1 /*
2 * QEMU EDID generator.
3 *
4 * This work is licensed under the terms of the GNU GPL, version 2 or later.
5 * See the COPYING file in the top-level directory.
6 */
7 #include "qemu/osdep.h"
8 #include "qemu/bswap.h"
9 #include "hw/display/edid.h"
10
11 static const struct edid_mode {
12 uint32_t xres;
13 uint32_t yres;
14 uint32_t byte;
15 uint32_t xtra3;
16 uint32_t bit;
17 uint32_t dta;
18 } modes[] = {
19 /* dea/dta extension timings (all @ 50 Hz) */
20 { .xres = 5120, .yres = 2160, .dta = 125 },
21 { .xres = 4096, .yres = 2160, .dta = 101 },
22 { .xres = 3840, .yres = 2160, .dta = 96 },
23 { .xres = 2560, .yres = 1080, .dta = 89 },
24 { .xres = 2048, .yres = 1152 },
25 { .xres = 1920, .yres = 1080, .dta = 31 },
26
27 /* dea/dta extension timings (all @ 60 Hz) */
28 { .xres = 3840, .yres = 2160, .dta = 97 },
29
30 /* additional standard timings 3 (all @ 60Hz) */
31 { .xres = 1920, .yres = 1200, .xtra3 = 10, .bit = 0 },
32 { .xres = 1600, .yres = 1200, .xtra3 = 9, .bit = 2 },
33 { .xres = 1680, .yres = 1050, .xtra3 = 9, .bit = 5 },
34 { .xres = 1440, .yres = 900, .xtra3 = 8, .bit = 5 },
35 { .xres = 1280, .yres = 1024, .xtra3 = 7, .bit = 1 },
36 { .xres = 1280, .yres = 960, .xtra3 = 7, .bit = 3 },
37 { .xres = 1280, .yres = 768, .xtra3 = 7, .bit = 6 },
38
39 { .xres = 1920, .yres = 1440, .xtra3 = 11, .bit = 5 },
40 { .xres = 1856, .yres = 1392, .xtra3 = 10, .bit = 3 },
41 { .xres = 1792, .yres = 1344, .xtra3 = 10, .bit = 5 },
42 { .xres = 1440, .yres = 1050, .xtra3 = 8, .bit = 1 },
43 { .xres = 1360, .yres = 768, .xtra3 = 8, .bit = 7 },
44
45 /* established timings (all @ 60Hz) */
46 { .xres = 1024, .yres = 768, .byte = 36, .bit = 3 },
47 { .xres = 800, .yres = 600, .byte = 35, .bit = 0 },
48 { .xres = 640, .yres = 480, .byte = 35, .bit = 5 },
49 };
50
51 typedef struct Timings {
52 uint32_t xfront;
53 uint32_t xsync;
54 uint32_t xblank;
55
56 uint32_t yfront;
57 uint32_t ysync;
58 uint32_t yblank;
59
60 uint64_t clock;
61 } Timings;
62
generate_timings(Timings * timings,uint32_t refresh_rate,uint32_t xres,uint32_t yres)63 static void generate_timings(Timings *timings, uint32_t refresh_rate,
64 uint32_t xres, uint32_t yres)
65 {
66 /* pull some realistic looking timings out of thin air */
67 timings->xfront = xres * 25 / 100;
68 timings->xsync = xres * 3 / 100;
69 timings->xblank = xres * 35 / 100;
70
71 timings->yfront = yres * 5 / 1000;
72 timings->ysync = yres * 5 / 1000;
73 timings->yblank = yres * 35 / 1000;
74
75 timings->clock = ((uint64_t)refresh_rate *
76 (xres + timings->xblank) *
77 (yres + timings->yblank)) / 10000000;
78 }
79
edid_ext_dta(uint8_t * dta)80 static void edid_ext_dta(uint8_t *dta)
81 {
82 dta[0] = 0x02;
83 dta[1] = 0x03;
84 dta[2] = 0x05;
85 dta[3] = 0x00;
86
87 /* video data block */
88 dta[4] = 0x40;
89 }
90
edid_ext_dta_mode(uint8_t * dta,uint8_t nr)91 static void edid_ext_dta_mode(uint8_t *dta, uint8_t nr)
92 {
93 dta[dta[2]] = nr;
94 dta[2]++;
95 dta[4]++;
96 }
97
edid_std_mode(uint8_t * mode,uint32_t xres,uint32_t yres)98 static int edid_std_mode(uint8_t *mode, uint32_t xres, uint32_t yres)
99 {
100 uint32_t aspect;
101
102 if (xres == 0 || yres == 0) {
