);
85 y = (adapter == ADAPTER_CGA) ? 25 : rdfs8(0x484)+1;
86
87 if (force_x)
88 x = force_x;
89 if (force_y)
90 y = force_y;
91
92 boot_params.screen_info.orig_video_cols = x;
93 boot_params.screen_info.orig_video_lines = y;
94 }
95
get_entry(void)96 static unsigned int get_entry(void)
97 {
98 char entry_buf[4];
99 int i, len = 0;
100 int key;
101 unsigned int v;
102
103 do {
104 key = getchar();
105
106 if (key == '\b') {
107 if (len > 0) {
108 puts("\b \b");
109 len--;
110 }
111 } else if ((key >= '0' && key <= '9') ||
112 (key >= 'A' && key <= 'Z') ||
113 (key >= 'a' && key <= 'z')) {
114 if (len < sizeof entry_buf) {
115 entry_buf[len++] = key;
116 putchar(key);
117 }
118 }
119 } while (key != '\r');
120 putchar('\n');
121
122 if (len == 0)
123 return VIDEO_CURRENT_MODE; /* Default */
124
125 v = 0;
126 for (i = 0; i < len; i++) {
127 v <<= 4;
128 key = entry_buf[i] | 0x20;
129 v += (key > '9') ? key-'a'+10 : key-'0';
130 }
131
132 return v;
133 }
134
display_menu(void)135 static void display_menu(void)
136 {
137 struct card_info *card;
138 struct mode_info *mi;
139 char ch;
140 int i;
141 int nmodes;
142 int modes_per_line;
143 int col;
144
145 nmodes = 0;
146 for (card = video_cards; card < video_cards_end; card++)
147 nmodes += card->nmodes;
148
149 modes_per_line = 1;
150 if (nmodes >= 20)
151 modes_per_line = 3;
152
153 for (col = 0; col < modes_per_line; col++)
154 puts("Mode: Resolution: Type: ");
155 putchar('\n');
156
157 col = 0;
158 ch = '0';
159 for (card = video_cards; card < video_cards_end; card++) {
160 mi = card->modes;
161 for (i = 0; i < card->nmodes; i++, mi++) {
162 char resbuf[32];
163 int visible = mi->x && mi->y;
164 u16 mode_id = mi->mode ? mi->mode :
165 (mi->y << 8)+mi->x;
166
167 if (!visible)
168 continue; /* Hidden mode */
169
170 if (mi->depth)
171 sprintf(resbuf, "%dx%d", mi->y, mi->depth);
172 else
173 sprintf(resbuf, "%d", mi->y);
174
175 printf("%c %03X %4dx%-7s %-6s",
176 ch, mode_id, mi->x, resbuf, card->card_name);
177 col++;
178 if (col >= modes_per_line) {
179 putchar('\n');
180 col = 0;
181 }
182
183 if (ch == '9')
184 ch = 'a';
185 else if (ch == 'z' || ch == ' ')
186 ch = ' '; /* Out of keys... */
187 else
188 ch++;
189 }
190 }
191 if (col)
192 putchar('\n');
193 }
194
195 #define H(x) ((x)-'a'+10)
196 #define SCAN ((H('s')<<12)+(H('c')<<8)+(H('a')<<4)+H('n'))
197
mode_menu(void)198 static unsigned int mode_menu(void)
199 {
200 int key;
201 unsigned int sel;
202
203 puts("Press <ENTER> to see video modes available, "
204 "<SPACE> to continue, or wait 30 sec\n");
205
206 kbd_flush();
207 while (1) {
208 key = getchar_timeout();
209 if (key == ' ' || key == 0)
210 return VIDEO_CURRENT_MODE; /* Default */
211 if (key == '\r')
212 break;
213 putchar('\a'); /* Beep! */
214 }
215
216
217 for (;;) {
218 display_menu();
219
220 puts("Enter a video mode or \"scan\" to scan for "
221 "additional modes: ");
222 sel = get_entry();
223 if (sel != SCAN)
224 return sel;
225
226 probe_cards(1);
227 }
228 }
229
230 /* Save screen content to the heap */
231 static struct saved_screen {
232 int x, y;
233 int curx, cury;
234 u16 *data;
235 } saved;
236
save_screen(void)237 static void save_screen(void)
238 {
239 /* Should be called after store_mode_params() */
240 saved.x = boot_params.screen_info.orig_video_cols;
241 saved.y = boot_params.screen_info.orig_video_lines;
242 saved.curx = boot_params.screen_info.orig_x;
243 saved.cury = boot_params.screen_info.orig_y;
244
245 if (!heap_free(saved.x*saved.y*sizeof(u16)+512))
246 return; /* Not enough heap to save the screen */
247
248 saved.data = GET_HEAP(u16, saved.x*saved.y);
249
250 set_fs(video_segment);
251 copy_from_fs(saved.data, 0, saved.x*saved.y*sizeof(u16));
252 }
253
restore_screen(void)254 static void restore_screen(void)
255 {
256 /* Should be called after store_mode_params() */
257 int xs = boot_params.screen_info.orig_video_cols;
258 int ys = boot_params.screen_info.orig_video_lines;
259 int y;
260 addr_t dst = 0;
261 u16 *src = saved.data;
262 struct biosregs ireg;
263
264 if (graphic_mode)
265 return; /* Can't restore onto a graphic mode */
266
267 if (!src)
268 return; /* No saved screen contents */
269
270 /* Restore screen contents */
271
272 set_fs(video_segment);
273 for (y = 0; y < ys; y++) {
274 int npad;
275
276 if (y < saved.y) {
277 int copy = (xs < saved.x) ? xs : saved.x;
278 copy_to_fs(dst, src, copy*sizeof(u16));
279 dst += copy*sizeof(u16);
280 src += saved.x;
281 npad = (xs < saved.x) ? 0 : xs-saved.x;
282 } else {
283 npad = xs;
284 }
285
286 /* Writes "npad" blank characters to
287 video_segment:dst and advances dst */
288 asm volatile("pushw %%es ; "
289 "movw %2,%%es ; "
290 "shrw %%cx ; "
291 "jnc 1f ; "
292 "stosw \n\t"
293 "1: rep;stosl ; "
294 "popw %%es"
295 : "+D" (dst), "+c" (npad)
296 : "bdS" (video_segment),
297 "a" (0x07200720));
298 }
299
300 /* Restore cursor position */
301 if (saved.curx >= xs)
302 saved.curx = xs-1;
303 if (saved.cury >= ys)
304 saved.cury = ys-1;
305
306 initregs(&ireg);
307 ireg.ah = 0x02; /* Set cursor position */
308 ireg.dh = saved.cury;
309 ireg.dl = saved.curx;
310 intcall(0x10, &ireg, NULL);
311
312 store_cursor_position();
313 }
314
set_video(void)315 void set_video(void)
316 {
317 u16 mode = boot_params.hdr.vid_mode;
318
319 RESET_HEAP();
320
321 store_mode_params();
322 save_screen();
323 probe_cards(0);
324
325 for (;;) {
326 if (mode == ASK_VGA)
327 mode = mode_menu();
328
329 if (!set_mode(mode))
330 break;
331
332 printf("Undefined video mode number: %x\n", mode);
333 mode = ASK_VGA;
334 }
335 boot_params.hdr.vid_mode = mode;
336 vesa_store_edid();
337 store_mode_params();
338
339 if (do_restore)
340 restore_screen();
341 }
342