4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync;------------------------------------------------------------------------------
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; This program and the accompanying materials
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; are licensed and made available under the terms and conditions of the BSD License
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; which accompanies this distribution. The full text of the license may be found at
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; Module Name:
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; AsmDisablePaging64 function
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync;------------------------------------------------------------------------------
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync;------------------------------------------------------------------------------
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; InternalX86DisablePaging64 (
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; IN UINT16 Cs,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; IN UINT32 EntryPoint,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; IN UINT32 Context1, OPTIONAL
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; IN UINT32 Context2, OPTIONAL
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; IN UINT32 NewStack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync;------------------------------------------------------------------------------
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncInternalX86DisablePaging64 PROC
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync lea rsi, @F ; rsi <- The start address of transition code
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov edi, [rsp + 28h] ; rdi <- New stack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync lea rax, mTransitionEnd ; rax <- end of transition code
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync sub rax, rsi ; rax <- The size of transition piece code
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync add rax, 4 ; Round RAX up to the next 4 byte boundary
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync and al, 0fch
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync sub rdi, rax ; rdi <- Use stack to hold transition code
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov r10d, edi ; r10 <- The start address of transicition code below 4G
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync push rcx ; save rcx to stack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov rcx, rax ; rcx <- The size of transition piece code
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync rep movsb ; copy transition code to top of new stack which must be below 4GB
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync pop rcx ; restore rcx
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov esi, r8d
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov edi, r9d
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov eax, r10d ; eax <- start of the transition code on the stack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync sub eax, 4 ; eax <- One slot below transition code on the stack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync push rcx ; push Cs to stack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync push r10 ; push address of tansition code on stack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync DB 48h ; prefix to composite "retq" with next "retf"
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync retf ; Use far return to load CS register from stack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync; Start of transition code
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov esp, eax ; set up new stack
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov rax, cr0
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync btr eax, 31 ; Clear CR0.PG
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov cr0, rax ; disable paging and caches
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov ebx, edx ; save EntryPoint to rbx, for rdmsr will overwrite rdx
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov ecx, 0c0000080h
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync and ah, NOT 1 ; clear LME
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov rax, cr4
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync and al, NOT (1 SHL 5) ; clear PAE
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync mov cr4, rax
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync push rdi ; push Context2
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync push rsi ; push Context1
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync call rbx ; transfer control to EntryPoint
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync hlt ; no one should get here
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncInternalX86DisablePaging64 ENDP
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncmTransitionEnd LABEL BYTE