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5e8ddcbe PA |
1 | /* -*- linux-c -*- ------------------------------------------------------- * |
2 | * | |
3 | * Copyright (C) 1991, 1992 Linus Torvalds | |
4 | * Copyright 2007 rPath, Inc. - All Rights Reserved | |
5 | * | |
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. | |
8 | * | |
9 | * ----------------------------------------------------------------------- */ | |
10 | ||
11 | /* | |
12 | * arch/i386/boot/video.c | |
13 | * | |
14 | * Select video mode | |
15 | */ | |
16 | ||
17 | #include "boot.h" | |
18 | #include "video.h" | |
19 | #include "vesa.h" | |
20 | ||
21 | /* | |
22 | * Mode list variables | |
23 | */ | |
24 | static struct card_info cards[]; /* List of cards to probe for */ | |
25 | ||
26 | /* | |
27 | * Common variables | |
28 | */ | |
29 | int adapter; /* 0=CGA/MDA/HGC, 1=EGA, 2=VGA+ */ | |
30 | u16 video_segment; | |
31 | int force_x, force_y; /* Don't query the BIOS for cols/rows */ | |
32 | ||
33 | int do_restore = 0; /* Screen contents changed during mode flip */ | |
34 | int graphic_mode; /* Graphic mode with linear frame buffer */ | |
35 | ||
36 | static void store_cursor_position(void) | |
37 | { | |
38 | u16 curpos; | |
39 | u16 ax, bx; | |
40 | ||
41 | ax = 0x0300; | |
42 | bx = 0; | |
43 | asm(INT10 | |
44 | : "=d" (curpos), "+a" (ax), "+b" (bx) | |
45 | : : "ecx", "esi", "edi"); | |
46 | ||
47 | boot_params.screen_info.orig_x = curpos; | |
48 | boot_params.screen_info.orig_y = curpos >> 8; | |
49 | } | |
50 | ||
51 | static void store_video_mode(void) | |
52 | { | |
53 | u16 ax, page; | |
54 | ||
55 | /* N.B.: the saving of the video page here is a bit silly, | |
56 | since we pretty much assume page 0 everywhere. */ | |
57 | ax = 0x0f00; | |
58 | asm(INT10 | |
59 | : "+a" (ax), "=b" (page) | |
60 | : : "ecx", "edx", "esi", "edi"); | |
61 | ||
62 | /* Not all BIOSes are clean with respect to the top bit */ | |
63 | boot_params.screen_info.orig_video_mode = ax & 0x7f; | |
362cea33 | 64 | boot_params.screen_info.orig_video_page = page >> 8; |
5e8ddcbe PA |
65 | } |
66 | ||
67 | /* | |
68 | * Store the video mode parameters for later usage by the kernel. | |
69 | * This is done by asking the BIOS except for the rows/columns | |
70 | * parameters in the default 80x25 mode -- these are set directly, | |
71 | * because some very obscure BIOSes supply insane values. | |
72 | */ | |
73 | static void store_mode_params(void) | |
74 | { | |
75 | u16 font_size; | |
76 | int x, y; | |
77 | ||
78 | /* For graphics mode, it is up to the mode-setting driver | |
79 | (currently only video-vesa.c) to store the parameters */ | |
80 | if (graphic_mode) | |
81 | return; | |
82 | ||
83 | store_cursor_position(); | |
84 | store_video_mode(); | |
85 | ||
86 | if (boot_params.screen_info.orig_video_mode == 0x07) { | |
87 | /* MDA, HGC, or VGA in monochrome mode */ | |
88 | video_segment = 0xb000; | |
89 | } else { | |
90 | /* CGA, EGA, VGA and so forth */ | |
91 | video_segment = 0xb800; | |
92 | } | |
93 | ||
94 | set_fs(0); | |
95 | font_size = rdfs16(0x485); /* Font size, BIOS area */ | |
96 | boot_params.screen_info.orig_video_points = font_size; | |
97 | ||
98 | x = rdfs16(0x44a); | |
99 | y = (adapter == ADAPTER_CGA) ? 25 : rdfs8(0x484)+1; | |
100 | ||
101 | if (force_x) | |
102 | x = force_x; | |
103 | if (force_y) | |
104 | y = force_y; | |
105 | ||
106 | boot_params.screen_info.orig_video_cols = x; | |
107 | boot_params.screen_info.orig_video_lines = y; | |
