static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n, int *pnum) { bool res; int i; if (n <= 0) { *pnum = 0; return 0; } res = !!memcmp(buf1, buf2, 512); for(i = 1; i < n; i++) { buf1 += 512; buf2 += 512; if (!!memcmp(buf1, buf2, 512) != res) { break; } } *pnum = i; return res; }