[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / DisablePaging64.S

#------------------------------------------------------------------------------
#
# Copyright (c) 2006 - 2008, 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.S
#
# Abstract:
#
#   AsmDisablePaging64 function
#
# Notes:
#
#------------------------------------------------------------------------------

    

#------------------------------------------------------------------------------
# VOID
# EFIAPI
# InternalX86DisablePaging64 (
#   IN      UINT16                    Cs,
#   IN      UINT64                    EntryPoint,
#   IN      UINT64                    Context1,  OPTIONAL
#   IN      UINT32                    Context2,  OPTIONAL
#   IN      UINT64                    NewStack
#   );
#------------------------------------------------------------------------------

.global ASM_PFX(InternalX86DisablePaging64)
ASM_PFX(InternalX86DisablePaging64):
    cli    
    shl    $0x20,%rcx                     # rcx[32..47] <- Cs
    lea    L1, %eax
    mov    %r8d, %esi \r
    or     %rax, %rcx                     # rcx[0..47] <- Cs:@F\r
    mov    %r9d, %edi \r
    mov    0x28(%rsp), %eax               # eax <- New Stack\r
    push   %rcx\r
    ret                                   # switch to compatibility mode\r
L1:
    mov    %eax,%esp                      # set up new stack
    mov    %cr0,%rax
    btr    $0x1f,%eax
    mov    %rax,%cr0                      # disable paging
    mov    $0xc0000080,%ecx
    rdmsr  
    and    $0xfe,%ah                      # clear LME
    wrmsr  
    mov    %cr4,%rax
    and    $0xdf,%al                      # clear PAE
    mov    %rax,%cr4
    push   %rdi                           # push Context2
    push   %rsi                           # push Context1
    callq  *%rdx                          # transfer control to EntryPoint
    jmp    .                              # no one should get here
Commit	Line	Data
f1baef62	1	#------------------------------------------------------------------------------
f1baef62	2	#
c2049caa	3	# Copyright (c) 2006 - 2008, Intel Corporation
f1baef62	4	# All rights reserved. This program and the accompanying materials
	5	# are licensed and made available under the terms and conditions of the BSD License
	6	# which accompanies this distribution. The full text of the license may be found at
	7	# http://opensource.org/licenses/bsd-license.php
	8	#
	9	# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
	10	# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
	11	#
	12	# Module Name:
	13	#
	14	# DisablePaging64.S
	15	#
	16	# Abstract:
	17	#
	18	# AsmDisablePaging64 function
	19	#
	20	# Notes:
	21	#
	22	#------------------------------------------------------------------------------
	23
	24
	25
	26	#------------------------------------------------------------------------------
	27	# VOID
	28	# EFIAPI
	29	# InternalX86DisablePaging64 (
2faf4da5	30	# IN UINT16 Cs,
	31	# IN UINT64 EntryPoint,
	32	# IN UINT64 Context1, OPTIONAL
	33	# IN UINT32 Context2, OPTIONAL
	34	# IN UINT64 NewStack
f1baef62	35	# );
	36	#------------------------------------------------------------------------------
	37
85c25283	38	.global ASM_PFX(InternalX86DisablePaging64)
85c25283	39	ASM_PFX(InternalX86DisablePaging64):
f1baef62	40	cli
2faf4da5	41	shl $0x20,%rcx # rcx[32..47] <- Cs
c2049caa	42	lea L1, %eax
c2049caa	43	mov %r8d, %esi \r
2faf4da5	44	or %rax, %rcx # rcx[0..47] <- Cs:@F\r
c2049caa	45	mov %r9d, %edi \r
2faf4da5	46	mov 0x28(%rsp), %eax # eax <- New Stack\r
c2049caa	47	push %rcx\r
2faf4da5	48	ret # switch to compatibility mode\r
f1baef62	49	L1:
2faf4da5	50	mov %eax,%esp # set up new stack
f1baef62	51	mov %cr0,%rax
f1baef62	52	btr $0x1f,%eax
2faf4da5	53	mov %rax,%cr0 # disable paging
f1baef62	54	mov $0xc0000080,%ecx
f1baef62	55	rdmsr
2faf4da5	56	and $0xfe,%ah # clear LME
f1baef62	57	wrmsr
f1baef62	58	mov %cr4,%rax
2faf4da5	59	and $0xdf,%al # clear PAE
f1baef62	60	mov %rax,%cr4
2faf4da5	61	push %rdi # push Context2
	62	push %rsi # push Context1
	63	callq *%rdx # transfer control to EntryPoint
	64	jmp . # no one should get here
f1baef62	65