1 /* vi: set sw=4 ts=4: */
2 /*
3 * Mini fbset implementation for busybox
4 *
5 * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 *
9 * This is a from-scratch implementation of fbset; but the de facto fbset
10 * implementation was a good reference. fbset (original) is released under
11 * the GPL, and is (c) 1995-1999 by:
12 * Geert Uytterhoeven (Geert.Uytterhoeven@cs.kuleuven.ac.be)
13 */
14 //config:config FBSET
15 //config: bool "fbset (5.9 kb)"
16 //config: default y
17 //config: help
18 //config: fbset is used to show or change the settings of a Linux frame buffer
19 //config: device. The frame buffer device provides a simple and unique
20 //config: interface to access a graphics display. Enable this option
21 //config: if you wish to enable the 'fbset' utility.
22 //config:
23 //config:config FEATURE_FBSET_FANCY
24 //config: bool "Enable extra options"
25 //config: default y
26 //config: depends on FBSET
27 //config: help
28 //config: This option enables extended fbset options, allowing one to set the
29 //config: framebuffer size, color depth, etc. interface to access a graphics
30 //config: display. Enable this option if you wish to enable extended fbset
31 //config: options.
32 //config:
33 //config:config FEATURE_FBSET_READMODE
34 //config: bool "Enable readmode support"
35 //config: default y
36 //config: depends on FBSET
37 //config: help
38 //config: This option allows fbset to read the video mode database stored by
39 //config: default as /etc/fb.modes, which can be used to set frame buffer
40 //config: device to pre-defined video modes.
41
42 //applet:IF_FBSET(APPLET(fbset, BB_DIR_USR_SBIN, BB_SUID_DROP))
43
44 //kbuild:lib-$(CONFIG_FBSET) += fbset.o
45
46 //usage:#define fbset_trivial_usage
47 //usage: "[OPTIONS] [MODE]"
48 //usage:#define fbset_full_usage "\n\n"
49 //usage: "Show and modify frame buffer settings"
50 //usage:
51 //usage:#define fbset_example_usage
52 //usage: "$ fbset\n"
53 //usage: "mode \"1024x768-76\"\n"
54 //usage: " # D: 78.653 MHz, H: 59.949 kHz, V: 75.694 Hz\n"
55 //usage: " geometry 1024 768 1024 768 16\n"
56 //usage: " timings 12714 128 32 16 4 128 4\n"
57 //usage: " accel false\n"
58 //usage: " rgba 5/11,6/5,5/0,0/0\n"
59 //usage: "endmode\n"
60
61 #include "libbb.h"
62
63 #define DEFAULTFBDEV FB_0
64 #define DEFAULTFBMODE "/etc/fb.modes"
65
66 /* Stuff stolen from the kernel's fb.h */
67 #define FB_ACTIVATE_ALL 64
68 enum {
69 FBIOGET_VSCREENINFO = 0x4600,
70 FBIOPUT_VSCREENINFO = 0x4601
71 };
72
73 struct fb_bitfield {
74 uint32_t offset; /* beginning of bitfield */
75 uint32_t length; /* length of bitfield */
76 uint32_t msb_right; /* !=0: Most significant bit is right */
77 };
78 struct fb_var_screeninfo {
79 uint32_t xres; /* visible resolution */
80 uint32_t yres;
81 uint32_t xres_virtual; /* virtual resolution */
82 uint32_t yres_virtual;
83 uint32_t xoffset; /* offset from virtual to visible */
84 uint32_t yoffset; /* resolution */
85
86 uint32_t bits_per_pixel;
