aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/boot/video-vesa.c
blob: 19219071071023e631518e102c4dbcc7481dea17 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright (C) 1991, 1992 Linus Torvalds
 *   Copyright 2007 rPath, Inc. - All Rights Reserved
 *
 *   This file is part of the Linux kernel, and is made available under
 *   the terms of the GNU General Public License version 2.
 *
 * ----------------------------------------------------------------------- */

/*
 * arch/i386/boot/video-vesa.c
 *
 * VESA text modes
 */

#include "boot.h"
#include "video.h"
#include "vesa.h"

/* VESA information */
static struct vesa_general_info vginfo;
static struct vesa_mode_info vminfo;

__videocard video_vesa;

static void vesa_store_mode_params_graphics(void);

static int vesa_probe(void)
{
#if defined(CONFIG_VIDEO_VESA) || defined(CONFIG_FIRMWARE_EDID)
	u16 ax, cx, di;
	u16 mode;
	addr_t mode_ptr;
	struct mode_info *mi;
	int nmodes = 0;

	video_vesa.modes = GET_HEAP(struct mode_info, 0);

	vginfo.signature = VBE2_MAGIC;

	ax = 0x4f00;
	di = (size_t)&vginfo;
	asm(INT10
	    : "+a" (ax), "+D" (di), "=m" (vginfo)
	    : : "ebx", "ecx", "edx", "esi");

	if (ax != 0x004f ||
	    vginfo.signature != VESA_MAGIC ||
	    vginfo.version < 0x0102)
		return 0;	/* Not present */
#endif /* CONFIG_VIDEO_VESA || CONFIG_FIRMWARE_EDID */
#ifdef CONFIG_VIDEO_VESA
	set_fs(vginfo.video_mode_ptr.seg);
	mode_ptr = vginfo.video_mode_ptr.off;

	while ((mode = rdfs16(mode_ptr)) != 0xffff) {
		mode_ptr += 2;

		if (heap_free() < sizeof(struct mode_info))
			break;	/* Heap full, can't save mode info */

		if (mode & ~0x1ff)
			continue;

		memset(&vminfo, 0, sizeof vminfo); /* Just in case... */

		ax = 0x4f01;
		cx = mode;
		di = (size_t)&vminfo;
		asm(INT10
		    : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
		    : : "ebx", "edx", "esi");

		if (ax != 0x004f)
			continue;

		if ((vminfo.mode_attr & 0x15) == 0x05) {
			/* Text Mode, TTY BIOS supported,
			   supported by hardware */
			mi = GET_HEAP(struct mode_info, 1);
			mi->mode = mode + VIDEO_FIRST_VESA;
			mi->x    = vminfo.h_res;
			mi->y    = vminfo.v_res;
			nmodes++;
		} else if ((vminfo.mode_attr & 0x99) == 0x99) {
#ifdef CONFIG_FB
			/* Graphics mode, color, linear frame buffer
			   supported -- register the mode but hide from
			   the menu.  Only do this if framebuffer is
			   configured, however, otherwise the user will
			   be left without a screen. */
			mi = GET_HEAP(struct mode_info, 1);
			mi->mode = mode + VIDEO_FIRST_VESA;
			mi->x = mi->y = 0;
			nmodes++;
#endif
		}
	}

	return nmodes;
#else
	return 0;
#endif /* CONFIG_VIDEO_VESA */
}

static int vesa_set_mode(struct mode_info *mode)
{
	u16 ax, bx, cx, di;
	int is_graphic;
	u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;

	memset(&vminfo, 0, sizeof vminfo); /* Just in case... */

	ax = 0x4f01;
	cx = vesa_mode;
	di = (size_t)&vminfo;
	asm(INT10
	    : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
	    : : "ebx", "edx", "esi");

	if (ax != 0x004f)
		return -1;

	if ((vminfo.mode_attr & 0x15) == 0x05) {
		/* It's a supported text mode */
		is_graphic = 0;
	} else if ((vminfo.mode_attr & 0x99) == 0x99) {
		/* It's a graphics mode with linear frame buffer */
		is_graphic = 1;
		vesa_mode |= 0x4000; /* Request linear frame buffer */
	} else {
		return -1;	/* Invalid mode */
	}


	ax = 0x4f02;
	bx = vesa_mode;
	di = 0;
	asm volatile(INT10
		     : "+a" (ax), "+b" (bx), "+D" (di)
		     : : "ecx", "edx", "esi");

	if (ax != 0x004f)
		return -1;

	graphic_mode = is_graphic;
	if (!is_graphic) {
		/* Text mode */
		force_x = mode->x;
		force_y = mode->y;
		do_restore = 1;
	} else {
		/* Graphics mode */
		vesa_store_mode_params_graphics();
	}

	return 0;
}


/* Switch DAC to 8-bit mode */
static void vesa_dac_set_8bits(void)
{
	u8 dac_size = 6;

