ArmPlatformPkg/PrePi: Fixed register corruption

The commit on Fri Dec 6 2013: "ArmPlatformPkg/ArmPlatformStackLib:
Do not directly use PcdArmPrimaryCore" has made the function
ArmPlatformStackSet() overwrites the registers r6 and r7.
These registers are used by PrePi to store the MPIDR and the the base
of the system memory region used by UEFI.

Change-Id: I69ff80cb5a298c89cba1680b148eb306f47a6375

2 files changed, 34 insertions, 34 deletions

diff --git a/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S b/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S
index 50671aecd..4fe10addc 100644
--- a/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S
+++ b/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S
@@ -1,5 +1,5 @@
 //

-//  Copyright (c) 2011-2013, ARM Limited. All rights reserved.

+//  Copyright (c) 2011-2014, 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

@@ -38,7 +38,7 @@ ASM_PFX(_ModuleEntryPoint):
   // Get ID of this CPU in Multicore system

   bl    ASM_PFX(ArmReadMpidr)

   // Keep a copy of the MpId register value

-  mov   r6, r0

+  mov   r8, r0

 

 _SetSVCMode:

   // Enter SVC mode, Disable FIQ and IRQ

@@ -83,47 +83,47 @@ _SetupStack:
   // Because the 'push' instruction is equivalent to 'stmdb' (decrement before), we need to increment

   // one to the top of the stack. We check if incrementing one does not overflow (case of DRAM at the

   // top of the memory space)

-  adds  r7, r1, #1

+  adds  r9, r1, #1

   bcs   _SetupOverflowStack

 

 _SetupAlignedStack:

-  mov   r1, r7

+  mov   r1, r9

   b     _GetBaseUefiMemory

 

 _SetupOverflowStack:

   // Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE

   // aligned (4KB)

-  LoadConstantToReg (EFI_PAGE_MASK, r7)

-  and   r7, r7, r1

-  sub   r1, r1, r7

+  LoadConstantToReg (EFI_PAGE_MASK, r9)

+  and   r9, r9, r1

+  sub   r1, r1, r9

 

 _GetBaseUefiMemory:

   // Calculate the Base of the UEFI Memory

-  sub   r7, r1, r4

+  sub   r9, r1, r4

 

 _GetStackBase:

   // r1 = The top of the Mpcore Stacks

   // Stack for the primary core = PrimaryCoreStack

   LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)

-  sub   r8, r1, r2

+  sub   r10, r1, r2

 

   // Stack for the secondary core = Number of Cores - 1

   LoadConstantToReg (FixedPcdGet32(PcdCoreCount), r0)

   sub	r0, r0, #1

   LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r1)

   mul   r1, r1, r0

-  sub   r8, r8, r1

+  sub   r10, r10, r1

 

-  // r8 = The base of the MpCore Stacks (primary stack & secondary stacks)

-  mov	r0, r8

-  mov	r1, r6

+  // r10 = The base of the MpCore Stacks (primary stack & secondary stacks)

+  mov	r0, r10

+  mov	r1, r8

   //ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)

   LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)

   LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r3)

   bl	ASM_PFX(ArmPlatformStackSet)

 

   // Is it the Primary Core ?

-  mov   r0, r6

+  mov   r0, r8

   bl    ASM_PFX(ArmPlatformIsPrimaryCore)

   cmp   r0, #1

   bne   _PrepareArguments

@@ -134,9 +134,9 @@ _ReserveGlobalVariable:
   InitializePrimaryStack(r0, r1)

 

 _PrepareArguments:

-  mov   r0, r6

-  mov   r1, r7

-  mov   r2, r8

+  mov   r0, r8

+  mov   r1, r9

+  mov   r2, r10

   mov   r3, sp

 

   // Move sec startup address into a data register

diff --git a/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.asm b/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.asm
index f76b62e5d..028a9a1b2 100644
--- a/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.asm
+++ b/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.asm
@@ -1,5 +1,5 @@
 //

-//  Copyright (c) 2011-2013, ARM Limited. All rights reserved.

+//  Copyright (c) 2011-2014, 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

@@ -40,7 +40,7 @@ _ModuleEntryPoint
   // Get ID of this CPU in Multicore system

   bl    ArmReadMpidr

   // Keep a copy of the MpId register value

-  mov   r6, r0

+  mov   r8, r0

 

 _SetSVCMode

   // Enter SVC mode, Disable FIQ and IRQ

@@ -85,47 +85,47 @@ _SetupStack
   // Because the 'push' instruction is equivalent to 'stmdb' (decrement before), we need to increment

   // one to the top of the stack. We check if incrementing one does not overflow (case of DRAM at the

   // top of the memory space)

-  adds  r7, r1, #1

+  adds  r9, r1, #1

   bcs   _SetupOverflowStack

 

 _SetupAlignedStack

-  mov   r1, r7

+  mov   r1, r9

   b     _GetBaseUefiMemory

 

 _SetupOverflowStack

   // Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE

   // aligned (4KB)

-  LoadConstantToReg (EFI_PAGE_MASK, r7)

-  and   r7, r7, r1

-  sub   r1, r1, r7

+  LoadConstantToReg (EFI_PAGE_MASK, r9)

+  and   r9, r9, r1

+  sub   r1, r1, r9

 

 _GetBaseUefiMemory

   // Calculate the Base of the UEFI Memory

-  sub   r7, r1, r4

+  sub   r9, r1, r4

 

 _GetStackBase

   // r1 = The top of the Mpcore Stacks

   // Stack for the primary core = PrimaryCoreStack

   LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)

-  sub   r8, r1, r2

+  sub   r10, r1, r2

 

   // Stack for the secondary core = Number of Cores - 1

   LoadConstantToReg (FixedPcdGet32(PcdCoreCount), r0)

   sub	r0, r0, #1

   LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r1)

   mul   r1, r1, r0

-  sub   r8, r8, r1

+  sub   r10, r10, r1

 

-  // r8 = The base of the MpCore Stacks (primary stack & secondary stacks)

-  mov	r0, r8

-  mov	r1, r6

+  // r10 = The base of the MpCore Stacks (primary stack & secondary stacks)

+  mov	r0, r10

+  mov	r1, r8

   //ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)

   LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)

   LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r3)

   bl	ArmPlatformStackSet

 

   // Is it the Primary Core ?

-  mov   r0, r6

+  mov   r0, r8

   bl    ArmPlatformIsPrimaryCore

   cmp   r0, #1

   bne   _PrepareArguments

@@ -136,9 +136,9 @@ _ReserveGlobalVariable
   InitializePrimaryStack r0, r1

 

 _PrepareArguments

-  mov   r0, r6

-  mov   r1, r7

-  mov   r2, r8

+  mov   r0, r8

+  mov   r1, r9

+  mov   r2, r10

   mov   r3, sp

 

   // Move sec startup address into a data register