1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2
3 #include <pc80/vga.h>
4 #include <pc80/vga_io.h>
5
6 #include <string.h>
7 #include "vga.h"
8
9 /*
10 * pci io enable should've happened before
11 */
12 void
vga_io_init(void)13 vga_io_init(void)
14 {
15 vga_enable_mask(0x01, 0x01);
16
17 /* cr io is at 0x3D4/0x3D5 */
18 vga_misc_mask(0x01, 0x01);
19
20 /* clear cr0-7 protection */
21 vga_cr_mask(0x11, 0x00, 0x80);
22 }
23
24 /*
25 *
26 */
27 static void
vga_fb_init(void)28 vga_fb_init(void)
29 {
30 vga_sr_write(0x02, 0x03);
31 vga_sr_write(0x03, 0x00);
32 vga_sr_write(0x04, 0x02); /* access all 256kB */
33
34 vga_gr_write(0x00, 0x00);
35 vga_gr_write(0x01, 0x00);
36 vga_gr_write(0x02, 0x00);
37 vga_gr_write(0x03, 0x00);
38 vga_gr_write(0x04, 0x00);
39 vga_gr_write(0x05, 0x10);
40 vga_gr_write(0x06, 0x0E); /* map at 0xB8000 */
41 vga_gr_write(0x07, 0x00);
42 vga_gr_write(0x08, 0xFF);
43
44 /* o/e enable: RAM enable */
45 vga_misc_mask(0x22, 0x22);
46 }
47
48 /*
49 *
50 */
51 static void
vga_fb_clear(void)52 vga_fb_clear(void)
53 {
54 memset((void *)VGA_FB, 0x00, 0x8000);
55 }
56
57 /*
58 *
59 */
60 static void
vga_palette_init(void)61 vga_palette_init(void)
62 {
63 size_t i;
64
65 /* set up attribute registers */
66 for (i = 0; i < 0x10; i++)
67 vga_ar_write(i, i);
68
69 vga_ar_write(0x10, 0x0c);
70 vga_ar_write(0x11, 0x00);
71 vga_ar_write(0x12, 0x0F);
72 vga_ar_write(0x13, 0x08);
73 vga_ar_write(0x14, 0x00);
74
75 vga_palette_disable();
76
77 /* load actual palette */
78 vga_dac_mask_write(0xFF);
79
80 for (i = 0; i < 0x100; i++) {
81 vga_dac_write_address(i);
82 vga_dac_data_write(default_vga_palette[i].red);
83 vga_dac_data_write(default_vga_palette[i].green);
84 vga_dac_data_write(default_vga_palette[i].blue);
85 }
86 }
87
88 /*
89 *
90 */
91 static void
vga_mode_set(int hdisplay,int hblankstart,int hsyncstart,int hsyncend,int hblankend,int htotal,int vdisplay,int vblankstart,int vsyncstart,int vsyncend,int vblankend,int vtotal,int stride)92 vga_mode_set(int hdisplay, int hblankstart, int hsyncstart, int hsyncend,
93 int hblankend, int htotal, int vdisplay, int vblankstart,
94 int vsyncstart, int vsyncend, int vblankend, int vtotal,
95 int stride)
96 {
97 /* htotal: 2080 */
98 htotal /= 8;
99 htotal -= 5;
100 vga_cr_write(0x00, htotal);
101
102 /* hdisplay: 2048 */
103 hdisplay /= 8;
104 hdisplay -= 1;
105 vga_cr_write(0x01, hdisplay);
106
107 /* hblankstart: 2048 */
108 hblankstart /= 8;
109 hblankstart -= 1;
110 vga_cr_write(0x02, hblankstart);
111
112 /* hblankend: hblankstart + 512 */
113 hblankend /= 8;
114 hblankend -= 1;
115 vga_cr_mask(0x03, hblankend, 0x1F);
116 vga_cr_mask(0x05, hblankend << 2, 0x80);
117
118 /* hsyncstart: 255 * 8: 2040 */
119 vga_cr_write(0x04, hsyncstart / 8);
120
121 /* hsyncend: hsyncstart + 255 */