108 | } | |
109 | ||
110 | /* Probe the video drivers and have them generate their mode lists. */ | |
111 | static void probe_cards(int unsafe) | |
112 | { | |
113 | struct card_info *card; | |
114 | static u8 probed[2]; | |
115 | ||
116 | if (probed[unsafe]) | |
117 | return; | |
118 | ||
119 | probed[unsafe] = 1; | |
120 | ||
121 | for (card = video_cards; card < video_cards_end; card++) { | |
122 | if (card->unsafe == unsafe) { | |
123 | if (card->probe) | |
124 | card->nmodes = card->probe(); | |
125 | else | |
126 | card->nmodes = 0; | |
127 | } | |
128 | } | |
129 | } | |
130 | ||
131 | /* Test if a mode is defined */ | |
132 | int mode_defined(u16 mode) | |
133 | { | |
134 | struct card_info *card; | |
135 | struct mode_info *mi; | |
136 | int i; | |
137 | ||
138 | for (card = video_cards; card < video_cards_end; card++) { | |
139 | mi = card->modes; | |
140 | for (i = 0; i < card->nmodes; i++, mi++) { | |
141 | if (mi->mode == mode) | |
142 | return 1; | |
143 | } | |
144 | } | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | /* Set mode (without recalc) */ | |
3f662b3f | 150 | static int raw_set_mode(u16 mode, u16 *real_mode) |
5e8ddcbe PA |
151 | { |
152 | int nmode, i; | |
153 | struct card_info *card; | |
154 | struct mode_info *mi; | |
155 | ||
156 | /* Drop the recalc bit if set */ | |
157 | mode &= ~VIDEO_RECALC; | |
158 | ||
159 | /* Scan for mode based on fixed ID, position, or resolution */ | |
160 | nmode = 0; | |
161 | for (card = video_cards; card < video_cards_end; card++) { | |
162 | mi = card->modes; | |
163 | for (i = 0; i < card->nmodes; i++, mi++) { | |
164 | int visible = mi->x || mi->y; | |
165 | ||
166 | if ((mode == nmode && visible) || | |
167 | mode == mi->mode || | |
3f662b3f PA |
168 | mode == (mi->y << 8)+mi->x) { |
169 | *real_mode = mi->mode; | |
5e8ddcbe | 170 | return card->set_mode(mi); |
3f662b3f | 171 | } |
5e8ddcbe PA |
172 | |
173 | if (visible) | |
174 | nmode++; | |
175 | } | |
176 | } | |
177 | ||
178 | /* Nothing found? Is it an "exceptional" (unprobed) mode? */ | |
179 | for (card = video_cards; card < video_cards_end; card++) { | |
180 | if (mode >= card->xmode_first && | |
181 | mode < card->xmode_first+card->xmode_n) { | |
182 | struct mode_info mix; | |
3f662b3f | 183 | *real_mode = mix.mode = mode; |
5e8ddcbe PA |
184 | mix.x = mix.y = 0; |
185 | return card->set_mode(&mix); | |
186 | } | |
187 | } | |
188 | ||
189 | /* Otherwise, failure... */ | |
190 | return -1; | |
191 | } | |
192 | ||
193 | /* | |
194 | * Recalculate the vertical video cutoff (hack!) | |
195 | */ | |
196 | static void vga_recalc_vertical(void) | |
197 | { | |
198 | unsigned int font_size, rows; | |
199 | u16 crtc; | |
7ad37df0 | 200 | u8 pt, ov; |
5e8ddcbe PA |
201 | |
202 | set_fs(0); | |
203 | font_size = rdfs8(0x485); /* BIOS: font size (pixels) */ | |
204 | rows = force_y ? force_y : rdfs8(0x484)+1; /* Text rows */ | |
205 | ||
206 | rows *= font_size; /* Visible scan lines */ | |
207 | rows--; /* ... minus one */ | |
208 | ||
209 | crtc = vga_crtc(); | |
210 | ||
7ad37df0 PA |
211 | pt = in_idx(crtc, 0x11); |
212 | pt &= ~0x80; /* Unlock CR0-7 */ | |
213 | out_idx(pt, crtc, 0x11); | |
214 | ||
5e8ddcbe | 215 | out_idx((u8)rows, crtc, 0x12); /* Lower height register */ |
7ad37df0 | 216 | |
5e8ddcbe PA |
217 | ov = in_idx(crtc, 0x07); /* Overflow register */ |
218 | ov &= 0xbd; | |
219 | ov |= (rows >> (8-1)) & 0x02; | |
220 | ov |= (rows >> (9-6)) & 0x40; | |
221 | out_idx(ov, crtc, 0x07); | |