103 mode[0] = 0x01;
104 mode[1] = 0x01;
105 return 0;
106
107 } else if (xres * 10 == yres * 16) {
108 aspect = 0;
109 } else if (xres * 3 == yres * 4) {
110 aspect = 1;
111 } else if (xres * 4 == yres * 5) {
112 aspect = 2;
113 } else if (xres * 9 == yres * 16) {
114 aspect = 3;
115 } else {
116 return -1;
117 }
118
119 if ((xres / 8) - 31 > 255) {
120 return -1;
121 }
122
123 mode[0] = (xres / 8) - 31;
124 mode[1] = ((aspect << 6) | (60 - 60));
125 return 0;
126 }
127
edid_fill_modes(uint8_t * edid,uint8_t * xtra3,uint8_t * dta,uint32_t maxx,uint32_t maxy)128 static void edid_fill_modes(uint8_t *edid, uint8_t *xtra3, uint8_t *dta,
129 uint32_t maxx, uint32_t maxy)
130 {
131 const struct edid_mode *mode;
132 int std = 38;
133 int rc, i;
134
135 for (i = 0; i < ARRAY_SIZE(modes); i++) {
136 mode = modes + i;
137
138 if ((maxx && mode->xres > maxx) ||
139 (maxy && mode->yres > maxy)) {
140 continue;
141 }
142
143 if (mode->byte) {
144 edid[mode->byte] |= (1 << mode->bit);
145 } else if (std < 54) {
146 rc = edid_std_mode(edid + std, mode->xres, mode->yres);
147 if (rc == 0) {
148 std += 2;
149 }
150 } else if (mode->xtra3 && xtra3) {
151 xtra3[mode->xtra3] |= (1 << mode->bit);
152 }
153
154 if (dta && mode->dta) {
155 edid_ext_dta_mode(dta, mode->dta);
156 }
157 }
158
159 while (std < 54) {
160 edid_std_mode(edid + std, 0, 0);
161 std += 2;
162 }
163 }
164
edid_checksum(uint8_t * edid,size_t len)165 static void edid_checksum(uint8_t *edid, size_t len)
166 {
167 uint32_t sum = 0;
168 int i;
169
170 for (i = 0; i < len; i++) {
171 sum += edid[i];
172 }
173 sum &= 0xff;
174 if (sum) {
175 edid[len] = 0x100 - sum;
176 }
177 }
178
edid_desc_next(uint8_t * edid,uint8_t * dta,uint8_t * desc)179 static uint8_t *edid_desc_next(uint8_t *edid, uint8_t *dta, uint8_t *desc)
180 {
181 if (desc == NULL) {
182 return NULL;
183 }
184 if (desc + 18 + 18 < edid + 127) {
185 return desc + 18;
186 }
187 if (dta) {
188 if (desc < edid + 127) {
189 return dta + dta[2];
190 }
191 if (desc + 18 + 18 < dta + 127) {
192 return desc + 18;
193 }
194 }
195 return NULL;
196 }
197
edid_desc_type(uint8_t * desc,uint8_t type)198 static void edid_desc_type(uint8_t *desc, uint8_t type)
199 {
200 desc[0] = 0;
201 desc[1] = 0;
202 desc[2] = 0;
203 desc[3] = type;
204 desc[4] = 0;
205 }
206
edid_desc_text(uint8_t * desc,uint8_t type,const char * text)207 static void edid_desc_text(uint8_t *desc, uint8_t type,
208 const char *text)
209 {
210 size_t len;
211
212 edid_desc_type(desc, type);
213 memset(desc + 5, ' ', 13);
214
215 len = strlen(text);
216 if (len > 12) {
217 len = 12;
218 }
219 memcpy(desc + 5, text, len);
220 desc[5 + len] = '\n';
221 }
222
edid_desc_ranges(uint8_t * desc)223 static void edid_desc_ranges(uint8_t *desc)
224 {
225 edid_desc_type(desc, 0xfd);
226
227 /* vertical (50 -> 125 Hz) */
228 desc[5] = 50;
229 desc[6] = 125;
230
231 /* horizontal (30 -> 160 kHz) */
232 desc[7] = 30;
233 desc[8] = 160;
234
235 /* max dot clock (2550 MHz) */
236 desc[9] = 2550 / 10;
237
238 /* no extended timing information */
239 desc[10] = 0x01;
240
241 /* padding */
242 desc[11] = '\n';
243 memset(desc + 12, ' ', 6);
244 }
