1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 1999-2008 H. Peter Anvin - All Rights Reserved
4 * Copyright 2009 Intel Corporation; author: H. Peter Anvin
5 *
6 * Permission is hereby granted, free of charge, to any person
7 * obtaining a copy of this software and associated documentation
8 * files (the "Software"), to deal in the Software without
9 * restriction, including without limitation the rights to use,
10 * copy, modify, merge, publish, distribute, sublicense, and/or
11 * sell copies of the Software, and to permit persons to whom
12 * the Software is furnished to do so, subject to the following
13 * conditions:
14 *
15 * The above copyright notice and this permission notice shall
16 * be included in all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
20 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
22 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
23 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 * OTHER DEALINGS IN THE SOFTWARE.
26 *
27 * ----------------------------------------------------------------------- */
28
29 /*
30 * initvesa.c
31 *
32 * Query the VESA BIOS and select a 640x480x32 mode with local mapping
33 * support, if one exists.
34 */
35
36 #include <inttypes.h>
37 #include <com32.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <limits.h>
41 #include <graphics.h>
42
43 #include "vesa.h"
44 #include "mboot.h"
45
46 struct vesa_info vesa_info;
47
set_graphics_mode(const struct multiboot_header * mbh,struct multiboot_info * mbi)48 void set_graphics_mode(const struct multiboot_header *mbh,
49 struct multiboot_info *mbi)
50 {
51 com32sys_t rm;
52 uint16_t mode, bestmode, *mode_ptr;
53 struct vesa_general_info *gi;
54 struct vesa_mode_info *mi;
55 int pxf, bestpxf;
56 int wantx, wanty;
57 int err, besterr;
58 bool better;
59 addr_t viaddr;
60
61 /* Only do this if requested by the OS image */
62 if (!(mbh->flags & MULTIBOOT_VIDEO_MODE) || mbh->mode_type != 0)
63 return;
64
65 gi = lmalloc(sizeof *gi);
66 if (!gi)
67 return;
68
69 mi = lmalloc(sizeof *mi);
70 if (!mi)
71 goto out;
72
73 memset(&rm, 0, sizeof rm);
74 memset(gi, 0, sizeof *gi);
75
76 gi->signature = VBE2_MAGIC; /* Get VBE2 extended data */
77 rm.eax.w[0] = 0x4F00; /* Get SVGA general information */
78 rm.edi.w[0] = OFFS(gi);
79 rm.es = SEG(gi);
80 __intcall(0x10, &rm, &rm);
81
82 if (rm.eax.w[0] != 0x004F)
83 goto out; /* Function call failed */
84 if (gi->signature != VESA_MAGIC)
85 goto out; /* No magic */
86 if (gi->version < 0x0102)
87 goto out; /* VESA 1.2+ required */
88
89 memcpy(&vesa_info.gi, gi, sizeof *gi);
90
91 /* Search for a suitable mode with a suitable color and memory model... */
92
93 mode_ptr = GET_PTR(gi->video_mode_ptr);
94 bestmode = 0;
95 bestpxf = 0;
96 wantx = mbh->width ? mbh->width : 0xffff;
97 wanty = mbh->height ? mbh->height : 0xffff;
98 besterr = wantx + wanty;
99
100 while ((mode = *mode_ptr++) != 0xFFFF) {
101 mode &= 0x1FF; /* The rest are attributes of sorts */
102
103 memset(&rm, 0, sizeof rm);
104 memset(mi, 0, sizeof *mi);
105 rm.eax.w[0] = 0x4F01; /* Get SVGA mode information */
106 rm.ecx.w[0] = mode;
107 rm.edi.w[0] = OFFS(mi);
108 rm.es = SEG(mi);
109 __intcall(0x10, &rm, &rm);
110
111 /* Must be a supported mode */
112 if (rm.eax.w[0] != 0x004f)
113 continue;
114
115 /* Must be an LFB color graphics mode supported by the hardware.
116
117 The bits tested are:
118 7 - linear frame buffer
119 4 - graphics mode
120 3 - color mode
121 1 - mode information available (mandatory in VBE 1.2+)
122 0 - mode supported by hardware
123 */
124 if ((mi->mode_attr & 0x009b) != 0x009b)
125 continue;
126
127 /* We don't support multibank (interlaced memory) modes */
128 /*
129 * Note: The Bochs VESA BIOS (vbe.c 1.58 2006/08/19) violates the
130 * specification which states that banks == 1 for unbanked modes;
131 * fortunately it does report bank_size == 0 for those.