	/* If possible, switch the DAC to 8-bit mode */
	if (vginfo.capabilities & 1) {
		u16 ax, bx;

		ax = 0x4f08;
		bx = 0x0800;
		asm volatile(INT10
			     : "+a" (ax), "+b" (bx)
			     : : "ecx", "edx", "esi", "edi");

		if (ax == 0x004f)
			dac_size = bx >> 8;
	}

	/* Set the color sizes to the DAC size, and offsets to 0 */
	boot_params.screen_info.red_size = dac_size;
	boot_params.screen_info.green_size = dac_size;
	boot_params.screen_info.blue_size = dac_size;
	boot_params.screen_info.rsvd_size = dac_size;

	boot_params.screen_info.red_pos = 0;
	boot_params.screen_info.green_pos = 0;
	boot_params.screen_info.blue_pos = 0;
	boot_params.screen_info.rsvd_pos = 0;
}

/* Save the VESA protected mode info */
static void vesa_store_pm_info(void)
{
	u16 ax, bx, di, es;

	ax = 0x4f0a;
	bx = di = 0;
	asm("pushw %%es; "INT10"; movw %%es,%0; popw %%es"
	    : "=d" (es), "+a" (ax), "+b" (bx), "+D" (di)
	    : : "ecx", "esi");

	if (ax != 0x004f)
		return;

	boot_params.screen_info.vesapm_seg = es;
	boot_params.screen_info.vesapm_off = di;
}

/*
 * Save video mode parameters for graphics mode
 */
static void vesa_store_mode_params_graphics(void)
{
	/* Tell the kernel we're in VESA graphics mode */
	boot_params.screen_info.orig_video_isVGA = 0x23;

	/* Mode parameters */
	boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
	boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
	boot_params.screen_info.lfb_width = vminfo.h_res;
	boot_params.screen_info.lfb_height = vminfo.v_res;
	boot_params.screen_info.lfb_depth = vminfo.bpp;
	boot_params.screen_info.pages = vminfo.image_planes;
	boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
	memcpy(&boot_params.screen_info.red_size,
	       &vminfo.rmask, 8);

	/* General parameters */
	boot_params.screen_info.lfb_size = vginfo.total_memory;

	if (vminfo.bpp <= 8)
		vesa_dac_set_8bits();

	vesa_store_pm_info();
}

/*
 * Save EDID information for the kernel; this is invoked, separately,
 * after mode-setting.
 */
void vesa_store_edid(void)
{
#ifdef CONFIG_FIRMWARE_EDID
	u16 ax, bx, cx, dx, di;

	/* Apparently used as a nonsense token... */
	memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);

	if (vginfo.version < 0x0200)
		return;		/* EDID requires VBE 2.0+ */

	ax = 0x4f15;		/* VBE DDC */
	bx = 0x0000;		/* Report DDC capabilities */
	cx = 0;			/* Controller 0 */
	di = 0;			/* ES:DI must be 0 by spec */

	/* Note: The VBE DDC spec is different from the main VESA spec;
	   we genuinely have to assume all registers are destroyed here. */

	asm("pushw %%es; movw %2,%%es; "INT10"; popw %%es"
	    : "+a" (ax), "+b" (bx)
	    :  "c" (cx), "D" (di)
	    : "esi");

	if (ax != 0x004f)
		return;		/* No EDID */

	/* BH = time in seconds to transfer EDD information */
	/* BL = DDC level supported */

	ax = 0x4f15;		/* VBE DDC */
	bx = 0x0001;		/* Read EDID */
	cx = 0;			/* Controller 0 */
	dx = 0;			/* EDID block number */
	di =(size_t) &boot_params.edid_info; /* (ES:)Pointer to block */
	asm(INT10
	    : "+a" (ax), "+b" (bx), "+d" (dx), "=m" (boot_params.edid_info)
	    : "c" (cx), "D" (di)
	    : "esi");
#endif /* CONFIG_FIRMWARE_EDID */
}

__videocard video_vesa =
{
	.card_name	= "VESA",
	.probe		= vesa_probe,
	.set_mode	= vesa_set_mode,
	.xmode_first	= VIDEO_FIRST_VESA,
	.xmode_n	= 0x200,
};