EFI_SYSTEM_TABLE_SIGNATURE
.signature = EFI_SYSTEM_TABLE_SIGNATURE,
if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)