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 <uapi/asm/boot.h>
17
18#include "boot.h"
19#include "video.h"
20#include "vesa.h"
21
22static u16 video_segment;
23
24static void store_cursor_position(void)
25{
26 struct biosregs ireg, oreg;
27
28 initregs(&ireg);
29 ireg.ah = 0x03;
30 intcall(0x10, &ireg, &oreg);
31
32 boot_params.screen_info.orig_x = oreg.dl;
33 boot_params.screen_info.orig_y = oreg.dh;
34
35 if (oreg.ch & 0x20)
36 boot_params.screen_info.flags |= VIDEO_FLAGS_NOCURSOR;
37
38 if ((oreg.ch & 0x1f) > (oreg.cl & 0x1f))
39 boot_params.screen_info.flags |= VIDEO_FLAGS_NOCURSOR;
40}
41
42static void store_video_mode(void)
43{
44 struct biosregs ireg, oreg;
45
46 /* N.B.: the saving of the video page here is a bit silly,
47 since we pretty much assume page 0 everywhere. */
48 initregs(&ireg);
49 ireg.ah = 0x0f;
50 intcall(0x10, &ireg, &oreg);
51
52 /* Not all BIOSes are clean with respect to the top bit */
53 boot_params.screen_info.orig_video_mode = oreg.al & 0x7f;
54 boot_params.screen_info.orig_video_page = oreg.bh;
55}
56
57/*
58 * Store the video mode parameters for later usage by the kernel.
59 * This is done by asking the BIOS except for the rows/columns
60 * parameters in the default 80x25 mode -- these are set directly,
61 * because some very obscure BIOSes supply insane values.
62 */
63static void store_mode_params(void)
64{
65 u16 font_size;
66 int x, y;
67
68 /* For graphics mode, it is up to the mode-setting driver
69 (currently only video-vesa.c) to store the parameters */
70 if (graphic_mode)
71 return;
72
73 store_cursor_position();
74 store_video_mode();
75
76 if (boot_params.screen_info.orig_video_mode == 0x07) {
77 /* MDA, HGC, or VGA in monochrome mode */
78 video_segment = 0xb000;
79 } else {
80 /* CGA, EGA, VGA and so forth */
81 video_segment = 0xb800;
82 }
83
84 set_fs(0);
85 font_size = rdfs16(0x485); /* Font size, BIOS area */
86 boot_params.screen_info.orig_video_points = font_size;
87
88 x = rdfs16(0x44a);
89 y = (adapter == ADAPTER_CGA) ? 25 : rdfs8(0x484)+1;
90
91 if (force_x)
92 x = force_x;
93 if (force_y)
94 y = force_y;
95
96 boot_params.screen_info.orig_video_cols = x;
97 boot_params.screen_info.orig_video_lines = y;
98}
99
100static unsigned int get_entry(void)
101{
102 char entry_buf[4];
103 int i, len = 0;
104 int key;
105 unsigned int v;
106
107 do {
108 key = getchar();
109
110 if (key == '\b') {
111 if (len > 0) {
112 puts("\b \b");
113 len--;
114 }
115 } else if ((key >= '0' && key <= '9') ||
116 (key >= 'A' && key <= 'Z') ||
117 (key >= 'a' && key <= 'z')) {
118 if (len < sizeof(entry_buf)) {
119 entry_buf[len++] = key;
120 putchar(key);
121 }
122 }
123 } while (key != '\r');
124 putchar('\n');
125
126 if (len == 0)
127 return VIDEO_CURRENT_MODE; /* Default */
128
129 v = 0;
130 for (i = 0; i < len; i++) {
131 v <<= 4;
132 key = entry_buf[i] | 0x20;
133 v += (key > '9') ? key-'a'+10 : key-'0';
134 }
135
136 return v;
137}
138
139static void display_menu(void)
140{
141 struct card_info *card;
142 struct mode_info *mi;
143 char ch;
144 int i;
145 int nmodes;
146 int modes_per_line;
147 int col;
148
149 nmodes = 0;
150 for (card = video_cards; card < video_cards_end; card++)
151 nmodes += card->nmodes;
152
153 modes_per_line = 1;
154 if (nmodes >= 20)
155 modes_per_line = 3;
156
157 for (col = 0; col < modes_per_line; col++)
158 puts("Mode: Resolution: Type: ");
159 putchar('\n');
160
161 col = 0;
162 ch = '0';
163 for (card = video_cards; card < video_cards_end; card++) {
164 mi = card->modes;
165 for (i = 0; i < card->nmodes; i++, mi++) {
166 char resbuf[32];
167 int visible = mi->x && mi->y;
168 u16 mode_id = mi->mode ? mi->mode :
169 (mi->y << 8)+mi->x;
170
171 if (!visible)
172 continue; /* Hidden mode */
173
174 if (mi->depth)