87 uint32_t grayscale; /* !=0 Graylevels instead of colors */
88
89 struct fb_bitfield red; /* bitfield in fb mem if true color, */
90 struct fb_bitfield green; /* else only length is significant */
91 struct fb_bitfield blue;
92 struct fb_bitfield transp; /* transparency */
93
94 uint32_t nonstd; /* !=0 Non standard pixel format */
95
96 uint32_t activate; /* see FB_ACTIVATE_x */
97
98 uint32_t height; /* height of picture in mm */
99 uint32_t width; /* width of picture in mm */
100
101 uint32_t accel_flags; /* acceleration flags (hints) */
102
103 /* Timing: All values in pixclocks, except pixclock (of course) */
104 uint32_t pixclock; /* pixel clock in ps (pico seconds) */
105 uint32_t left_margin; /* time from sync to picture */
106 uint32_t right_margin; /* time from picture to sync */
107 uint32_t upper_margin; /* time from sync to picture */
108 uint32_t lower_margin;
109 uint32_t hsync_len; /* length of horizontal sync */
110 uint32_t vsync_len; /* length of vertical sync */
111 uint32_t sync; /* see FB_SYNC_x */
112 uint32_t vmode; /* see FB_VMODE_x */
113 uint32_t reserved[6]; /* Reserved for future compatibility */
114 };
115
copy_if_gt0(uint32_t * src,uint32_t * dst,unsigned cnt)116 static void copy_if_gt0(uint32_t *src, uint32_t *dst, unsigned cnt)
117 {
118 do {
119 if ((int32_t) *src > 0)
120 *dst = *src;
121 src++;
122 dst++;
123 } while (--cnt);
124 }
125
copy_changed_values(struct fb_var_screeninfo * base,struct fb_var_screeninfo * set)126 static NOINLINE void copy_changed_values(
127 struct fb_var_screeninfo *base,
128 struct fb_var_screeninfo *set)
129 {
130 //if ((int32_t) set->xres > 0) base->xres = set->xres;
131 //if ((int32_t) set->yres > 0) base->yres = set->yres;
132 //if ((int32_t) set->xres_virtual > 0) base->xres_virtual = set->xres_virtual;
133 //if ((int32_t) set->yres_virtual > 0) base->yres_virtual = set->yres_virtual;
134 copy_if_gt0(&set->xres, &base->xres, 4);
135
136 if ((int32_t) set->bits_per_pixel > 0) base->bits_per_pixel = set->bits_per_pixel;
137 //copy_if_gt0(&set->bits_per_pixel, &base->bits_per_pixel, 1);
138
139 //if ((int32_t) set->pixclock > 0) base->pixclock = set->pixclock;
140 //if ((int32_t) set->left_margin > 0) base->left_margin = set->left_margin;
141 //if ((int32_t) set->right_margin > 0) base->right_margin = set->right_margin;
142 //if ((int32_t) set->upper_margin > 0) base->upper_margin = set->upper_margin;
143 //if ((int32_t) set->lower_margin > 0) base->lower_margin = set->lower_margin;
144 //if ((int32_t) set->hsync_len > 0) base->hsync_len = set->hsync_len;
145 //if ((int32_t) set->vsync_len > 0) base->vsync_len = set->vsync_len;
146 //if ((int32_t) set->sync > 0) base->sync = set->sync;
147 //if ((int32_t) set->vmode > 0) base->vmode = set->vmode;
148 copy_if_gt0(&set->pixclock, &base->pixclock, 9);
149 }
150
151
152 enum {
153 CMD_FB = 1,
154 CMD_DB = 2,
155 CMD_GEOMETRY = 3,
156 CMD_TIMING = 4,
157 CMD_ACCEL = 5,
158 CMD_HSYNC = 6,
159 CMD_VSYNC = 7,
