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
|
/* ----------------------------------------------------------------------- *
*
* Copyright 1999-2008 H. Peter Anvin - All Rights Reserved
* Copyright 2009 Intel Corporation; author: H. Peter Anvin
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* ----------------------------------------------------------------------- */
/*
* initvesa.c
*
* Query the VESA BIOS and select a 640x480x32 mode with local mapping
* support, if one exists.
*/
#include <inttypes.h>
#include <com32.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "vesa.h"
#include "mboot.h"
struct vesa_info vesa_info;
void set_graphics_mode(const struct multiboot_header *mbh,
struct multiboot_info *mbi)
{
com32sys_t rm;
uint16_t mode, bestmode, *mode_ptr;
struct vesa_general_info *gi;
struct vesa_mode_info *mi;
int pxf, bestpxf;
int wantx, wanty;
int err, besterr;
bool better;
addr_t viaddr;
/* Only do this if requested by the OS image */
if (!(mbh->flags & MULTIBOOT_VIDEO_MODE) || mbh->mode_type != 0)
return;
/* Allocate space in the bounce buffer for these structures */
gi = &((struct vesa_info *)__com32.cs_bounce)->gi;
mi = &((struct vesa_info *)__com32.cs_bounce)->mi;
memset(&rm, 0, sizeof rm);
memset(gi, 0, sizeof *gi);
gi->signature = VBE2_MAGIC; /* Get VBE2 extended data */
rm.eax.w[0] = 0x4F00; /* Get SVGA general information */
rm.edi.w[0] = OFFS(gi);
rm.es = SEG(gi);
__intcall(0x10, &rm, &rm);
if (rm.eax.w[0] != 0x004F)
return; /* Function call failed */
if (gi->signature != VESA_MAGIC)
return; /* No magic */
if (gi->version < 0x0102)
return; /* VESA 1.2+ required */
memcpy(&vesa_info.gi, gi, sizeof *gi);
/* Search for a suitable mode with a suitable color and memory model... */
mode_ptr = GET_PTR(gi->video_mode_ptr);
bestmode = 0;
bestpxf = 0;
wantx = mbh->width ? mbh->width : 0xffff;
wanty = mbh->height ? mbh->height : 0xffff;
besterr = wantx + wanty;
while ((mode = *mode_ptr++) != 0xFFFF) {
mode &= 0x1FF; /* The rest are attributes of sorts */
memset(mi, 0, sizeof *mi);
rm.eax.w[0] = 0x4F01; /* Get SVGA mode information */
rm.ecx.w[0] = mode;
rm.edi.w[0] = OFFS(mi);
rm.es = SEG(mi);
__intcall(0x10, &rm, &rm);
/* Must be a supported mode */
if (rm.eax.w[0] != 0x004f)
continue;
/* Must be an LFB color graphics mode supported by the hardware.
The bits tested are:
7 - linear frame buffer
4 - graphics mode
3 - color mode
1 - mode information available (mandatory in VBE 1.2+)
0 - mode supported by hardware
*/
if ((mi->mode_attr & 0x009b) != 0x009b)
continue;
/* We don't support multibank (interlaced memory) modes */
/*
* Note: The Bochs VESA BIOS (vbe.c 1.58 2006/08/19) violates the
* specification which states that banks == 1 for unbanked modes;
* fortunately it does report bank_size == 0 for those.
*/
if (mi->banks > 1 && mi->bank_size)
continue;
/* Must either be a packed-pixel mode or a direct color mode
(depending on VESA version ); must be a supported pixel format */
if (mi->bpp == 32 &&
(mi->memory_layout == 4 ||
(mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
mi->bpos == 0)))
pxf = 32;
else if (mi->bpp == 24 &&
(mi->memory_layout == 4 ||
(mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
mi->bpos == 0)))
pxf = 24;
else if (mi->bpp == 16 &&
(mi->memory_layout == 4 ||
(mi->memory_layout == 6 && mi->rpos == 11 && mi->gpos == 5 &&
mi->bpos == 0)))
pxf = 16;
else if (mi->bpp == 15 &&
(mi->memory_layout == 4 ||
(mi->memory_layout == 6 && mi->rpos == 10 && mi->gpos == 5 &&
mi->bpos == 0)))
pxf = 15;
else
continue;
better = false;
err = abs(mi->h_res - wantx) + abs(mi->v_res - wanty);
#define IS_GOOD(mi, bestx, besty) \
((mi)->h_res >= (bestx) && (mi)->v_res >= (besty))
if (!bestpxf)
better = true;
else if (!IS_GOOD(&vesa_info.mi, wantx, wanty) &&
IS_GOOD(mi, wantx, wanty))
/* This matches criteria, which the previous one didn't */
better = true;
else if (IS_GOOD(&vesa_info.mi, wantx, wanty) &&
!IS_GOOD(mi, wantx, wanty))
/* This doesn't match criteria, and the previous one did */
better = false;
else if (err < besterr)
better = true;
else if (err == besterr && (pxf == (int)mbh->depth || pxf > bestpxf))
better = true;
if (better) {
bestmode = mode;
bestpxf = pxf;
memcpy(&vesa_info.mi, mi, sizeof *mi);
}
}
if (!bestpxf)
return; /* No mode found */
mi = &vesa_info.mi;
mode = bestmode;
/* Now set video mode */
rm.eax.w[0] = 0x4F02; /* Set SVGA video mode */
mode |= 0x4000; /* Request linear framebuffer */
rm.ebx.w[0] = mode;
__intcall(0x10, &rm, &rm);
if (rm.eax.w[0] != 0x004F)
return; /* Failed to set mode */
mbi->flags |= MB_INFO_VIDEO_INFO;
mbi->vbe_mode = mode;
viaddr = map_data(&vesa_info, sizeof vesa_info, 4, 0);
mbi->vbe_control_info = viaddr + offsetof(struct vesa_info, gi);
mbi->vbe_mode_info = viaddr + offsetof(struct vesa_info, mi);
/* Get the VBE 2.x PM entry point if supported */
rm.eax.w[0] = 0x4F0A;
rm.ebx.w[0] = 0;
__intcall(0x10, &rm, &rm);
if (rm.eax.w[0] == 0x004F) {
mbi->vbe_interface_seg = rm.es;
mbi->vbe_interface_off = rm.edi.w[0];
mbi->vbe_interface_len = rm.ecx.w[0];
}
/* Tell syslinux we changed video mode */
rm.eax.w[0] = 0x0017; /* Report video mode change */
/* In theory this should be:
rm.ebx.w[0] = (mi->mode_attr & 4) ? 0x0007 : 0x000f;
However, that would assume all systems that claim to handle text
output in VESA modes actually do that... */
rm.ebx.w[0] = 0x000f;
rm.ecx.w[0] = vesa_info.mi.h_res;
rm.edx.w[0] = vesa_info.mi.v_res;
__intcall(0x22, &rm, NULL);
}
|
