diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h
index 85fa1f600b..15f610d82e 100644
--- a/ArmPkg/Include/Library/ArmLib.h
+++ b/ArmPkg/Include/Library/ArmLib.h
@@ -1,7 +1,7 @@
/** @file
Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.
- Copyright (c) 2011 - 2015, ARM Ltd. All rights reserved.
+ Copyright (c) 2011 - 2016, ARM Ltd. All rights reserved.
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
@@ -353,6 +353,12 @@ ArmSetTTBR0 (
IN VOID *TranslationTableBase
);
+VOID
+EFIAPI
+ArmSetTTBCR (
+ IN UINT32 Bits
+ );
+
VOID *
EFIAPI
ArmGetTTBR0BaseAddress (
diff --git a/ArmPkg/Library/ArmLib/ArmV7/ArmV7Mmu.c b/ArmPkg/Library/ArmLib/ArmV7/ArmV7Mmu.c
index fc8ea42843..74a7c177df 100644
--- a/ArmPkg/Library/ArmLib/ArmV7/ArmV7Mmu.c
+++ b/ArmPkg/Library/ArmLib/ArmV7/ArmV7Mmu.c
@@ -1,7 +1,7 @@
/** @file
* File managing the MMU for ARMv7 architecture
*
-* Copyright (c) 2011-2013, ARM Limited. All rights reserved.
+* Copyright (c) 2011-2016, ARM Limited. All rights reserved.
*
* This program and the accompanying materials
* are licensed and made available under the terms and conditions of the BSD License
@@ -347,6 +347,17 @@ ArmConfigureMmu (
ArmSetTTBR0 ((VOID *)(UINTN)(((UINTN)TranslationTable & ~TRANSLATION_TABLE_SECTION_ALIGNMENT_MASK) | (TTBRAttributes & 0x7F)));
+ //
+ // The TTBCR register value is undefined at reset in the Non-Secure world.
+ // Writing 0 has the effect of:
+ // Clearing EAE: Use short descriptors, as mandated by specification.
+ // Clearing PD0 and PD1: Translation Table Walk Disable is off.
+ // Clearing N: Perform all translation table walks through TTBR0.
+ // (0 is the default reset value in systems not implementing
+ // the Security Extensions.)
+ //
+ ArmSetTTBCR (0);
+
ArmSetDomainAccessControl (DOMAIN_ACCESS_CONTROL_NONE(15) |
DOMAIN_ACCESS_CONTROL_NONE(14) |
DOMAIN_ACCESS_CONTROL_NONE(13) |
diff --git a/ArmPkg/Library/ArmLib/Common/Arm/ArmLibSupport.S b/ArmPkg/Library/ArmLib/Common/Arm/ArmLibSupport.S
index 085f08bfda..5d1194e7e2 100644
--- a/ArmPkg/Library/ArmLib/Common/Arm/ArmLibSupport.S
+++ b/ArmPkg/Library/ArmLib/Common/Arm/ArmLibSupport.S
@@ -1,7 +1,7 @@
#------------------------------------------------------------------------------
#
# Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.
-# Copyright (c) 2011 - 2014, ARM Limited. All rights reserved.
+# Copyright (c) 2011 - 2016, ARM Limited. All rights reserved.
#
# This program and the accompanying materials
# are licensed and made available under the terms and conditions of the BSD License
@@ -23,6 +23,7 @@ GCC_ASM_EXPORT(ArmGetInterruptState)
GCC_ASM_EXPORT(ArmGetFiqState)
GCC_ASM_EXPORT(ArmGetTTBR0BaseAddress)
GCC_ASM_EXPORT(ArmSetTTBR0)
+GCC_ASM_EXPORT(ArmSetTTBCR)
GCC_ASM_EXPORT(ArmSetDomainAccessControl)
GCC_ASM_EXPORT(CPSRMaskInsert)
GCC_ASM_EXPORT(CPSRRead)
@@ -111,6 +112,11 @@ ASM_PFX(ArmSetTTBR0):
isb
bx lr
+ASM_PFX(ArmSetTTBCR):
+ mcr p15, 0, r0, c2, c0, 2
+ isb
+ bx lr
+
ASM_PFX(ArmGetTTBR0BaseAddress):
mrc p15,0,r0,c2,c0,0
LoadConstantToReg(0xFFFFC000, r1)
diff --git a/ArmPkg/Library/ArmLib/Common/Arm/ArmLibSupport.asm b/ArmPkg/Library/ArmLib/Common/Arm/ArmLibSupport.asm
index 228d7c8fc1..9b87b7f257 100644
--- a/ArmPkg/Library/ArmLib/Common/Arm/ArmLibSupport.asm
+++ b/ArmPkg/Library/ArmLib/Common/Arm/ArmLibSupport.asm
@@ -1,7 +1,7 @@
//------------------------------------------------------------------------------
//
// Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.
-// Copyright (c) 2011 - 2014, ARM Limited. All rights reserved.
+// Copyright (c) 2011 - 2016, ARM Limited. All rights reserved.
//
// This program and the accompanying materials
// are licensed and made available under the terms and conditions of the BSD License
@@ -85,6 +85,11 @@
isb
bx lr
+ RVCT_ASM_EXPORT ArmSetTTBCR
+ mcr p15, 0, r0, c2, c0, 2
+ isb
+ bx lr
+
RVCT_ASM_EXPORT ArmGetTTBR0BaseAddress
mrc p15,0,r0,c2,c0,0
LoadConstantToReg(0xFFFFC000, r1)