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