1 /* vi: set sw=4 ts=4: */
3 * Mini fbset implementation for busybox
5 * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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)
15 //config: bool "fbset (5.8 kb)"
17 //config: select PLATFORM_LINUX
19 //config: fbset is used to show or change the settings of a Linux frame buffer
20 //config: device. The frame buffer device provides a simple and unique
21 //config: interface to access a graphics display. Enable this option
22 //config: if you wish to enable the 'fbset' utility.
24 //config:config FEATURE_FBSET_FANCY
25 //config: bool "Enable extra options"
27 //config: depends on FBSET
29 //config: This option enables extended fbset options, allowing one to set the
30 //config: framebuffer size, color depth, etc. interface to access a graphics
31 //config: display. Enable this option if you wish to enable extended fbset
34 //config:config FEATURE_FBSET_READMODE
35 //config: bool "Enable readmode support"
37 //config: depends on FBSET
39 //config: This option allows fbset to read the video mode database stored by
40 //config: default as /etc/fb.modes, which can be used to set frame buffer
41 //config: device to pre-defined video modes.
43 //applet:IF_FBSET(APPLET(fbset, BB_DIR_USR_SBIN, BB_SUID_DROP))
45 //kbuild:lib-$(CONFIG_FBSET) += fbset.o
47 //usage:#define fbset_trivial_usage
48 //usage: "[OPTIONS] [MODE]"
49 //usage:#define fbset_full_usage "\n\n"
50 //usage: "Show and modify frame buffer settings"
52 //usage:#define fbset_example_usage
54 //usage: "mode \"1024x768-76\"\n"
55 //usage: " # D: 78.653 MHz, H: 59.949 kHz, V: 75.694 Hz\n"
56 //usage: " geometry 1024 768 1024 768 16\n"
57 //usage: " timings 12714 128 32 16 4 128 4\n"
58 //usage: " accel false\n"
59 //usage: " rgba 5/11,6/5,5/0,0/0\n"
64 #define DEFAULTFBDEV FB_0
65 #define DEFAULTFBMODE "/etc/fb.modes"
67 /* Stuff stolen from the kernel's fb.h */
68 #define FB_ACTIVATE_ALL 64
70 FBIOGET_VSCREENINFO = 0x4600,
71 FBIOPUT_VSCREENINFO = 0x4601
75 uint32_t offset; /* beginning of bitfield */
76 uint32_t length; /* length of bitfield */
77 uint32_t msb_right; /* !=0: Most significant bit is right */
79 struct fb_var_screeninfo {
80 uint32_t xres; /* visible resolution */
82 uint32_t xres_virtual; /* virtual resolution */
83 uint32_t yres_virtual;
84 uint32_t xoffset; /* offset from virtual to visible */
85 uint32_t yoffset; /* resolution */
87 uint32_t bits_per_pixel;
88 uint32_t grayscale; /* !=0 Graylevels instead of colors */
90 struct fb_bitfield red; /* bitfield in fb mem if true color, */
91 struct fb_bitfield green; /* else only length is significant */
92 struct fb_bitfield blue;
93 struct fb_bitfield transp; /* transparency */
95 uint32_t nonstd; /* !=0 Non standard pixel format */
97 uint32_t activate; /* see FB_ACTIVATE_x */
99 uint32_t height; /* height of picture in mm */
100 uint32_t width; /* width of picture in mm */
102 uint32_t accel_flags; /* acceleration flags (hints) */
104 /* Timing: All values in pixclocks, except pixclock (of course) */
105 uint32_t pixclock; /* pixel clock in ps (pico seconds) */
106 uint32_t left_margin; /* time from sync to picture */
107 uint32_t right_margin; /* time from picture to sync */
108 uint32_t upper_margin; /* time from sync to picture */
109 uint32_t lower_margin;
110 uint32_t hsync_len; /* length of horizontal sync */
111 uint32_t vsync_len; /* length of vertical sync */
112 uint32_t sync; /* see FB_SYNC_x */
113 uint32_t vmode; /* see FB_VMODE_x */
114 uint32_t reserved[6]; /* Reserved for future compatibility */
