DISK_readbytes
int DISK_readbytes(void *, const uint64_t, const size_t);
if (DISK_readbytes(&legh, sector, sizeof(legh)))
if (DISK_readbytes(legp, gh.gh_part_lba, gpbytes))
if (DISK_readbytes(&legh, GPTSECTOR, sizeof(legh)))
if (DISK_readbytes(&legh, DL_GETDSIZE(&dl) - 1, sizeof(legh)))
if (DISK_readbytes(&dos_mbr, lba_self, sizeof(dos_mbr)))