222 | } | |
223 | ||
224 | /* Set mode (with recalc if specified) */ | |
225 | static int set_mode(u16 mode) | |
226 | { | |
227 | int rv; | |
3f662b3f | 228 | u16 real_mode; |
5e8ddcbe PA |
229 | |
230 | /* Very special mode numbers... */ | |
231 | if (mode == VIDEO_CURRENT_MODE) | |
232 | return 0; /* Nothing to do... */ | |
233 | else if (mode == NORMAL_VGA) | |
234 | mode = VIDEO_80x25; | |
235 | else if (mode == EXTENDED_VGA) | |
236 | mode = VIDEO_8POINT; | |
237 | ||
3f662b3f | 238 | rv = raw_set_mode(mode, &real_mode); |
5e8ddcbe PA |
239 | if (rv) |
240 | return rv; | |
241 | ||
242 | if (mode & VIDEO_RECALC) | |
243 | vga_recalc_vertical(); | |
244 | ||
3f662b3f PA |
245 | /* Save the canonical mode number for the kernel, not |
246 | an alias, size specification or menu position */ | |
247 | boot_params.hdr.vid_mode = real_mode; | |
5e8ddcbe PA |
248 | return 0; |
249 | } | |
250 | ||
251 | static unsigned int get_entry(void) | |
252 | { | |
253 | char entry_buf[4]; | |
254 | int i, len = 0; | |
255 | int key; | |
256 | unsigned int v; | |
257 | ||
258 | do { | |
259 | key = getchar(); | |
260 | ||
261 | if (key == '\b') { | |
262 | if (len > 0) { | |
263 | puts("\b \b"); | |
264 | len--; | |
265 | } | |
266 | } else if ((key >= '0' && key <= '9') || | |
267 | (key >= 'A' && key <= 'Z') || | |
268 | (key >= 'a' && key <= 'z')) { | |
269 | if (len < sizeof entry_buf) { | |
270 | entry_buf[len++] = key; | |
271 | putchar(key); | |
272 | } | |
273 | } | |
274 | } while (key != '\r'); | |
275 | putchar('\n'); | |
276 | ||
277 | if (len == 0) | |
278 | return VIDEO_CURRENT_MODE; /* Default */ | |
279 | ||
280 | v = 0; | |
281 | for (i = 0; i < len; i++) { | |
282 | v <<= 4; | |
283 | key = entry_buf[i] | 0x20; | |
284 | v += (key > '9') ? key-'a'+10 : key-'0'; | |
285 | } | |
286 | ||
287 | return v; | |
288 | } | |
289 | ||
290 | static void display_menu(void) | |
291 | { | |
292 | struct card_info *card; | |
293 | struct mode_info *mi; | |
294 | char ch; | |
295 | int i; | |
296 | ||
297 | puts("Mode: COLSxROWS:\n"); | |
298 | ||
299 | ch = '0'; | |
300 | for (card = video_cards; card < video_cards_end; card++) { | |
301 | mi = card->modes; | |
302 | for (i = 0; i < card->nmodes; i++, mi++) { | |
303 | int visible = mi->x && mi->y; | |
304 | u16 mode_id = mi->mode ? mi->mode : | |
305 | (mi->y << 8)+mi->x; | |
306 | ||
307 | if (!visible) | |
308 | continue; /* Hidden mode */ | |
309 | ||
310 | printf("%c %04X %3dx%-3d %s\n", | |
311 | ch, mode_id, mi->x, mi->y, card->card_name); | |
312 | ||
313 | if (ch == '9') | |
314 | ch = 'a'; | |
315 | else if (ch == 'z' || ch == ' ') | |
316 | ch = ' '; /* Out of keys... */ | |
317 | else | |
318 | ch++; | |
319 | } | |
320 | } | |
321 | } | |
322 | ||
323 | #define H(x) ((x)-'a'+10) | |
324 | #define SCAN ((H('s')<<12)+(H('c')<<8)+(H('a')<<4)+H('n')) | |
325 | ||
326 | static unsigned int mode_menu(void) | |
327 | { | |
328 | int key; | |
329 | unsigned int sel; | |
330 | ||
331 | puts("Press <ENTER> to see video modes available, " | |
332 | "<SPACE> to continue, or wait 30 sec\n"); | |
333 | ||
334 | kbd_flush(); | |
335 | while (1) { | |
336 | key = getchar_timeout(); | |
337 | if (key == ' ' || key == 0) | |
338 | return VIDEO_CURRENT_MODE; /* Default */ | |
339 | if (key == '\r') | |
340 | break; | |
341 | putchar('\a'); /* Beep! */ | |
342 | } | |
343 | ||
344 | ||
345 | for (;;) { | |
346 | display_menu(); | |
347 | ||
348 | puts("Enter a video mode or \"scan\" to scan for " | |