117 static void copy_if_gt0(uint32_t *src, uint32_t *dst, unsigned cnt)
120 if ((int32_t) *src > 0)
127 static NOINLINE void copy_changed_values(
128 struct fb_var_screeninfo *base,
129 struct fb_var_screeninfo *set)
131 //if ((int32_t) set->xres > 0) base->xres = set->xres;
132 //if ((int32_t) set->yres > 0) base->yres = set->yres;
133 //if ((int32_t) set->xres_virtual > 0) base->xres_virtual = set->xres_virtual;
134 //if ((int32_t) set->yres_virtual > 0) base->yres_virtual = set->yres_virtual;
135 copy_if_gt0(&set->xres, &base->xres, 4);
137 if ((int32_t) set->bits_per_pixel > 0) base->bits_per_pixel = set->bits_per_pixel;
138 //copy_if_gt0(&set->bits_per_pixel, &base->bits_per_pixel, 1);
140 //if ((int32_t) set->pixclock > 0) base->pixclock = set->pixclock;
141 //if ((int32_t) set->left_margin > 0) base->left_margin = set->left_margin;
142 //if ((int32_t) set->right_margin > 0) base->right_margin = set->right_margin;
143 //if ((int32_t) set->upper_margin > 0) base->upper_margin = set->upper_margin;
144 //if ((int32_t) set->lower_margin > 0) base->lower_margin = set->lower_margin;
145 //if ((int32_t) set->hsync_len > 0) base->hsync_len = set->hsync_len;
146 //if ((int32_t) set->vsync_len > 0) base->vsync_len = set->vsync_len;
147 //if ((int32_t) set->sync > 0) base->sync = set->sync;
148 //if ((int32_t) set->vmode > 0) base->vmode = set->vmode;
149 copy_if_gt0(&set->pixclock, &base->pixclock, 9);
163 /* CMD_XCOMPAT = 10, */
169 #if ENABLE_FEATURE_FBSET_FANCY
193 static const struct cmdoptions_t {
195 const unsigned char param_count;
196 const unsigned char code;
198 /*"12345678" + NUL */
199 //TODO: convert to index_in_strings()
200 { "fb" , 1, CMD_FB },
201 { "db" , 1, CMD_DB },
202 { "a" , 0, CMD_ALL },
203 { "i" , 0, CMD_INFO },
204 { "g" , 5, CMD_GEOMETRY },
205 { "t" , 7, CMD_TIMING },
206 { "accel" , 1, CMD_ACCEL },
207 { "hsync" , 1, CMD_HSYNC },
208 { "vsync" , 1, CMD_VSYNC },
209 { "laced" , 1, CMD_LACED },
210 { "double" , 1, CMD_DOUBLE },
211 { "show" , 0, CMD_SHOW },
212 { "s" , 0, CMD_SHOW },
213 #if ENABLE_FEATURE_FBSET_FANCY
214 { "all" , 0, CMD_ALL },
215 { "xres" , 1, CMD_XRES },
216 { "yres" , 1, CMD_YRES },
217 { "vxres" , 1, CMD_VXRES },
218 { "vyres" , 1, CMD_VYRES },
219 { "depth" , 1, CMD_DEPTH },
220 { "match" , 0, CMD_MATCH },
221 { "geometry", 5, CMD_GEOMETRY },
222 { "pixclock", 1, CMD_PIXCLOCK },
223 { "left" , 1, CMD_LEFT },
224 { "right" , 1, CMD_RIGHT },
225 { "upper" , 1, CMD_UPPER },
226 { "lower" , 1, CMD_LOWER },
227 { "hslen" , 1, CMD_HSLEN },
228 { "vslen" , 1, CMD_VSLEN },
229 { "timings" , 7, CMD_TIMING },
230 { "csync" , 1, CMD_CSYNC },
231 { "gsync" , 1, CMD_GSYNC },
232 { "extsync" , 1, CMD_EXTSYNC },
233 { "bcast" , 1, CMD_BCAST },
234 { "rgba" , 1, CMD_RGBA },
235 { "step" , 1, CMD_STEP },
236 { "move" , 1, CMD_MOVE },
240 /* taken from linux/fb.h */
242 FB_SYNC_HOR_HIGH_ACT = 1, /* horizontal sync high active */
243 FB_SYNC_VERT_HIGH_ACT = 2, /* vertical sync high active */
244 #if ENABLE_FEATURE_FBSET_READMODE
245 FB_VMODE_INTERLACED = 1, /* interlaced */
246 FB_VMODE_DOUBLE = 2, /* double scan */
247 FB_SYNC_EXT = 4, /* external sync */
248 FB_SYNC_COMP_HIGH_ACT = 8, /* composite sync high active */
252 #if ENABLE_FEATURE_FBSET_READMODE
253 static void ss(uint32_t *x, uint32_t flag, char *buf, const char *what)
255 if (strcmp(buf, what) == 0)
261 /* Mode db file contains mode definitions like this:
262 * mode "800x600-48-lace"
263 * # D: 36.00 MHz, H: 33.835 kHz, V: 96.39 Hz
264 * geometry 800 600 800 600 8
265 * timings 27778 56 80 79 11 128 12
271 static int read_mode_db(struct fb_var_screeninfo *base, const char *fn,
274 char *token[2], *p, *s;
275 parser_t *parser = config_open(fn);
277 while (config_read(parser, token, 2, 1, "# \t\r", PARSE_NORMAL)) {
278 if (strcmp(token[0], "mode") != 0 || !token[1])
280 p = strstr(token[1], mode);
283 s = p + strlen(mode);
284 //bb_error_msg("CHECK[%s][%s][%d]", mode, p-1, *s);
286 if (((!*s || isspace(*s)) && '"' != s[-1]) /* end-of-token */
287 || ('"' == *s && '"' == p[-1]) /* ends with " but starts with " too! */
289 //bb_error_msg("FOUND[%s][%s][%s][%d]", token[1], p, mode, isspace(*s));
297 while (config_read(parser, token, 2, 1, "# \t", PARSE_NORMAL)) {
300 //bb_error_msg("???[%s][%s]", token[0], token[1]);
301 if (strcmp(token[0], "endmode") == 0) {
302 //bb_error_msg("OK[%s]", mode);
306 i = index_in_strings(
307 "geometry\0timings\0interlaced\0double\0vsync\0hsync\0csync\0extsync\0rgba\0",
311 if (sizeof(int) == sizeof(base->xres)) {
312 sscanf(p, "%d %d %d %d %d",
313 &base->xres, &base->yres,
314 &base->xres_virtual, &base->yres_virtual,
315 &base->bits_per_pixel);
317 int base_xres, base_yres;
318 int base_xres_virtual, base_yres_virtual;
319 int base_bits_per_pixel;
320 sscanf(p, "%d %d %d %d %d",
321 &base_xres, &base_yres,
322 &base_xres_virtual, &base_yres_virtual,
323 &base_bits_per_pixel);
324 base->xres = base_xres;
325 base->yres = base_yres;
326 base->xres_virtual = base_xres_virtual;
327 base->yres_virtual = base_yres_virtual;
328 base->bits_per_pixel = base_bits_per_pixel;
330 //bb_error_msg("GEO[%s]", p);
333 if (sizeof(int) == sizeof(base->xres)) {
334 sscanf(p, "%d %d %d %d %d %d %d",
336 &base->left_margin, &base->right_margin,
337 &base->upper_margin, &base->lower_margin,
338 &base->hsync_len, &base->vsync_len);
341 int base_left_margin, base_right_margin;
342 int base_upper_margin, base_lower_margin;
343 int base_hsync_len, base_vsync_len;
344 sscanf(p, "%d %d %d %d %d %d %d",
346 &base_left_margin, &base_right_margin,
347 &base_upper_margin, &base_lower_margin,
348 &base_hsync_len, &base_vsync_len);
349 base->pixclock = base_pixclock;
350 base->left_margin = base_left_margin;
351 base->right_margin = base_right_margin;
352 base->upper_margin = base_upper_margin;
353 base->lower_margin = base_lower_margin;
354 base->hsync_len = base_hsync_len;
355 base->vsync_len = base_vsync_len;
357 //bb_error_msg("TIM[%s]", p);
361 static const uint32_t syncs[] = {FB_VMODE_INTERLACED, FB_VMODE_DOUBLE};
362 ss(&base->vmode, syncs[i-2], p, "false");
363 //bb_error_msg("VMODE[%s]", p);
369 static const uint32_t syncs[] = {FB_SYNC_VERT_HIGH_ACT, FB_SYNC_HOR_HIGH_ACT, FB_SYNC_COMP_HIGH_ACT};
370 ss(&base->sync, syncs[i-4], p, "low");
371 //bb_error_msg("SYNC[%s]", p);
375 ss(&base->sync, FB_SYNC_EXT, p, "false");
376 //bb_error_msg("EXTSYNC[%s]", p);
379 int red_offset, red_length;
380 int green_offset, green_length;
381 int blue_offset, blue_length;
382 int transp_offset, transp_length;
384 sscanf(p, "%d/%d,%d/%d,%d/%d,%d/%d",
385 &red_length, &red_offset,
386 &green_length, &green_offset,
387 &blue_length, &blue_offset,
388 &transp_length, &transp_offset);
389 base->red.offset = red_offset;
390 base->red.length = red_length;
391 base->red.msb_right = 0;
392 base->green.offset = green_offset;
393 base->green.length = green_length;
394 base->green.msb_right = 0;
395 base->blue.offset = blue_offset;
396 base->blue.length = blue_length;
397 base->blue.msb_right = 0;
398 base->transp.offset = transp_offset;
