gpt_read
mbr = gpt_read(gpt, 0LL, 1);
mbr = gpt_read(gpt, lba, 1);
hdr = gpt_read(gpt, lba, 1);
p = gpt_read(gpt, (off_t)le64toh((uint64_t)hdr->hdr_lba_table), blocks);
void* gpt_read(gpt_t, off_t, size_t);
buf = gpt_read(gpt, start + LABELSECTOR, 1);
mbr = gpt_read(gpt, 0LL, 1);