diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
index e51acd0551..6c2688b4a4 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
@@ -1238,6 +1238,24 @@ GenericLegacyBoot (
                            0x40000,
                            &Granularity
                            );
+
+  if ((Private->Legacy16Table->TableLength >= OFFSET_OF (EFI_COMPATIBILITY16_TABLE, HiPermanentMemoryAddress)) &&
+      ((Private->Legacy16Table->UmaAddress != 0) && (Private->Legacy16Table->UmaSize != 0))) {
+    //
+    // Here we could reduce UmaAddress down as far as Private->OptionRom, taking into
+    // account the granularity of the access control.
+    //
+    DEBUG((EFI_D_INFO, "Unlocking UMB RAM region 0x%x-0x%x\n", Private->Legacy16Table->UmaAddress,
+                        Private->Legacy16Table->UmaAddress + Private->Legacy16Table->UmaSize));
+
+    Private->LegacyRegion->UnLock (
+                             Private->LegacyRegion,
+                             Private->Legacy16Table->UmaAddress,
+                             Private->Legacy16Table->UmaSize,
+                             &Granularity
+                             );
+  }
+
   //
   // Lock attributes of the Legacy Region if chipset supports
   //
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
index 7299fc0e6b..9d84ab0000 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
@@ -1,6 +1,6 @@
 /** @file
 
-Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
 
 This program and the accompanying materials
 are licensed and made available under the terms and conditions
@@ -2284,6 +2284,7 @@ LegacyBiosInstallRom (
   UINT32                LocalTime;
   UINT32                StartBbsIndex;
   UINT32                EndBbsIndex;
+  UINT32                MaxRomAddr;
   UINTN                 TempData;
   UINTN                 InitAddress;
   UINTN                 RuntimeAddress;
@@ -2299,6 +2300,15 @@ LegacyBiosInstallRom (
   Function        = 0;
   VideoMode       = 0;
   PhysicalAddress = 0;
+  MaxRomAddr      = PcdGet32 (PcdEndOpromShadowAddress);
+
+  if ((Private->Legacy16Table->TableLength >= OFFSET_OF(EFI_COMPATIBILITY16_TABLE, HiPermanentMemoryAddress)) &&
+      (Private->Legacy16Table->UmaAddress != 0) && 
+      (Private->Legacy16Table->UmaSize != 0) &&
+      (MaxRomAddr > (Private->Legacy16Table->UmaAddress))) {
+    MaxRomAddr = Private->Legacy16Table->UmaAddress;
+  }
+
 
   PciProgramAllInterruptLineRegisters (Private);
 
@@ -2331,7 +2341,7 @@ LegacyBiosInstallRom (
     //   then test if there is enough space for its RT code
     //
     RuntimeAddress = Private->OptionRom;
-    if (RuntimeAddress + *RuntimeImageLength > PcdGet32 (PcdEndOpromShadowAddress)) {
+    if (RuntimeAddress + *RuntimeImageLength > MaxRomAddr) {
       DEBUG ((EFI_D_ERROR, "return LegacyBiosInstallRom(%d): EFI_OUT_OF_RESOURCES (no more space for OpROM)\n", __LINE__));
       gBS->FreePages (PhysicalAddress, EFI_SIZE_TO_PAGES (ImageSize));
       //
@@ -2349,7 +2359,7 @@ LegacyBiosInstallRom (
     //   test if there is enough space for its INIT code
     //
     InitAddress    = PCI_START_ADDRESS (Private->OptionRom);
-    if (InitAddress + ImageSize > PcdGet32 (PcdEndOpromShadowAddress)) {
+    if (InitAddress + ImageSize > MaxRomAddr) {
       DEBUG ((EFI_D_ERROR, "return LegacyBiosInstallRom(%d): EFI_OUT_OF_RESOURCES (no more space for OpROM)\n", __LINE__));
       //
       // Report Status Code to indicate that there is no enough space for OpROM