| ;------------------------------------------------------------------------------ | |
| ; | |
| ; Copyright (c) 2006, Intel Corporation | |
| ; All rights reserved. This program and the accompanying materials | |
| ; are licensed and made available under the terms and conditions of the BSD License | |
| ; which accompanies this distribution. The full text of the license may be found at | |
| ; http://opensource.org/licenses/bsd-license.php | |
| ; | |
| ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
| ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
| ; | |
| ; Module Name: | |
| ; | |
| ; DisablePaging64.Asm | |
| ; | |
| ; Abstract: | |
| ; | |
| ; AsmDisablePaging64 function | |
| ; | |
| ; Notes: | |
| ; | |
| ;------------------------------------------------------------------------------ | |
| .code | |
| ;------------------------------------------------------------------------------ | |
| ; VOID | |
| ; EFIAPI | |
| ; InternalX86DisablePaging64 ( | |
| ; IN UINT16 Cs, | |
| ; IN UINT32 EntryPoint, | |
| ; IN UINT32 Context1, OPTIONAL | |
| ; IN UINT32 Context2, OPTIONAL | |
| ; IN UINT32 NewStack | |
| ; ); | |
| ;------------------------------------------------------------------------------ | |
| InternalX86DisablePaging64 PROC | |
| cli | |
| shl rcx, 32 ; rcx[32..47] <- Cs | |
| lea eax, @F | |
| mov esi, r8d | |
| or rcx, rax ; rcx[0..47] <- Cs:@F | |
| mov edi, r9d | |
| mov eax, [rsp + 28h] ; eax <- New Stack | |
| push rcx | |
| retf ; switch to compatibility mode | |
| @@: | |
| mov esp, eax ; set up new stack | |
| mov rax, cr0 | |
| btr eax, 31 | |
| mov cr0, rax ; disable paging | |
| mov ecx, 0c0000080h | |
| rdmsr | |
| and ah, NOT 1 ; clear LME | |
| wrmsr | |
| mov rax, cr4 | |
| and al, NOT (1 SHL 5) ; clear PAE | |
| mov cr4, rax | |
| push rdi ; push Context2 | |
| push rsi ; push Context1 | |
| call rdx ; transfer control to EntryPoint | |
| hlt ; no one should get here | |
| InternalX86DisablePaging64 ENDP | |
| END |