debug/programs/debug.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdint.h>
   4
   5 unsigned int crc32a(uint8_t *message, unsigned int size);
   6
   7 void rot13(char *buf)
   8 {
   9     while (*buf) {
  10         if ((*buf >= 'a' && *buf <= 'm') ||
  11                 (*buf >= 'A' && *buf <= 'M')) {
  12             *buf += 13;
  13         } else if ((*buf >= 'n' && *buf <= 'z') ||
  14                 (*buf >= 'N' && *buf <= 'Z')) {
  15             *buf -= 13;
  16         }
  17         buf++;
  18     }
  19 }
  20
  21 size_t strlen(const char *buf)
  22 {
  23     int len = 0;
  24     while (buf[len])
  25         len++;
  26     return len;
  27 }
  28
  29 // TODO: These should be local to main, but if I make them global then gdb can
  30 // find them.
  31 static volatile int i;
  32 static int j;
  33 int main()
  34 {
  35     i = 0;
  36     j = 0;
  37     char *fox = "The quick brown fox jumps of the lazy dog.";
  38     unsigned int checksum = 0;
  39
  40 start:
  41     while (i)
  42         j++;
  43
  44     rot13(fox);
  45     checksum ^= crc32a(fox, strlen(fox));
  46     rot13(fox);
  47     checksum ^= crc32a(fox, strlen(fox));
  48
  49     return checksum;
  50 }