hdr_length
if (addr + length > (char *)madt + madt->hdr_length)
p_dsdt->hdr_length - sizeof(p_dsdt->hdr));
p_dsdt->hdr_length - sizeof(p_dsdt->hdr));
p_dsdt->hdr_length - sizeof(p_dsdt->hdr));
tmp.length = p_ssdt->hdr_length - sizeof(p_ssdt->hdr);