vbeinfo

view src/vbe.c @ 4:d2c44edd8b77

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print the framebuffer address
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 07 Jan 2019 13:52:58 +0200
parents 4b33fa83e381
children
line source
1 #include <stdio.h>
2 #include <string.h>
3 #include <conio.h>
4 #include "vbe.h"
5 #include "dpmi.h"
6 #include "inttypes.h"
7
8 #ifdef __DJGPP__
9 #include <pc.h>
10 #include <sys/nearptr.h>
11
12 #define SEG_ADDR(s) (((uint32_t)(s) << 4) - __djgpp_base_address)
13
14 #define outp(p, v) outportb(p, v)
15 #else
16 #define SEG_ADDR(s) ((uint32_t)(s) << 4)
17 #endif
18
19 /* VGA DAC registers used for palette setting in 8bpp modes */
20 #define VGA_DAC_STATE 0x3c7
21 #define VGA_DAC_ADDR_RD 0x3c7
22 #define VGA_DAC_ADDR_WR 0x3c8
23 #define VGA_DAC_DATA 0x3c9
24
25 #define MODE_LFB (1 << 14)
26
27
28 struct vbe_info *vbe_get_info(void)
29 {
30 static uint16_t info_block_seg, info_block_selector;
31 static struct vbe_info *info;
32 struct dpmi_real_regs regs;
33
34 if(!info) {
35 /* allocate 32 paragraphs (512 bytes) */
36 info_block_seg = dpmi_alloc(32, &info_block_selector);
37 info = (struct vbe_info*)SEG_ADDR(info_block_seg);
38 }
39
40 memcpy(info->sig, "VBE2", 4);
41
42 memset(&regs, 0, sizeof regs);
43 regs.es = info_block_seg;
44 regs.eax = 0x4f00;
45
46 dpmi_real_int(0x10, &regs);
47
48 return info;
49 }
50
51 struct vbe_mode_info *vbe_get_mode_info(int mode)
52 {
53 static uint16_t mode_info_seg, mode_info_selector;
54 static struct vbe_mode_info *mi;
55 struct dpmi_real_regs regs;
56
57 if(!mi) {
58 /* allocate 16 paragraphs (256 bytes) */
59 mode_info_seg = dpmi_alloc(16, &mode_info_selector);
60 mi = (struct vbe_mode_info*)SEG_ADDR(mode_info_seg);
61 }
62
63 memset(&regs, 0, sizeof regs);
64 regs.es = mode_info_seg;
65 regs.eax = 0x4f01;
66 regs.ecx = mode;
67 regs.es = mode_info_seg;
68
69 dpmi_real_int(0x10, &regs);
70 if(regs.eax & 0xff00) {
71 return 0;
72 }
73
74 return mi;
75 }
76
77 int vbe_set_mode(int mode)
78 {
79 struct dpmi_real_regs regs;
80
81 memset(&regs, 0, sizeof regs);
82 regs.eax = 0x4f02;
83 regs.ebx = mode;
84 dpmi_real_int(0x10, &regs);
85
86 if(regs.eax == 0x100) {
87 return -1;
88 }
89 return 0;
90 }
91
92 int vbe_set_palette_bits(int bits)
93 {
94 struct dpmi_real_regs regs;
95
96 memset(&regs, 0, sizeof regs);
97 regs.eax = 0x4f08;
98 regs.ebx = bits << 8; /* bits in bh */
99 dpmi_real_int(0x10, &regs);
100
101 if(((regs.eax >> 8) & 0xff) == 3) {
102 return -1;
103 }
104 return regs.ebx >> 8 & 0xff; /* new color bits in bh */
105 }
106
107 /* TODO: implement palette setting through the VBE2 interface for
108 * non-VGA displays (actually don't).
109 */
110 void vbe_set_palette(int idx, int *col, int count, int bits)
111 {
112 int i, shift = 8 - bits;
113
114 outp(VGA_DAC_ADDR_WR, idx);
115
116 for(i=0; i<count; i++) {
117 unsigned char r = *col++;
118 unsigned char g = *col++;
119 unsigned char b = *col++;
120
121 if(shift) {
122 r >>= shift;
123 g >>= shift;
124 b >>= shift;
125 }
126
127 outp(VGA_DAC_DATA, r);
128 outp(VGA_DAC_DATA, g);
129 outp(VGA_DAC_DATA, b);
130 }
131 }
132
133 int vbe_set_disp_start(int x, int y, int when)
134 {
135 struct dpmi_real_regs regs;
136
137 memset(&regs, 0, sizeof regs);
138 regs.eax = 0x4f07;
139 regs.ebx = when & 0xffff;
140 regs.ecx = x & 0xffff;
141 regs.edx = y & 0xffff;
142 dpmi_real_int(0x10, &regs);
143
144 if(regs.eax == 0x100) {
145 return -1;
146 }
147 return 0;
148 }
149
150 int vbe_set_scanlen(int len, int mode)
151 {
152 struct dpmi_real_regs regs;
153
154 memset(&regs, 0, sizeof regs);
155 regs.eax = 0x4f06;
156 regs.ebx = mode;
157 regs.ecx = len & 0xffff;
158 dpmi_real_int(0x10, &regs);
159
160 if(regs.eax == 0x100) {
161 return -1;
162 }
163 return regs.ecx & 0xffff;
164 }
165
166 int vbe_get_scanlen(int mode)
167 {
168 int res;
169 struct dpmi_real_regs regs;
170
171 memset(&regs, 0, sizeof regs);
172 regs.eax = 0x4f06;
173 regs.ebx = 1;
174 dpmi_real_int(0x10, &regs);
175
176 if(regs.eax == 0x100) {
177 return -1;
178 }
179
180 if(mode == VBE_SCANLEN_PIXELS) {
181 res = regs.ecx & 0xffff;
182 } else {
183 res = regs.ebx & 0xffff;
184 }
185 return res;
186 }
187
188
189 static unsigned int get_mask(int sz, int pos)
190 {
191 unsigned int i, mask = 0;
192
193 for(i=0; i<sz; i++) {
194 mask |= 1 << i;
195 }
196 return mask << pos;
197 }
198
199 void print_mode_info(FILE *fp, struct vbe_mode_info *mi)
200 {
201 fprintf(fp, "resolution: %dx%d\n", mi->xres, mi->yres);
202 fprintf(fp, "color depth: %d\n", mi->bpp);
203 fprintf(fp, "mode attributes: %x\n", mi->mode_attr);
204 fprintf(fp, "bytes per scanline: %d\n", mi->scanline_bytes);
205 fprintf(fp, "number of planes: %d\n", (int)mi->num_planes);
206 fprintf(fp, "number of banks: %d\n", (int)mi->num_banks);
207 fprintf(fp, "mem model: %d\n", (int)mi->mem_model);
208 fprintf(fp, "red bits: %d (mask: %x)\n", (int)mi->rmask_size, get_mask(mi->rmask_size, mi->rpos));
209 fprintf(fp, "green bits: %d (mask: %x)\n", (int)mi->gmask_size, get_mask(mi->gmask_size, mi->gpos));
210 fprintf(fp, "blue bits: %d (mask: %x)\n", (int)mi->bmask_size, get_mask(mi->bmask_size, mi->bpos));
211 fprintf(fp, "framebuffer address: %x\n", (unsigned int)mi->fb_addr);
212 }