10570 Need workaround to EFI boot on AMI BIOS

@@ -25,10 +25,11 @@
  *
  * Copyright 2017 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  * Copyright (c) 2014 Integros [integros.com]
+ * Copyright (c) 2019, Joyent, Inc.
  */
 
 /*
  * ZFS volume emulation driver.
  *

@@ -1507,21 +1508,21 @@
         if (efi.dki_lba == 1) {
                 efi_gpt_t gpt = { 0 };
 
                 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
                 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
-                gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
+                gpt.efi_gpt_HeaderSize = LE_32(EFI_HEADER_SIZE);
                 gpt.efi_gpt_MyLBA = LE_64(1ULL);
                 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
                 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
                 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
                 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
                 gpt.efi_gpt_SizeOfPartitionEntry =
                     LE_32(sizeof (efi_gpe_t));
                 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
                 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
-                CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
+                CRC32(crc, &gpt, EFI_HEADER_SIZE, -1U, crc32_table);
                 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
                 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
                     flag))
                         return (SET_ERROR(EFAULT));
                 ptr += sizeof (gpt);