Contributed-under: TianoCore Contribution Agreement 1.0 Signed off by: Jiewen Yao <jiewen.yao@intel.com> Reviewed by: Ravi Rangarajan <ravi.p.rangarajan@intel.com> Reviewed by: Maurice Ma <maurice.ma@intel.com> Reviewed by: Giri Mudusuru <giri.p.mudusuru@intel.com> Reviewed by: Liming Gao <liming.gao@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15676 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			78 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| #------------------------------------------------------------------------------
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| #
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| # Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
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| # This program and the accompanying materials
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| # are licensed and made available under the terms and conditions of the BSD License
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| # which accompanies this distribution.  The full text of the license may be found at
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| # http://opensource.org/licenses/bsd-license.php.
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| #
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| # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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| # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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| #
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| # Abstract:
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| #
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| #   Switch the stack from temporary memory to permenent memory.
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| #
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| #------------------------------------------------------------------------------
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| 
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| 
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| #------------------------------------------------------------------------------
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| # VOID
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| # EFIAPI
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| # SecSwitchStack (
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| #   UINT32   TemporaryMemoryBase,
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| #   UINT32   PermenentMemoryBase
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| #   )#
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| #------------------------------------------------------------------------------
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| ASM_GLOBAL ASM_PFX (SecSwitchStack)
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| ASM_PFX(SecSwitchStack):
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|     #
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|     # Save standard registers so they can be used to change stack
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|     #
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|     pushl %eax
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|     pushl %ebx
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|     pushl %ecx
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|     pushl %edx
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| 
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|     #
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|     # !!CAUTION!! this function address's is pushed into stack after
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|     # migration of whole temporary memory, so need save it to permenent
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|     # memory at first!
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|     #
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|     movl  20(%esp), %ebx         # Save the first parameter
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|     movl  24(%esp), %ecx         # Save the second parameter
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| 
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|     #
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|     # Save this function's return address into permenent memory at first.
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|     # Then, Fixup the esp point to permenent memory
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|     #
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|     movl  %esp, %eax
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|     subl  %ebx, %eax
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|     addl  %ecx, %eax
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|     movl  0(%esp), %edx          # copy pushed register's value to permenent memory
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|     movl  %edx, 0(%eax)
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|     movl  4(%esp), %edx
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|     movl  %edx, 4(%eax)
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|     movl  8(%esp), %edx
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|     movl  %edx, 8(%eax)
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|     movl  12(%esp), %edx
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|     movl  %edx, 12(%eax)
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|     movl  16(%esp), %edx        # Update this function's return address into permenent memory
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|     movl  %edx, 16(%eax)
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|     movl  %eax, %esp            # From now, esp is pointed to permenent memory
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| 
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|     #
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|     # Fixup the ebp point to permenent memory
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|     #
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|     movl  %ebp, %eax
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|     subl  %ebx, %eax
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|     addl  %ecx, %eax
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|     movl  %eax, %ebp            # From now, ebp is pointed to permenent memory
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| 
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|     popl  %edx
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|     popl  %ecx
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|     popl  %ebx
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|     popl  %eax
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|     ret
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| 
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