122 vga_cr_mask(0x05, hsyncend / 8, 0x1F);
123
124 /* vtotal: 1025 */
125 vtotal -= 2;
126 vga_cr_write(0x06, vtotal);
127 vga_cr_mask(0x07, vtotal >> 8, 0x01);
128 vga_cr_mask(0x07, vtotal >> 4, 0x20);
129
130 /* vdisplay: 1024 */
131 vdisplay -= 1;
132 vga_cr_write(0x12, vdisplay);
133 vga_cr_mask(0x07, vdisplay >> 7, 0x02);
134 vga_cr_mask(0x07, vdisplay >> 3, 0x40);
135
136 /* vblankstart: 1024 */
137 vblankstart -= 1;
138 vga_cr_write(0x15, vblankstart);
139 vga_cr_mask(0x07, vblankstart >> 5, 0x08);
140 vga_cr_mask(0x09, vblankstart >> 4, 0x20);
141
142 /* vblankend: vblankstart + 256 */
143 vblankend -= 1;
144 vga_cr_write(0x16, vblankend);
145
146 /* vsyncstart: 1023 */
147 vga_cr_write(0x10, vsyncstart);
148 vga_cr_mask(0x07, vsyncstart >> 6, 0x04);
149 vga_cr_mask(0x07, vsyncstart >> 2, 0x80);
150
151 /* vsyncend: vsyncstart + 16 */
152 vga_cr_mask(0x11, vsyncend, 0x0F);
153
154 /* stride */
155 vga_cr_write(0x13, stride / 8);
156
157 /* line compare */
158 vga_cr_write(0x18, 0xFF);
159 vga_cr_mask(0x07, 0x10, 0x10);
160 vga_cr_mask(0x09, 0x40, 0x40);
161
162 vga_misc_mask(0x44, 0xCC); /* set up clock: 27mhz and h/vsync */
163
164 vga_cr_mask(0x09, 0x00, 0x80); /* disable doublescan */
165 }
166
167 static void
vga_font_8x16_load(void)168 vga_font_8x16_load(void)
169 {
170 unsigned char *p;
171 size_t i, j;
172 unsigned char sr2, sr4, gr5, gr6;
173
174 #define height 16
175 #define count 256
176
177 sr2 = vga_sr_read(0x02);
178 sr4 = vga_sr_read(0x04);
179 gr5 = vga_gr_read(0x05);
180 gr6 = vga_gr_read(0x06);
181
182 /* disable odd/even */
183 vga_sr_mask(0x04, 0x04, 0x04);
184 vga_gr_mask(0x05, 0x00, 0x10);
185 vga_gr_mask(0x06, 0x00, 0x02);
186
187 /* plane 2 */
188 vga_sr_write(0x02, 0x04);
189 p = (unsigned char *)VGA_FB;
190 for (i = 0; i < count; i++) {
191 for (j = 0; j < 32; j++) {
192 if (j < height)
193 *p = vga_font_8x16[i][j];
194 else
195 *p = 0x00;
196 p++;
197 }
198 }
199
200 vga_gr_write(0x06, gr6);
201 vga_gr_write(0x05, gr5);
202 vga_sr_write(0x04, sr4);
203 vga_sr_write(0x02, sr2);
204
205 /* set up font size */
206 vga_cr_mask(0x09, 16 - 1, 0x1F);
207 }
208
209 /*
210 *
211 */
212 void
vga_cursor_enable(int enable)213 vga_cursor_enable(int enable)
214 {
215 if (enable)
216 vga_cr_mask(0x0A, 0x00, 0x20);
217 else
218 vga_cr_mask(0x0A, 0x20, 0x20);
219 }
220
221 /*
222 *
223 */
224 void
vga_cursor_reset(void)225 vga_cursor_reset(void)
226 {
227 vga_cr_write(0x0A, 0x2E);
228 vga_cr_write(0x0B, 0x0E);
229 vga_cr_write(0x0E, 0x00);
230 vga_cr_write(0x0F, 0x00);
231 }
232
233 /*
234 *
235 */
236 void
vga_cursor_set(unsigned int line,unsigned int character)237 vga_cursor_set(unsigned int line, unsigned int character)
238 {
239 unsigned int offset = (VGA_COLUMNS * line + character) & 0xFFFF;
240
241 vga_cr_write(0x0A, 0x0E);