349 | "additional modes: "); | |
350 | sel = get_entry(); | |
351 | if (sel != SCAN) | |
352 | return sel; | |
353 | ||
354 | probe_cards(1); | |
355 | } | |
356 | } | |
357 | ||
358 | #ifdef CONFIG_VIDEO_RETAIN | |
359 | /* Save screen content to the heap */ | |
360 | struct saved_screen { | |
361 | int x, y; | |
362 | int curx, cury; | |
363 | u16 *data; | |
364 | } saved; | |
365 | ||
366 | static void save_screen(void) | |
367 | { | |
368 | /* Should be called after store_mode_params() */ | |
369 | saved.x = boot_params.screen_info.orig_video_cols; | |
370 | saved.y = boot_params.screen_info.orig_video_lines; | |
371 | saved.curx = boot_params.screen_info.orig_x; | |
372 | saved.cury = boot_params.screen_info.orig_y; | |
373 | ||
e6e1ace9 | 374 | if (!heap_free(saved.x*saved.y*sizeof(u16)+512)) |
5e8ddcbe PA |
375 | return; /* Not enough heap to save the screen */ |
376 | ||
377 | saved.data = GET_HEAP(u16, saved.x*saved.y); | |
378 | ||
379 | set_fs(video_segment); | |
380 | copy_from_fs(saved.data, 0, saved.x*saved.y*sizeof(u16)); | |
381 | } | |
382 | ||
383 | static void restore_screen(void) | |
384 | { | |
385 | /* Should be called after store_mode_params() */ | |
386 | int xs = boot_params.screen_info.orig_video_cols; | |
387 | int ys = boot_params.screen_info.orig_video_lines; | |
388 | int y; | |
389 | addr_t dst = 0; | |
390 | u16 *src = saved.data; | |
391 | u16 ax, bx, dx; | |
392 | ||
393 | if (graphic_mode) | |
394 | return; /* Can't restore onto a graphic mode */ | |
395 | ||
396 | if (!src) | |
397 | return; /* No saved screen contents */ | |
398 | ||
399 | /* Restore screen contents */ | |
400 | ||
401 | set_fs(video_segment); | |
402 | for (y = 0; y < ys; y++) { | |
403 | int npad; | |
404 | ||
405 | if (y < saved.y) { | |
406 | int copy = (xs < saved.x) ? xs : saved.x; | |
407 | copy_to_fs(dst, src, copy*sizeof(u16)); | |
408 | dst += copy*sizeof(u16); | |
409 | src += saved.x; | |
410 | npad = (xs < saved.x) ? 0 : xs-saved.x; | |
411 | } else { | |
412 | npad = xs; | |
413 | } | |
414 | ||
415 | /* Writes "npad" blank characters to | |
416 | video_segment:dst and advances dst */ | |
417 | asm volatile("pushw %%es ; " | |
418 | "movw %2,%%es ; " | |
419 | "shrw %%cx ; " | |
420 | "jnc 1f ; " | |
421 | "stosw \n\t" | |
422 | "1: rep;stosl ; " | |
423 | "popw %%es" | |
424 | : "+D" (dst), "+c" (npad) | |
5593eaa8 | 425 | : "bdS" (video_segment), |
5e8ddcbe PA |
426 | "a" (0x07200720)); |
427 | } | |
428 | ||
429 | /* Restore cursor position */ | |
430 | ax = 0x0200; /* Set cursor position */ | |
431 | bx = 0; /* Page number (<< 8) */ | |
432 | dx = (saved.cury << 8)+saved.curx; | |
433 | asm volatile(INT10 | |
434 | : "+a" (ax), "+b" (bx), "+d" (dx) | |
435 | : : "ecx", "esi", "edi"); | |
436 | } | |
437 | #else | |
438 | #define save_screen() ((void)0) | |
439 | #define restore_screen() ((void)0) | |
440 | #endif | |
441 | ||
442 | void set_video(void) | |
443 | { | |
444 | u16 mode = boot_params.hdr.vid_mode; | |
445 | ||
446 | RESET_HEAP(); | |
447 | ||
448 | store_mode_params(); | |
449 | save_screen(); | |
450 | probe_cards(0); | |
451 | ||
452 | for (;;) { | |
453 | if (mode == ASK_VGA) | |
454 | mode = mode_menu(); | |
455 | ||
456 | if (!set_mode(mode)) | |
457 | break; | |
458 | ||
459 | printf("Undefined video mode number: %x\n", mode); | |
460 | mode = ASK_VGA; | |
461 | } | |
462 | vesa_store_edid(); | |
463 | store_mode_params(); | |
464 | ||
465 | if (do_restore) | |
466 | restore_screen(); | |
467 | } |