SIZEOF_SDT_HDR
write(fd, hdr, SIZEOF_SDT_HDR);
write(fd, hdr->body, hdr->len - SIZEOF_SDT_HDR);
entries = (rsdp->len - SIZEOF_SDT_HDR) / sizeof(u_int32_t);
entries = (rsdp->len - SIZEOF_SDT_HDR) / sizeof(u_int64_t);
entries = (rsdp->len - SIZEOF_SDT_HDR) / sizeof(u_int32_t);
entries = (rsdp->len - SIZEOF_SDT_HDR) / sizeof(u_int64_t);