160 CMD_LACED = 8,
161 CMD_DOUBLE = 9,
162 /* CMD_XCOMPAT = 10, */
163 CMD_ALL = 11,
164 CMD_INFO = 12,
165 CMD_SHOW = 13,
166 CMD_CHANGE = 14,
167
168 #if ENABLE_FEATURE_FBSET_FANCY
169 CMD_XRES = 100,
170 CMD_YRES = 101,
171 CMD_VXRES = 102,
172 CMD_VYRES = 103,
173 CMD_DEPTH = 104,
174 CMD_MATCH = 105,
175 CMD_PIXCLOCK = 106,
176 CMD_LEFT = 107,
177 CMD_RIGHT = 108,
178 CMD_UPPER = 109,
179 CMD_LOWER = 110,
180 CMD_HSLEN = 111,
181 CMD_VSLEN = 112,
182 CMD_CSYNC = 113,
183 CMD_GSYNC = 114,
184 CMD_EXTSYNC = 115,
185 CMD_BCAST = 116,
186 CMD_RGBA = 117,
187 CMD_STEP = 118,
188 CMD_MOVE = 119,
189 #endif
190 };
191
192 static const struct cmdoptions_t {
193 const char name[9];
194 const unsigned char param_count;
195 const unsigned char code;
196 } g_cmdoptions[] ALIGN1 = {
197 /*"12345678" + NUL */
198 //TODO: convert to index_in_strings()
199 { "fb" , 1, CMD_FB },
200 { "db" , 1, CMD_DB },
201 { "a" , 0, CMD_ALL },
202 { "i" , 0, CMD_INFO },
203 { "g" , 5, CMD_GEOMETRY },
204 { "t" , 7, CMD_TIMING },
205 { "accel" , 1, CMD_ACCEL },
206 { "hsync" , 1, CMD_HSYNC },
207 { "vsync" , 1, CMD_VSYNC },
208 { "laced" , 1, CMD_LACED },
209 { "double" , 1, CMD_DOUBLE },
210 { "show" , 0, CMD_SHOW },
211 { "s" , 0, CMD_SHOW },
212 #if ENABLE_FEATURE_FBSET_FANCY
213 { "all" , 0, CMD_ALL },
214 { "xres" , 1, CMD_XRES },
215 { "yres" , 1, CMD_YRES },
216 { "vxres" , 1, CMD_VXRES },
217 { "vyres" , 1, CMD_VYRES },
218 { "depth" , 1, CMD_DEPTH },
219 { "match" , 0, CMD_MATCH },
220 { "geometry", 5, CMD_GEOMETRY },
221 { "pixclock", 1, CMD_PIXCLOCK },
222 { "left" , 1, CMD_LEFT },
223 { "right" , 1, CMD_RIGHT },
224 { "upper" , 1, CMD_UPPER },
225 { "lower" , 1, CMD_LOWER },
226 { "hslen" , 1, CMD_HSLEN },
227 { "vslen" , 1, CMD_VSLEN },
228 { "timings" , 7, CMD_TIMING },
229 { "csync" , 1, CMD_CSYNC },
230 { "gsync" , 1, CMD_GSYNC },
231 { "extsync" , 1, CMD_EXTSYNC },
232 { "bcast" , 1, CMD_BCAST },
233 { "rgba" , 1, CMD_RGBA },
234 { "step" , 1, CMD_STEP },
235 { "move" , 1, CMD_MOVE },
236 #endif
237 };
238
239 /* taken from linux/fb.h */
240 enum {
241 FB_SYNC_HOR_HIGH_ACT = 1, /* horizontal sync high active */
242 FB_SYNC_VERT_HIGH_ACT = 2, /* vertical sync high active */
243 #if ENABLE_FEATURE_FBSET_READMODE
244 FB_VMODE_INTERLACED = 1, /* interlaced */
245 FB_VMODE_DOUBLE = 2, /* double scan */
246 FB_SYNC_EXT = 4, /* external sync */
247 FB_SYNC_COMP_HIGH_ACT = 8, /* composite sync high active */
248 #endif
249 };
250
251 #if ENABLE_FEATURE_FBSET_READMODE
ss(uint32_t * x,uint32_t flag,char * buf,const char * what)252 static void ss(uint32_t *x, uint32_t flag, char *buf, const char *what)
253 {
254 if (strcmp(buf, what) == 0)
255 *x &= ~flag;
256 else
257 *x |= flag;
258 }
259
260 /* Mode db file contains mode definitions like this:
261 * mode "800x600-48-lace"
262 * # D: 36.00 MHz, H: 33.835 kHz, V: 96.39 Hz
263 * geometry 800 600 800 600 8
264 * timings 27778 56 80 79 11 128 12
265 * laced true
266 * hsync high
