tests/regread.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <sys/types.h>
   4 #include <sys/stat.h>
   5 #include <fcntl.h>
   6 #include <sys/mman.h>
   7 #include <unistd.h>
   8
   9 int main(int argc, char *argv[])
  10 {
  11         volatile unsigned int *regs;
  12         unsigned int nreg, val;
  13         int memdev;
  14         char *p;
  15
  16         if (argc < 2)
  17         {
  18                 printf("%s <reg> [val]\n", argv[0]);
  19                 return 1;
  20         }
  21
  22         nreg = strtoul(argv[1], &p, 0);
  23         if (*p != 0)
  24         {
  25                 printf("bad arg 1\n");
  26                 return 1;
  27         }
  28
  29         memdev = open("/dev/mem", O_RDWR|O_SYNC);
  30         if (memdev == -1)
  31         {
  32                 perror("open /dev/mem");
  33                 return 1;
  34         }
  35
  36         regs = mmap(0, 0x1000, PROT_WRITE|PROT_READ, MAP_SHARED, memdev, nreg & ~0xfff);
  37         if (regs == MAP_FAILED)
  38         {
  39                 close(memdev);
  40                 perror("mmap");
  41                 return 1;
  42         }
  43
  44         printf(" = 0x%08x\n", regs[(nreg&0xfff)>>2]);
  45
  46         if (argc == 3)
  47         {
  48                 val = strtoul(argv[2], &p, 0);
  49                 if (*p != 0)
  50                 {
  51                         printf("bad arg 2\n");
  52                         return 1;
  53                 }
  54
  55                 regs[(nreg&0xfff)>>2] = val;
  56                 printf("val set.\n");
  57         }
  58
  59         munmap((void *)regs, 0x1000);
  60         close(memdev);
  61
  62         return 0;
  63 }
  64