175 sprintf(resbuf, "%dx%d", mi->y, mi->depth);
176 else
177 sprintf(resbuf, "%d", mi->y);
178
179 printf("%c %03X %4dx%-7s %-6s",
180 ch, mode_id, mi->x, resbuf, card->card_name);
181 col++;
182 if (col >= modes_per_line) {
183 putchar('\n');
184 col = 0;
185 }
186
187 if (ch == '9')
188 ch = 'a';
189 else if (ch == 'z' || ch == ' ')
190 ch = ' '; /* Out of keys... */
191 else
192 ch++;
193 }
194 }
195 if (col)
196 putchar('\n');
197}
198
199#define H(x) ((x)-'a'+10)
200#define SCAN ((H('s')<<12)+(H('c')<<8)+(H('a')<<4)+H('n'))
201
202static unsigned int mode_menu(void)
203{
204 int key;
205 unsigned int sel;
206
207 puts("Press <ENTER> to see video modes available, "
208 "<SPACE> to continue, or wait 30 sec\n");
209
210 kbd_flush();
211 while (1) {
212 key = getchar_timeout();
213 if (key == ' ' || key == 0)
214 return VIDEO_CURRENT_MODE; /* Default */
215 if (key == '\r')
216 break;
217 putchar('\a'); /* Beep! */
218 }
219
220
221 for (;;) {
222 display_menu();
223
224 puts("Enter a video mode or \"scan\" to scan for "
225 "additional modes: ");
226 sel = get_entry();
227 if (sel != SCAN)
228 return sel;
229
230 probe_cards(1);
231 }
232}
233
234/* Save screen content to the heap */
235static struct saved_screen {
236 int x, y;
237 int curx, cury;
238 u16 *data;
239} saved;
240
241static void save_screen(void)
242{
243 /* Should be called after store_mode_params() */
244 saved.x = boot_params.screen_info.orig_video_cols;
245 saved.y = boot_params.screen_info.orig_video_lines;
246 saved.curx = boot_params.screen_info.orig_x;
247 saved.cury = boot_params.screen_info.orig_y;
248
249 if (!heap_free(saved.x*saved.y*sizeof(u16)+512))
250 return; /* Not enough heap to save the screen */
251
252 saved.data = GET_HEAP(u16, saved.x*saved.y);
253
254 set_fs(video_segment);
255 copy_from_fs(saved.data, 0, saved.x*saved.y*sizeof(u16));
256}
257
258static void restore_screen(void)
259{
260 /* Should be called after store_mode_params() */
261 int xs = boot_params.screen_info.orig_video_cols;
262 int ys = boot_params.screen_info.orig_video_lines;
263 int y;
264 addr_t dst = 0;
265 u16 *src = saved.data;
266 struct biosregs ireg;
267
268 if (graphic_mode)
269 return; /* Can't restore onto a graphic mode */
270
271 if (!src)
272 return; /* No saved screen contents */
273
274 /* Restore screen contents */
275
276 set_fs(video_segment);
277 for (y = 0; y < ys; y++) {
278 int npad;
279
280 if (y < saved.y) {
281 int copy = (xs < saved.x) ? xs : saved.x;
282 copy_to_fs(dst, src, copy*sizeof(u16));
283 dst += copy*sizeof(u16);
284 src += saved.x;
285 npad = (xs < saved.x) ? 0 : xs-saved.x;
286 } else {
287 npad = xs;
288 }
289
290 /* Writes "npad" blank characters to
291 video_segment:dst and advances dst */
292 asm volatile("pushw %%es ; "
293 "movw %2,%%es ; "
294 "shrw %%cx ; "
295 "jnc 1f ; "
296 "stosw \n\t"
297 "1: rep;stosl ; "
298 "popw %%es"
299 : "+D" (dst), "+c" (npad)
300 : "bdS" (video_segment),
301 "a" (0x07200720));
302 }
303
304 /* Restore cursor position */
305 if (saved.curx >= xs)
306 saved.curx = xs-1;
307 if (saved.cury >= ys)
308 saved.cury = ys-1;
309
310 initregs(&ireg);
311 ireg.ah = 0x02; /* Set cursor position */
312 ireg.dh = saved.cury;
313 ireg.dl = saved.curx;
314 intcall(0x10, &ireg, NULL);
315
316 store_cursor_position();
317}
318
319void set_video(void)
320{
321 u16 mode = boot_params.hdr.vid_mode;
322
323 RESET_HEAP();
324
325 store_mode_params();
326 save_screen();
327 probe_cards(0);
328
329 for (;;) {
330 if (mode == ASK_VGA)
331 mode = mode_menu();
332
333 if (!set_mode(mode))
334 break;
335
336 printf("Undefined video mode number: %x\n", mode);
337 mode = ASK_VGA;
338 }
339 boot_params.hdr.vid_mode = mode;
340 vesa_store_edid();
341 store_mode_params();
342
343 if (do_restore)
344 restore_screen();
345}
346