From f6ceca9c723bb9e91e71e666b73beefa95494a3b Mon Sep 17 00:00:00 2001
From: Goldfish64 <goldfishnet@aol.com>
Date: Thu, 9 Jul 2020 20:27:20 -0500
Subject: [PATCH] DxeIpl: Fix ACPI reset register detection

---
 Legacy/BootPlatform/DxeIpl/LegacyTable.c | 30 ++++++++++++++++++------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/Legacy/BootPlatform/DxeIpl/LegacyTable.c b/Legacy/BootPlatform/DxeIpl/LegacyTable.c
index b6a06563..9ce17cda 100644
--- a/Legacy/BootPlatform/DxeIpl/LegacyTable.c
+++ b/Legacy/BootPlatform/DxeIpl/LegacyTable.c
@@ -307,12 +307,28 @@ PrepareFadtTable (
       );
   }
   if (Fadt->Header.Length >= OFFSET_OF (EFI_ACPI_3_0_FIXED_ACPI_DESCRIPTION_TABLE, ResetValue) + sizeof (Fadt->ResetValue)) {
-    CopyMem (
-      &AcpiDescription->RESET_REG,
-      &Fadt->ResetReg,
-      sizeof(EFI_ACPI_3_0_GENERIC_ADDRESS_STRUCTURE)
-      );
-    AcpiDescription->RESET_VALUE = Fadt->ResetValue;
+    //
+    // Ensure FADT register information is valid and can be trusted before using.
+    // If not, use universal register settings. See AcpiFadtEnableReset() in OcAcpiLib.
+    //
+    if (Fadt->ResetReg.Address != 0 && Fadt->ResetReg.RegisterBitWidth == 8) {
+      CopyMem (
+        &AcpiDescription->RESET_REG,
+        &Fadt->ResetReg,
+        sizeof(EFI_ACPI_3_0_GENERIC_ADDRESS_STRUCTURE)
+        );
+      AcpiDescription->RESET_VALUE = Fadt->ResetValue;
+    } else {
+      //
+      // Use mostly universal default of 0xCF9.
+      //
+      AcpiDescription->RESET_REG.Address = 0xCF9;
+      AcpiDescription->RESET_REG.AddressSpaceId = EFI_ACPI_3_0_SYSTEM_IO;
+      AcpiDescription->RESET_REG.RegisterBitWidth = 8;
+      AcpiDescription->RESET_REG.RegisterBitOffset = 0;
+      AcpiDescription->RESET_REG.AccessSize = EFI_ACPI_3_0_BYTE;
+      AcpiDescription->RESET_VALUE = 6;
+    }
   } else {
     //
     // ** CHANGE START **
@@ -322,7 +338,7 @@ PrepareFadtTable (
     AcpiDescription->RESET_REG.AddressSpaceId = EFI_ACPI_3_0_SYSTEM_IO;
     AcpiDescription->RESET_REG.RegisterBitWidth = 8;
     AcpiDescription->RESET_REG.RegisterBitOffset = 0;
-    AcpiDescription->RESET_REG.AccessSize = 1;
+    AcpiDescription->RESET_REG.AccessSize = EFI_ACPI_3_0_BYTE;
     AcpiDescription->RESET_VALUE = 0xFE;
     //
     // ** CHANGE END **