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-rw-r--r--ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S8
1 files changed, 8 insertions, 0 deletions
diff --git a/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S b/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S
index f2a517671f..0e9f9d0453 100644
--- a/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S
+++ b/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S
@@ -165,4 +165,12 @@ ASM_FUNC(ArmWriteCpuActlr)
isb
bx lr
+ASM_FUNC (ArmGetPhysicalAddressBits)
+ mrc p15, 0, r0, c0, c1, 4 // MMFR0
+ and r0, r0, #0xf // VMSA [3:0]
+ cmp r0, #5 // >= 5 implies LPAE support
+ movlt r0, #32 // 32 bits if no LPAE
+ movge r0, #40 // 40 bits if LPAE
+ bx lr
+
ASM_FUNCTION_REMOVE_IF_UNREFERENCED