267 * vsync high
268 * endmode
269 */
read_mode_db(struct fb_var_screeninfo * base,const char * fn,const char * mode)270 static NOINLINE int read_mode_db(struct fb_var_screeninfo *base, const char *fn,
271 const char *mode)
272 {
273 char *token[2], *p, *s;
274 parser_t *parser = config_open(fn);
275
276 while (config_read(parser, token, 2, 1, "# \t\r", PARSE_NORMAL)) {
277 if (strcmp(token[0], "mode") != 0 || !token[1])
278 continue;
279 p = strstr(token[1], mode);
280 if (!p)
281 continue;
282 s = p + strlen(mode);
283 //bb_error_msg("CHECK[%s][%s][%d]", mode, p-1, *s);
284 /* exact match? */
285 if (((!*s || isspace(*s)) && '"' != s[-1]) /* end-of-token */
286 || ('"' == *s && '"' == p[-1]) /* ends with " but starts with " too! */
287 ) {
288 //bb_error_msg("FOUND[%s][%s][%s][%d]", token[1], p, mode, isspace(*s));
289 break;
290 }
291 }
292
293 if (!token[0])
294 return 0;
295
296 while (config_read(parser, token, 2, 1, "# \t", PARSE_NORMAL)) {
297 int i;
298
299 //bb_error_msg("???[%s][%s]", token[0], token[1]);
300 if (strcmp(token[0], "endmode") == 0) {
301 //bb_error_msg("OK[%s]", mode);
302 return 1;
303 }
304 p = token[1];
305 i = index_in_strings(
306 "geometry\0timings\0interlaced\0double\0vsync\0hsync\0csync\0extsync\0rgba\0",
307 token[0]);
308 switch (i) {
309 case 0:
310 if (sizeof(int) == sizeof(base->xres)) {
311 sscanf(p, "%d %d %d %d %d",
312 &base->xres, &base->yres,
313 &base->xres_virtual, &base->yres_virtual,
314 &base->bits_per_pixel);
315 } else {
316 int base_xres, base_yres;
317 int base_xres_virtual, base_yres_virtual;
318 int base_bits_per_pixel;
319 sscanf(p, "%d %d %d %d %d",
320 &base_xres, &base_yres,
321 &base_xres_virtual, &base_yres_virtual,
322 &base_bits_per_pixel);
323 base->xres = base_xres;
324 base->yres = base_yres;
325 base->xres_virtual = base_xres_virtual;
326 base->yres_virtual = base_yres_virtual;
327 base->bits_per_pixel = base_bits_per_pixel;
328 }
329 //bb_error_msg("GEO[%s]", p);
330 break;
331 case 1:
332 if (sizeof(int) == sizeof(base->xres)) {
333 sscanf(p, "%d %d %d %d %d %d %d",
334 &base->pixclock,
335 &base->left_margin, &base->right_margin,
336 &base->upper_margin, &base->lower_margin,
337 &base->hsync_len, &base->vsync_len);
338 } else {
339 int base_pixclock;
340 int base_left_margin, base_right_margin;
341 int base_upper_margin, base_lower_margin;
342 int base_hsync_len, base_vsync_len;
343 sscanf(p, "%d %d %d %d %d %d %d",
344 &base_pixclock,
345 &base_left_margin, &base_right_margin,
346 &base_upper_margin, &base_lower_margin,
347 &base_hsync_len, &base_vsync_len);
348 base->pixclock = base_pixclock;
349 base->left_margin = base_left_margin;
350 base->right_margin = base_right_margin;
351 base->upper_margin = base_upper_margin;
352 base->lower_margin = base_lower_margin;
353 base->hsync_len = base_hsync_len;
354 base->vsync_len = base_vsync_len;
355 }
356 //bb_error_msg("TIM[%s]", p);
357 break;
358 case 2:
359 case 3: {
