rve/example/example.c

#include "printf.h"

typedef unsigned long long uint64_t;
typedef unsigned long uint32_t;
#define MTIME_BASE 0x0200BFF8

uint64_t read_mtime_atomic() {
  uint32_t upper1, lower, upper2;

  do {
    upper1 = *(uint32_t*)(MTIME_BASE + 4);
    lower = *(uint32_t*)(MTIME_BASE);
    upper2 = *(uint32_t*)(MTIME_BASE + 4);
  } while (upper1 != upper2); // Repeat if upper changed during the process

  return ((uint64_t)upper1 << 32) | lower;
}

int fact(int n) {
  if (n == 0)
    return 1;

  return n * fact(n-1);
}

int main() {
  int n = 8;
  int res = fact(8);

  printf("sizeof(long) = %d\n", sizeof(long long));
  printf("%d! = %d\n", n, res);

  return 0;
}