From e1853c66214fc7f6039457ff10bdaedcc7381f53 Mon Sep 17 00:00:00 2001
From: Sylas Hollander <distrohopper39b.business@gmail.com>
Date: Sun, 1 Mar 2026 14:26:35 -0500
Subject: [PATCH] [FREELDR:UEFI] Correctly pass through ACPI information and
 map its memory (#8669)

This prevents bugchecks in Windows due to the ACPI table being overwritten
because of the incorrect UEFI to E820 memory mappings.

CORE-11954
---
 boot/freeldr/freeldr/arch/uefi/uefihw.c  | 9 ++-------
 boot/freeldr/freeldr/arch/uefi/uefimem.c | 4 ++--
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/boot/freeldr/freeldr/arch/uefi/uefihw.c b/boot/freeldr/freeldr/arch/uefi/uefihw.c
index 584c2a43d7b..3f5edb2322e 100644
--- a/boot/freeldr/freeldr/arch/uefi/uefihw.c
+++ b/boot/freeldr/freeldr/arch/uefi/uefihw.c
@@ -18,8 +18,6 @@ DBG_DEFAULT_CHANNEL(WARNING);
 extern EFI_SYSTEM_TABLE * GlobalSystemTable;
 extern EFI_HANDLE GlobalImageHandle;
 extern UCHAR PcBiosDiskCount;
-extern EFI_MEMORY_DESCRIPTOR* EfiMemoryMap;
-extern UINT32 FreeldrDescCount;
 
 /* From uefivid.c */
 extern ULONG_PTR VramAddress;
@@ -74,8 +72,7 @@ DetectAcpiBios(PCONFIGURATION_COMPONENT_DATA SystemKey, ULONG *BusNumber)
         AcpiPresent = TRUE;
 
         /* Calculate the table size */
-        TableSize = FreeldrDescCount * sizeof(BIOS_MEMORY_MAP) +
-            sizeof(ACPI_BIOS_DATA) - sizeof(BIOS_MEMORY_MAP);
+        TableSize = sizeof(ACPI_BIOS_DATA);
 
         /* Set 'Configuration Data' value */
         Size = FIELD_OFFSET(CM_PARTIAL_RESOURCE_LIST, PartialDescriptors[1]) + TableSize;
@@ -110,9 +107,7 @@ DetectAcpiBios(PCONFIGURATION_COMPONENT_DATA SystemKey, ULONG *BusNumber)
             AcpiBiosData->RSDTAddress.LowPart = Rsdp->rsdt_physical_address;
         }
 
-        AcpiBiosData->Count = FreeldrDescCount;
-        RtlCopyMemory(AcpiBiosData->MemoryMap, EfiMemoryMap,
-                      FreeldrDescCount * sizeof(BIOS_MEMORY_MAP));
+        AcpiBiosData->Count = 0;
 
         TRACE("RSDT %p, data size %x\n", Rsdp->rsdt_physical_address, TableSize);
 
diff --git a/boot/freeldr/freeldr/arch/uefi/uefimem.c b/boot/freeldr/freeldr/arch/uefi/uefimem.c
index cbaf3c6b885..0097711cc3d 100644
--- a/boot/freeldr/freeldr/arch/uefi/uefimem.c
+++ b/boot/freeldr/freeldr/arch/uefi/uefimem.c
@@ -127,9 +127,9 @@ UefiConvertToFreeldrDesc(EFI_MEMORY_TYPE EfiMemoryType)
         case EfiUnusableMemory:
             return LoaderBad;
         case EfiACPIReclaimMemory:
-            return LoaderFirmwareTemporary;
+            return LoaderSpecialMemory;
         case EfiACPIMemoryNVS:
-            return LoaderReserve;
+            return LoaderSpecialMemory;
         case EfiMemoryMappedIO:
             return LoaderReserve;
         case EfiMemoryMappedIOPortSpace: