misc/fbres.c

   1 /*
   2  * A stupid little program that isn't really useful for anything
   3  * and that has to be here because some people use separate /usr
   4  * partitions.
   5  *
   6  */
   7
   8 #include <stdlib.h>
   9 #include <stdio.h>
  10 #include <stdarg.h>
  11 #include <unistd.h>
  12 #include <string.h>
  13 #include <fcntl.h>
  14 #include <errno.h>
  15 #include <sys/ioctl.h>
  16 #include <ctype.h>
  17 #include <sys/stat.h>
  18 #include <linux/fb.h>
  19
  20 void die(const char *fmt, ...)
  21 {
  22         va_list ap;
  23
  24         fflush(stdout);
  25         va_start(ap, fmt);
  26         vfprintf(stderr, fmt, ap);
  27         va_end(ap);
  28         exit(1);
  29 }
  30
  31 int main(int argc, char *argv[])
  32 {
  33         struct fb_var_screeninfo var;
  34         int fh;
  35         char *xres, *yres;
  36
  37         xres = getenv("SPLASH_XRES");
  38         yres = getenv("SPLASH_YRES");
  39
  40         if (xres && yres && atoi(xres) > 0 && atoi(yres) > 0) {
  41                 printf("%sx%s\n", xres, yres);
  42                 return 0;
  43         }
  44
  45         if ((fh = open("/dev/fb0", O_RDONLY)) == -1)
  46                 if ((fh = open("/dev/fb/0", O_RDONLY)) == -1)
  47                         die("Can't open /dev/fb0 or /dev/fb/0\n");
  48
  49         if (ioctl(fh, FBIOGET_VSCREENINFO, &var))
  50                 die("Can't get fb_var\n");
  51
  52
  53         printf("%dx%d\n", var.xres, var.yres);
  54         close(fh);
  55
  56         return 0;
  57 }