245
246 /* additional standard timings 3 */
edid_desc_xtra3_std(uint8_t * desc)247 static void edid_desc_xtra3_std(uint8_t *desc)
248 {
249 edid_desc_type(desc, 0xf7);
250 desc[5] = 10;
251 }
252
edid_desc_dummy(uint8_t * desc)253 static void edid_desc_dummy(uint8_t *desc)
254 {
255 edid_desc_type(desc, 0x10);
256 }
257
edid_desc_timing(uint8_t * desc,const Timings * timings,uint32_t xres,uint32_t yres,uint32_t xmm,uint32_t ymm)258 static void edid_desc_timing(uint8_t *desc, const Timings *timings,
259 uint32_t xres, uint32_t yres,
260 uint32_t xmm, uint32_t ymm)
261 {
262 stw_le_p(desc, timings->clock);
263
264 desc[2] = xres & 0xff;
265 desc[3] = timings->xblank & 0xff;
266 desc[4] = (((xres & 0xf00) >> 4) |
267 ((timings->xblank & 0xf00) >> 8));
268
269 desc[5] = yres & 0xff;
270 desc[6] = timings->yblank & 0xff;
271 desc[7] = (((yres & 0xf00) >> 4) |
272 ((timings->yblank & 0xf00) >> 8));
273
274 desc[8] = timings->xfront & 0xff;
275 desc[9] = timings->xsync & 0xff;
276
277 desc[10] = (((timings->yfront & 0x00f) << 4) |
278 ((timings->ysync & 0x00f) << 0));
279 desc[11] = (((timings->xfront & 0x300) >> 2) |
280 ((timings->xsync & 0x300) >> 4) |
281 ((timings->yfront & 0x030) >> 2) |
282 ((timings->ysync & 0x030) >> 4));
283
284 desc[12] = xmm & 0xff;
285 desc[13] = ymm & 0xff;
286 desc[14] = (((xmm & 0xf00) >> 4) |
287 ((ymm & 0xf00) >> 8));
288
289 desc[17] = 0x18;
290 }
291
edid_to_10bit(float value)292 static uint32_t edid_to_10bit(float value)
293 {
294 return (uint32_t)(value * 1024 + 0.5);
295 }
296
edid_colorspace(uint8_t * edid,float rx,float ry,float gx,float gy,float bx,float by,float wx,float wy)297 static void edid_colorspace(uint8_t *edid,
298 float rx, float ry,
299 float gx, float gy,
300 float bx, float by,
301 float wx, float wy)
302 {
303 uint32_t red_x = edid_to_10bit(rx);
304 uint32_t red_y = edid_to_10bit(ry);
305 uint32_t green_x = edid_to_10bit(gx);
306 uint32_t green_y = edid_to_10bit(gy);
307 uint32_t blue_x = edid_to_10bit(bx);
308 uint32_t blue_y = edid_to_10bit(by);
309 uint32_t white_x = edid_to_10bit(wx);
310 uint32_t white_y = edid_to_10bit(wy);
311
312 edid[25] = (((red_x & 0x03) << 6) |
313 ((red_y & 0x03) << 4) |
314 ((green_x & 0x03) << 2) |
315 ((green_y & 0x03) << 0));
316 edid[26] = (((blue_x & 0x03) << 6) |
317 ((blue_y & 0x03) << 4) |
318 ((white_x & 0x03) << 2) |
319 ((white_y & 0x03) << 0));
320 edid[27] = red_x >> 2;
321 edid[28] = red_y >> 2;
322 edid[29] = green_x >> 2;
323 edid[30] = green_y >> 2;
324 edid[31] = blue_x >> 2;
325 edid[32] = blue_y >> 2;
326 edid[33] = white_x >> 2;
327 edid[34] = white_y >> 2;
328 }
329
qemu_edid_dpi_from_mm(uint32_t mm,uint32_t res)330 static uint32_t qemu_edid_dpi_from_mm(uint32_t mm, uint32_t res)
331 {
332 return res * 254 / 10 / mm;
333 }
334
qemu_edid_dpi_to_mm(uint32_t dpi,uint32_t res)335 uint32_t qemu_edid_dpi_to_mm(uint32_t dpi, uint32_t res)
336 {
337 return res * 254 / 10 / dpi;
338 }
339
init_displayid(uint8_t * did)340 static void init_displayid(uint8_t *did)
341 {
342 did[0] = 0x70; /* display id extension */
343 did[1] = 0x13; /* version 1.3 */
344 did[2] = 4; /* length */