132 */
133 if (mi->banks > 1 && mi->bank_size)
134 continue;
135
136 /* Must either be a packed-pixel mode or a direct color mode
137 (depending on VESA version ); must be a supported pixel format */
138
139 if (mi->bpp == 32 &&
140 (mi->memory_layout == 4 ||
141 (mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
142 mi->bpos == 0)))
143 pxf = 32;
144 else if (mi->bpp == 24 &&
145 (mi->memory_layout == 4 ||
146 (mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
147 mi->bpos == 0)))
148 pxf = 24;
149 else if (mi->bpp == 16 &&
150 (mi->memory_layout == 4 ||
151 (mi->memory_layout == 6 && mi->rpos == 11 && mi->gpos == 5 &&
152 mi->bpos == 0)))
153 pxf = 16;
154 else if (mi->bpp == 15 &&
155 (mi->memory_layout == 4 ||
156 (mi->memory_layout == 6 && mi->rpos == 10 && mi->gpos == 5 &&
157 mi->bpos == 0)))
158 pxf = 15;
159 else
160 continue;
161
162 better = false;
163 err = abs(mi->h_res - wantx) + abs(mi->v_res - wanty);
164
165 #define IS_GOOD(mi, bestx, besty) \
166 ((mi)->h_res >= (bestx) && (mi)->v_res >= (besty))
167
168 if (!bestpxf)
169 better = true;
170 else if (!IS_GOOD(&vesa_info.mi, wantx, wanty) &&
171 IS_GOOD(mi, wantx, wanty))
172 /* This matches criteria, which the previous one didn't */
173 better = true;
174 else if (IS_GOOD(&vesa_info.mi, wantx, wanty) &&
175 !IS_GOOD(mi, wantx, wanty))
176 /* This doesn't match criteria, and the previous one did */
177 better = false;
178 else if (err < besterr)
179 better = true;
180 else if (err == besterr && (pxf == (int)mbh->depth || pxf > bestpxf))
181 better = true;
182
183 if (better) {
184 bestmode = mode;
185 bestpxf = pxf;
186 memcpy(&vesa_info.mi, mi, sizeof *mi);
187 }
188 }
189
190 if (!bestpxf)
191 goto out; /* No mode found */
192
193 mi = &vesa_info.mi;
194 mode = bestmode;
195
196 /* Now set video mode */
197 memset(&rm, 0, sizeof rm);
198 rm.eax.w[0] = 0x4F02; /* Set SVGA video mode */
199 mode |= 0x4000; /* Request linear framebuffer */
200 rm.ebx.w[0] = mode;
201 __intcall(0x10, &rm, &rm);
202 if (rm.eax.w[0] != 0x004F)
203 goto out; /* Failed to set mode */
204
205 mbi->flags |= MB_INFO_VIDEO_INFO;
206 mbi->vbe_mode = mode;
207 viaddr = map_data(&vesa_info, sizeof vesa_info, 4, 0);
208 mbi->vbe_control_info = viaddr + offsetof(struct vesa_info, gi);
209 mbi->vbe_mode_info = viaddr + offsetof(struct vesa_info, mi);
210
211 /* Get the VBE 2.x PM entry point if supported */
212 rm.eax.w[0] = 0x4F0A;
213 rm.ebx.w[0] = 0;
214 __intcall(0x10, &rm, &rm);
215 if (rm.eax.w[0] == 0x004F) {
216 mbi->vbe_interface_seg = rm.es;
217 mbi->vbe_interface_off = rm.edi.w[0];
218 mbi->vbe_interface_len = rm.ecx.w[0];
219 }
220
221 /* In theory this should be:
222 *
223 * UsingVga = (mi->mode_attr & 4) ? 0x0007 : 0x000f;
224 *
225 * However, that would assume all systems that claim to handle text
226 * output in VESA modes actually do that...
227 */
228 graphics_using_vga(0x0F, vesa_info.mi.h_res, vesa_info.mi.v_res);
229
230 out:
231 lfree(mi);
232 lfree(gi);
233 }
234