399 base->transp.length = transp_length;
400 base->transp.msb_right = 0;
408 static NOINLINE void showmode(struct fb_var_screeninfo *v)
410 double drate = 0, hrate = 0, vrate = 0;
413 drate = 1e12 / v->pixclock;
414 hrate = drate / (v->left_margin + v->xres + v->right_margin + v->hsync_len);
415 vrate = hrate / (v->upper_margin + v->yres + v->lower_margin + v->vsync_len);
417 printf("\nmode \"%ux%u-%u\"\n"
418 #if ENABLE_FEATURE_FBSET_FANCY
419 "\t# D: %.3f MHz, H: %.3f kHz, V: %.3f Hz\n"
421 "\tgeometry %u %u %u %u %u\n"
422 "\ttimings %u %u %u %u %u %u %u\n"
424 "\trgba %u/%u,%u/%u,%u/%u,%u/%u\n"
426 v->xres, v->yres, (int) (vrate + 0.5),
427 #if ENABLE_FEATURE_FBSET_FANCY
428 drate / 1e6, hrate / 1e3, vrate,
430 v->xres, v->yres, v->xres_virtual, v->yres_virtual, v->bits_per_pixel,
431 v->pixclock, v->left_margin, v->right_margin, v->upper_margin, v->lower_margin,
432 v->hsync_len, v->vsync_len,
433 (v->accel_flags > 0 ? "true" : "false"),
434 v->red.length, v->red.offset, v->green.length, v->green.offset,
435 v->blue.length, v->blue.offset, v->transp.length, v->transp.offset);
438 int fbset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
439 int fbset_main(int argc, char **argv)
442 OPT_CHANGE = (1 << 0),
444 OPT_READMODE = (1 << 2),
447 struct fb_var_screeninfo var_old, var_set;
449 unsigned options = 0;
451 const char *fbdev = DEFAULTFBDEV;
452 IF_FEATURE_FBSET_READMODE(const char *modefile = DEFAULTFBMODE;)
454 char *mode = mode; /* for compiler */
456 memset(&var_set, 0xff, sizeof(var_set)); /* set all to -1 */
458 /* parse cmd args.... why do they have to make things so difficult? */
461 for (; argc > 0 && (thisarg = *argv) != NULL; argc--, argv++) {
462 if (thisarg[0] != '-') {
463 if (!ENABLE_FEATURE_FBSET_READMODE || argc != 1)
466 options |= OPT_READMODE;
469 for (i = 0; i < ARRAY_SIZE(g_cmdoptions); i++) {
470 if (strcmp(thisarg + 1, g_cmdoptions[i].name) != 0)
472 if (argc <= g_cmdoptions[i].param_count)
475 switch (g_cmdoptions[i].code) {
480 IF_FEATURE_FBSET_READMODE(modefile = argv[1];)
489 var_set.xres = xatou32(argv[1]);
490 var_set.yres = xatou32(argv[2]);
491 var_set.xres_virtual = xatou32(argv[3]);
492 var_set.yres_virtual = xatou32(argv[4]);
493 var_set.bits_per_pixel = xatou32(argv[5]);
496 var_set.pixclock = xatou32(argv[1]);
497 var_set.left_margin = xatou32(argv[2]);
498 var_set.right_margin = xatou32(argv[3]);
499 var_set.upper_margin = xatou32(argv[4]);
500 var_set.lower_margin = xatou32(argv[5]);
501 var_set.hsync_len = xatou32(argv[6]);
502 var_set.vsync_len = xatou32(argv[7]);
507 var_set.sync |= FB_SYNC_HOR_HIGH_ACT;
510 var_set.sync |= FB_SYNC_VERT_HIGH_ACT;
512 #if ENABLE_FEATURE_FBSET_FANCY
514 var_set.xres = xatou32(argv[1]);
517 var_set.yres = xatou32(argv[1]);
520 var_set.bits_per_pixel = xatou32(argv[1]);
524 switch (g_cmdoptions[i].code) {
531 /* other commands imply changes */
532 options |= OPT_CHANGE;
534 argc -= g_cmdoptions[i].param_count;
535 argv += g_cmdoptions[i].param_count;
542 fh = xopen(fbdev, O_RDONLY);
543 xioctl(fh, FBIOGET_VSCREENINFO, &var_old);
545 if (options & OPT_READMODE) {
546 #if ENABLE_FEATURE_FBSET_READMODE
547 if (!read_mode_db(&var_old, modefile, mode)) {
548 bb_error_msg_and_die("unknown video mode '%s'", mode);
550 options |= OPT_CHANGE;
554 if (options & OPT_CHANGE) {
555 copy_changed_values(&var_old, &var_set);
556 if (options & OPT_ALL)
557 var_old.activate = FB_ACTIVATE_ALL;
558 xioctl(fh, FBIOPUT_VSCREENINFO, &var_old);
561 if (options == 0 || (options & OPT_SHOW))
564 if (ENABLE_FEATURE_CLEAN_UP)