360 static const uint32_t syncs[] = {FB_VMODE_INTERLACED, FB_VMODE_DOUBLE};
361 ss(&base->vmode, syncs[i-2], p, "false");
362 //bb_error_msg("VMODE[%s]", p);
363 break;
364 }
365 case 4:
366 case 5:
367 case 6: {
368 static const uint32_t syncs[] = {FB_SYNC_VERT_HIGH_ACT, FB_SYNC_HOR_HIGH_ACT, FB_SYNC_COMP_HIGH_ACT};
369 ss(&base->sync, syncs[i-4], p, "low");
370 //bb_error_msg("SYNC[%s]", p);
371 break;
372 }
373 case 7:
374 ss(&base->sync, FB_SYNC_EXT, p, "false");
375 //bb_error_msg("EXTSYNC[%s]", p);
376 break;
377 case 8: {
378 int red_offset, red_length;
379 int green_offset, green_length;
380 int blue_offset, blue_length;
381 int transp_offset, transp_length;
382
383 sscanf(p, "%d/%d,%d/%d,%d/%d,%d/%d",
384 &red_length, &red_offset,
385 &green_length, &green_offset,
386 &blue_length, &blue_offset,
387 &transp_length, &transp_offset);
388 base->red.offset = red_offset;
389 base->red.length = red_length;
390 base->red.msb_right = 0;
391 base->green.offset = green_offset;
392 base->green.length = green_length;
393 base->green.msb_right = 0;
394 base->blue.offset = blue_offset;
395 base->blue.length = blue_length;
396 base->blue.msb_right = 0;
397 base->transp.offset = transp_offset;
398 base->transp.length = transp_length;
399 base->transp.msb_right = 0;
400 }
401 }
402 }
403 return 0;
404 }
405 #endif
406
showmode(struct fb_var_screeninfo * v)407 static NOINLINE void showmode(struct fb_var_screeninfo *v)
408 {
409 double drate = 0, hrate = 0, vrate = 0;
410
411 if (v->pixclock) {
412 drate = 1e12 / v->pixclock;
413 hrate = drate / (v->left_margin + v->xres + v->right_margin + v->hsync_len);
414 vrate = hrate / (v->upper_margin + v->yres + v->lower_margin + v->vsync_len);
415 }
416 printf("\nmode \"%ux%u-%u\"\n"
417 #if ENABLE_FEATURE_FBSET_FANCY
418 "\t# D: %.3f MHz, H: %.3f kHz, V: %.3f Hz\n"
419 #endif
420 "\tgeometry %u %u %u %u %u\n"
421 "\ttimings %u %u %u %u %u %u %u\n"
422 "\taccel %s\n"
423 "\trgba %u/%u,%u/%u,%u/%u,%u/%u\n"
424 "endmode\n\n",
425 v->xres, v->yres, (int) (vrate + 0.5),
426 #if ENABLE_FEATURE_FBSET_FANCY
427 drate / 1e6, hrate / 1e3, vrate,
428 #endif
429 v->xres, v->yres, v->xres_virtual, v->yres_virtual, v->bits_per_pixel,
430 v->pixclock, v->left_margin, v->right_margin, v->upper_margin, v->lower_margin,
431 v->hsync_len, v->vsync_len,
432 (v->accel_flags > 0 ? "true" : "false"),
433 v->red.length, v->red.offset, v->green.length, v->green.offset,
434 v->blue.length, v->blue.offset, v->transp.length, v->transp.offset);
435 }
436
437 int fbset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
fbset_main(int argc,char ** argv)438 int fbset_main(int argc, char **argv)
439 {
440 enum {
441 OPT_CHANGE = (1 << 0),
442 OPT_SHOW = (1 << 1),
443 OPT_READMODE = (1 << 2),
444 OPT_ALL = (1 << 3),
445 };
446 struct fb_var_screeninfo var_old, var_set;
447 int fh, i;
448 unsigned options = 0;
449
450 const char *fbdev = DEFAULTFBDEV;
451 IF_FEATURE_FBSET_READMODE(const char *modefile = DEFAULTFBMODE;)
452 char *thisarg;
