debug/programs/debug.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdint.h>
   4 #include <stdlib.h>
   5
   6 unsigned int crc32a(uint8_t *message, unsigned int size);
   7
   8 unsigned int fib(unsigned int n)
   9 {
  10     if (n == 0) {
  11         return 0;
  12     }
  13
  14     unsigned int a = 0;
  15     unsigned int b = 1;
  16
  17     for (unsigned int i = 1; i < n; i++) {
  18         unsigned int next = a + b;
  19         a = b;
  20         b = next;
  21     }
  22
  23     return b;
  24 }
  25
  26 void rot13(char *buf)
  27 {
  28     while (*buf) {
  29         if ((*buf >= 'a' && *buf <= 'm') ||
  30                 (*buf >= 'A' && *buf <= 'M')) {
  31             *buf += 13;
  32         } else if ((*buf >= 'n' && *buf <= 'z') ||
  33                 (*buf >= 'N' && *buf <= 'Z')) {
  34             *buf -= 13;
  35         }
  36         buf++;
  37     }
  38 }
  39
  40 size_t strlen(const char *buf)
  41 {
  42     int len = 0;
  43     while (buf[len])
  44         len++;
  45     return len;
  46 }
  47
  48 extern void *__malloc_freelist;
  49
  50 int main()
  51 {
  52     __malloc_freelist = 0;
  53
  54     volatile int i = 0;
  55     int j = 0;
  56     char *fox = "The quick brown fox jumps of the lazy dog.";
  57     unsigned int checksum = 0;
  58
  59 start:
  60     while (i)
  61         j++;
  62
  63     rot13(fox);
  64     checksum ^= crc32a(fox, strlen(fox));
  65     rot13(fox);
  66     checksum ^= crc32a(fox, strlen(fox));
  67
  68     return checksum;
  69 }