242 vga_cr_write(0x0B, 0x0E);
243 vga_cr_write(0x0E, offset >> 8);
244 vga_cr_write(0x0F, offset & 0xFF);
245 }
246
247 /*
248 *
249 */
250 void
vga_frame_set(unsigned int line,unsigned int character)251 vga_frame_set(unsigned int line, unsigned int character)
252 {
253 unsigned int offset = (VGA_COLUMNS * line + character) & 0xFFFF;
254
255 vga_cr_write(0x0C, offset >> 8);
256 vga_cr_write(0x0D, offset & 0xFF);
257 }
258
259 static void
vga_write_at_offset(unsigned int line,unsigned int offset,const char * string)260 vga_write_at_offset(unsigned int line, unsigned int offset, const char *string)
261 {
262 if (!string)
263 return;
264
265 unsigned short *p = (unsigned short *)VGA_FB + (VGA_COLUMNS * line) + offset;
266 size_t i, len = strlen(string);
267
268 for (i = 0; i < (VGA_COLUMNS - offset); i++) {
269 if (i < len)
270 p[i] = 0x0F00 | (unsigned char)string[i];
271 else
272 p[i] = 0x0F00;
273 }
274 }
275
276 /*
277 * simply fills a line with the given string.
278 */
279 void
vga_line_write(unsigned int line,const char * string)280 vga_line_write(unsigned int line, const char *string)
281 {
282 vga_write_at_offset(line, 0, string);
283 }
284
285 void
vga_write_text(enum VGA_TEXT_ALIGNMENT alignment,unsigned int line,const unsigned char * ustring)286 vga_write_text(enum VGA_TEXT_ALIGNMENT alignment, unsigned int line,
287 const unsigned char *ustring)
288 {
289 const char *string = (const char *)ustring;
290 char str[VGA_COLUMNS * VGA_LINES] = {0};
291 memcpy(str, string, strnlen(string, sizeof(str) - 1));
292
293 char *token = strtok(str, "\n");
294
295 while (token != NULL) {
296 size_t offset = VGA_COLUMNS - strnlen(token, VGA_COLUMNS);
297 switch (alignment) {
298 case VGA_TEXT_CENTER:
299 vga_write_at_offset(line++, offset/2, token);
300 break;
301 case VGA_TEXT_RIGHT:
302 vga_write_at_offset(line++, offset, token);
303 break;
304 case VGA_TEXT_LEFT:
305 default:
306 vga_write_at_offset(line++, 0, token);
307 break;
308 }
309 token = strtok(NULL, "\n");
310 }
311 }
312
313 /*
314 * set up everything to get a basic 80x25 textmode.
315 */
316 void
vga_textmode_init(void)317 vga_textmode_init(void)
318 {
319 vga_sr_write(0x00, 0x01); /* clear reset */
320 vga_sr_write(0x01, 0x00);
321
322 /* set up cr */
323 vga_cr_mask(0x03, 0x80, 0xE0);
324 vga_cr_mask(0x05, 0x00, 0x60);
325
326 vga_cr_write(0x08, 0x00);
327
328 vga_cr_write(0x14, 0x00); /* */
329
330 vga_cr_write(0x17, 0x23);
331
332 vga_palette_init();
333
334 vga_mode_set(640, 648, 680, 776, 792, 800,
335 400, 407, 412, 414, 442, 449, 320);
336
337 vga_cursor_reset();
338 vga_frame_set(0, 0);
339
340 vga_fb_init();
341 vga_fb_clear();
342 vga_font_8x16_load();
343
344 vga_sr_mask(0x00, 0x02, 0x02); /* take us out of reset */
345 vga_cr_mask(0x17, 0x80, 0x80); /* sync! */
346 }
347