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 char __malloc_start[512];
   8
   9 void rot13(char *buf)
  10 {
  11     while (*buf) {
  12         if ((*buf >= 'a' && *buf <= 'm') ||
  13                 (*buf >= 'A' && *buf <= 'M')) {
  14             *buf += 13;
  15         } else if ((*buf >= 'n' && *buf <= 'z') ||
  16                 (*buf >= 'N' && *buf <= 'Z')) {
  17             *buf -= 13;
  18         }
  19         buf++;
  20     }
  21 }
  22
  23 size_t strlen(const char *buf)
  24 {
  25     int len = 0;
  26     while (buf[len])
  27         len++;
  28     return len;
  29 }
  30
  31 // TODO: These should be local to main, but if I make them global then gdb can
  32 // find them.
  33 static volatile int i;
  34 static int j;
  35 int main()
  36 {
  37     i = 0;
  38     j = 0;
  39     char *fox = "The quick brown fox jumps of the lazy dog.";
  40     unsigned int checksum = 0;
  41
  42 start:
  43     while (i)
  44         j++;
  45
  46     rot13(fox);
  47     checksum ^= crc32a(fox, strlen(fox));
  48     rot13(fox);
  49     checksum ^= crc32a(fox, strlen(fox));
  50
  51     return checksum;
  52 }