git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7250 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			68 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			68 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| #------------------------------------------------------------------------------
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| #
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| # Copyright (c) 2006 - 2008, Intel Corporation
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| # All rights reserved. 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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| # Module Name:
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| #
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| #   DisablePaging64.S
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| #
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| # Abstract:
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| #
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| #   AsmDisablePaging64 function
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| #
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| # Notes:
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| #
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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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| # InternalX86DisablePaging64 (
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| #   IN      UINT16                    Cs,
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| #   IN      UINT64                    EntryPoint,
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| #   IN      UINT64                    Context1,  OPTIONAL
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| #   IN      UINT32                    Context2,  OPTIONAL
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| #   IN      UINT64                    NewStack
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| #   );
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| #------------------------------------------------------------------------------
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| 
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| .global ASM_PFX(InternalX86DisablePaging64)
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| ASM_PFX(InternalX86DisablePaging64):
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|     cli    
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|     shl    $0x20,%rcx                     # rcx[32..47] <- Cs
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|     lea    L1, %eax
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|     mov    %r8d, %esi 
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|     or     %rax, %rcx                     # rcx[0..47] <- Cs:@F
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|     mov    %r9d, %edi 
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|     mov    0x28(%rsp), %eax               # eax <- New Stack
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|     push   %rcx
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|     ret                                   # switch to compatibility mode
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| L1:
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|     mov    %eax,%esp                      # set up new stack
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|     mov    %cr0,%rax
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|     btr    $0x1f,%eax
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|     mov    %rax,%cr0                      # disable paging
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| 
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|     mov    %rdx,%rbx                      # save EntryPoint to rbx, for rdmsr will overwrite rdx
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|     mov    $0xc0000080,%ecx
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|     rdmsr  
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|     and    $0xfe,%ah                      # clear LME
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|     wrmsr  
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|     mov    %cr4,%rax
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|     and    $0xdf,%al                      # clear PAE
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|     mov    %rax,%cr4
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|     push   %rdi                           # push Context2
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|     push   %rsi                           # push Context1
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|     callq  *%rbx                          # transfer control to EntryPoint
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|     jmp    .                              # no one should get here
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| 
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