345 did[3] = 0x03; /* product type (0x03 == standalone display device) */
346 edid_checksum(did + 1, did[2] + 4);
347 }
348
qemu_displayid_generate(uint8_t * did,const Timings * timings,uint32_t xres,uint32_t yres,uint32_t xmm,uint32_t ymm)349 static void qemu_displayid_generate(uint8_t *did, const Timings *timings,
350 uint32_t xres, uint32_t yres,
351 uint32_t xmm, uint32_t ymm)
352 {
353 did[0] = 0x70; /* display id extension */
354 did[1] = 0x13; /* version 1.3 */
355 did[2] = 23; /* length */
356 did[3] = 0x03; /* product type (0x03 == standalone display device) */
357
358 did[5] = 0x03; /* Detailed Timings Data Block */
359 did[6] = 0x00; /* revision */
360 did[7] = 0x14; /* block length */
361
362 did[8] = timings->clock & 0xff;
363 did[9] = (timings->clock & 0xff00) >> 8;
364 did[10] = (timings->clock & 0xff0000) >> 16;
365
366 did[11] = 0x88; /* leave aspect ratio undefined */
367
368 stw_le_p(did + 12, 0xffff & (xres - 1));
369 stw_le_p(did + 14, 0xffff & (timings->xblank - 1));
370 stw_le_p(did + 16, 0xffff & (timings->xfront - 1));
371 stw_le_p(did + 18, 0xffff & (timings->xsync - 1));
372
373 stw_le_p(did + 20, 0xffff & (yres - 1));
374 stw_le_p(did + 22, 0xffff & (timings->yblank - 1));
375 stw_le_p(did + 24, 0xffff & (timings->yfront - 1));
376 stw_le_p(did + 26, 0xffff & (timings->ysync - 1));
377
378 edid_checksum(did + 1, did[2] + 4);
379 }
380
qemu_edid_generate(uint8_t * edid,size_t size,qemu_edid_info * info)381 void qemu_edid_generate(uint8_t *edid, size_t size,
382 qemu_edid_info *info)
383 {
384 Timings timings;
385 uint8_t *desc = edid + 54;
386 uint8_t *xtra3 = NULL;
387 uint8_t *dta = NULL;
388 uint8_t *did = NULL;
389 uint32_t width_mm, height_mm;
390 uint32_t refresh_rate = info->refresh_rate ? info->refresh_rate : 75000;
391 uint32_t dpi = 100; /* if no width_mm/height_mm */
392 uint32_t large_screen = 0;
393
394 /* =============== set defaults =============== */
395
396 if (!info->vendor || strlen(info->vendor) != 3) {
397 info->vendor = "RHT";
398 }
399 if (!info->name) {
400 info->name = "QEMU Monitor";
401 }
402 if (!info->prefx) {
403 info->prefx = 1280;
404 }
405 if (!info->prefy) {
406 info->prefy = 800;
407 }
408 if (info->width_mm && info->height_mm) {
409 width_mm = info->width_mm;
410 height_mm = info->height_mm;
411 dpi = qemu_edid_dpi_from_mm(width_mm, info->prefx);
412 } else {
413 width_mm = qemu_edid_dpi_to_mm(dpi, info->prefx);
414 height_mm = qemu_edid_dpi_to_mm(dpi, info->prefy);
415 }
416
417 generate_timings(&timings, refresh_rate, info->prefx, info->prefy);
418 if (info->prefx >= 4096 || info->prefy >= 4096 || timings.clock >= 65536) {
419 large_screen = 1;
420 }
421
422 /* =============== extensions =============== */
423
424 if (size >= 256) {
425 dta = edid + 128;
426 edid[126]++;
427 edid_ext_dta(dta);
428 }
429
430 if (size >= 384 && large_screen) {
431 did = edid + 256;
432 edid[126]++;
433 init_displayid(did);
434 }
435
436 /* =============== header information =============== */
437
438 /* fixed */
439 edid[0] = 0x00;
440 edid[1] = 0xff;
441 edid[2] = 0xff;
442 edid[3] = 0xff;
443 edid[4] = 0xff;
444 edid[5] = 0xff;
445 edid[6] = 0xff;