453 char *mode = mode; /* for compiler */
454
455 memset(&var_set, 0xff, sizeof(var_set)); /* set all to -1 */
456
457 /* parse cmd args.... why do they have to make things so difficult? */
458 argv++;
459 argc--;
460 for (; argc > 0 && (thisarg = *argv) != NULL; argc--, argv++) {
461 if (thisarg[0] != '-') {
462 if (!ENABLE_FEATURE_FBSET_READMODE || argc != 1)
463 bb_show_usage();
464 mode = thisarg;
465 options |= OPT_READMODE;
466 goto contin;
467 }
468 for (i = 0; i < ARRAY_SIZE(g_cmdoptions); i++) {
469 if (strcmp(thisarg + 1, g_cmdoptions[i].name) != 0)
470 continue;
471 if (argc <= g_cmdoptions[i].param_count)
472 bb_show_usage();
473
474 switch (g_cmdoptions[i].code) {
475 case CMD_FB:
476 fbdev = argv[1];
477 break;
478 case CMD_DB:
479 IF_FEATURE_FBSET_READMODE(modefile = argv[1];)
480 break;
481 case CMD_ALL:
482 options |= OPT_ALL;
483 break;
484 case CMD_SHOW:
485 options |= OPT_SHOW;
486 break;
487 case CMD_GEOMETRY:
488 var_set.xres = xatou32(argv[1]);
489 var_set.yres = xatou32(argv[2]);
490 var_set.xres_virtual = xatou32(argv[3]);
491 var_set.yres_virtual = xatou32(argv[4]);
492 var_set.bits_per_pixel = xatou32(argv[5]);
493 break;
494 case CMD_TIMING:
495 var_set.pixclock = xatou32(argv[1]);
496 var_set.left_margin = xatou32(argv[2]);
497 var_set.right_margin = xatou32(argv[3]);
498 var_set.upper_margin = xatou32(argv[4]);
499 var_set.lower_margin = xatou32(argv[5]);
500 var_set.hsync_len = xatou32(argv[6]);
501 var_set.vsync_len = xatou32(argv[7]);
502 break;
503 case CMD_ACCEL:
504 break;
505 case CMD_HSYNC:
506 var_set.sync |= FB_SYNC_HOR_HIGH_ACT;
507 break;
508 case CMD_VSYNC:
509 var_set.sync |= FB_SYNC_VERT_HIGH_ACT;
510 break;
511 #if ENABLE_FEATURE_FBSET_FANCY
512 case CMD_XRES:
513 var_set.xres = xatou32(argv[1]);
514 break;
515 case CMD_YRES:
516 var_set.yres = xatou32(argv[1]);
517 break;
518 case CMD_DEPTH:
519 var_set.bits_per_pixel = xatou32(argv[1]);
520 break;
521 #endif
522 }
523 switch (g_cmdoptions[i].code) {
524 case CMD_FB:
525 case CMD_DB:
526 case CMD_ALL:
527 case CMD_SHOW:
528 break;
529 default:
530 /* other commands imply changes */
531 options |= OPT_CHANGE;
532 }
533 argc -= g_cmdoptions[i].param_count;
534 argv += g_cmdoptions[i].param_count;
535 goto contin;
536 }
537 bb_show_usage();
538 contin: ;
539 }
540
541 fh = xopen(fbdev, O_RDONLY);
542 xioctl(fh, FBIOGET_VSCREENINFO, &var_old);
543
544 if (options & OPT_READMODE) {
545 #if ENABLE_FEATURE_FBSET_READMODE
546 if (!read_mode_db(&var_old, modefile, mode)) {
547 bb_error_msg_and_die("unknown video mode '%s'", mode);
548 }
549 options |= OPT_CHANGE;
550 #endif
551 }
552
553 if (options & OPT_CHANGE) {
554 copy_changed_values(&var_old, &var_set);
555 if (options & OPT_ALL)
556 var_old.activate = FB_ACTIVATE_ALL;
557 xioctl(fh, FBIOPUT_VSCREENINFO, &var_old);
558 }
559
560 if (options == 0 || (options & OPT_SHOW))
561 showmode(&var_old);
562
563 if (ENABLE_FEATURE_CLEAN_UP)
564 close(fh);
565
566 return EXIT_SUCCESS;
567 }
568