446 edid[7] = 0x00;
447
448 /* manufacturer id, product code, serial number */
449 uint16_t vendor_id = ((((info->vendor[0] - '@') & 0x1f) << 10) |
450 (((info->vendor[1] - '@') & 0x1f) << 5) |
451 (((info->vendor[2] - '@') & 0x1f) << 0));
452 uint16_t model_nr = 0x1234;
453 uint32_t serial_nr = info->serial ? atoi(info->serial) : 0;
454 stw_be_p(edid + 8, vendor_id);
455 stw_le_p(edid + 10, model_nr);
456 stl_le_p(edid + 12, serial_nr);
457
458 /* manufacture week and year */
459 edid[16] = 42;
460 edid[17] = 2014 - 1990;
461
462 /* edid version */
463 edid[18] = 1;
464 edid[19] = 4;
465
466
467 /* =============== basic display parameters =============== */
468
469 /* video input: digital, 8bpc, displayport */
470 edid[20] = 0xa5;
471
472 /* screen size: undefined */
473 edid[21] = width_mm / 10;
474 edid[22] = height_mm / 10;
475
476 /* display gamma: 2.2 */
477 edid[23] = 220 - 100;
478
479 /* supported features bitmap: std sRGB, preferred timing */
480 edid[24] = 0x06;
481
482
483 /* =============== chromaticity coordinates =============== */
484
485 /* standard sRGB colorspace */
486 edid_colorspace(edid,
487 0.6400, 0.3300, /* red */
488 0.3000, 0.6000, /* green */
489 0.1500, 0.0600, /* blue */
490 0.3127, 0.3290); /* white point */
491
492 /* =============== established timing bitmap =============== */
493 /* =============== standard timing information =============== */
494
495 /* both filled by edid_fill_modes() */
496
497
498 /* =============== descriptor blocks =============== */
499
500 if (!large_screen) {
501 /* The DTD section has only 12 bits to store the resolution */
502 edid_desc_timing(desc, &timings, info->prefx, info->prefy,
503 width_mm, height_mm);
504 desc = edid_desc_next(edid, dta, desc);
505 }
506
507 xtra3 = desc;
508 edid_desc_xtra3_std(xtra3);
509 desc = edid_desc_next(edid, dta, desc);
510 edid_fill_modes(edid, xtra3, dta, info->maxx, info->maxy);
511 /*
512 * dta video data block is finished at thus point,
513 * so dta descriptor offsets don't move any more.
514 */
515
516 edid_desc_ranges(desc);
517 desc = edid_desc_next(edid, dta, desc);
518
519 if (desc && info->name) {
520 edid_desc_text(desc, 0xfc, info->name);
521 desc = edid_desc_next(edid, dta, desc);
522 }
523
524 if (desc && info->serial) {
525 edid_desc_text(desc, 0xff, info->serial);
526 desc = edid_desc_next(edid, dta, desc);
527 }
528
529 while (desc) {
530 edid_desc_dummy(desc);
531 desc = edid_desc_next(edid, dta, desc);
532 }
533
534 /* =============== display id extensions =============== */
535
536 if (did && large_screen) {
537 qemu_displayid_generate(did, &timings, info->prefx, info->prefy,
538 width_mm, height_mm);
539 }
540
541 /* =============== finish up =============== */
542
543 edid_checksum(edid, 127);
544 if (dta) {
545 edid_checksum(dta, 127);
546 }
547 if (did) {
548 edid_checksum(did, 127);
549 }
550 }
551
qemu_edid_size(uint8_t * edid)552 size_t qemu_edid_size(uint8_t *edid)
553 {
554 uint32_t exts;
555
556 if (edid[0] != 0x00 ||
557 edid[1] != 0xff) {
558 /* doesn't look like a valid edid block */
559 return 0;
560 }
561
562 exts = edid[126];
563 return 128 * (exts + 1);
564 }
565