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

#------------------------------------------------------------------------------\r
#\r
# Copyright (c) 2006 - 2008, Intel Corporation\r
# All rights reserved. This program and the accompanying materials\r
# are licensed and made available under the terms and conditions of the BSD License\r
# which accompanies this distribution.  The full text of the license may be found at\r
# http://opensource.org/licenses/bsd-license.php\r
#\r
# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
#\r
# Module Name:\r
#\r
#   DisablePaging64.S\r
#\r
# Abstract:\r
#\r
#   AsmDisablePaging64 function\r
#\r
# Notes:\r
#\r
#------------------------------------------------------------------------------\r
\r
    \r
\r
#------------------------------------------------------------------------------\r
# VOID\r
# EFIAPI\r
# InternalX86DisablePaging64 (\r
#   IN      UINT16                    Cs,\r
#   IN      UINT32                    EntryPoint,\r
#   IN      UINT32                    Context1,  OPTIONAL\r
#   IN      UINT32                    Context2,  OPTIONAL\r
#   IN      UINT32                    NewStack\r
#   );\r
#------------------------------------------------------------------------------\r
\r
ASM_GLOBAL ASM_PFX(InternalX86DisablePaging64)\r
ASM_PFX(InternalX86DisablePaging64):\r
    cli    
    lea    L1(%rip), %rsi                 # rsi <- The start address of transition code
    mov    0x28(%rsp), %rdi               # rdi <- New stack
    sub    $64, %rdi                      # rdi <- use 64 byte in stack to hold transition code  
    mov    %rdi, %r10                     # r10 <- The start address of transicition code below 4G
    lea    _mTransitionEnd(%rip), %rax    # rax <- end of transition code
    sub    %rsi, %rax                     # rax <- The size of transition piece code
    push   %rcx                           # save rcx to stack
    mov    %rax, %rcx                     # rcx <- The size of transition piece code
    rep
    movsb                                 # copy transition code to (new stack - 64byte) below 4G
    pop    %rcx                           # restore rcx
   \r
    mov    %r8d, %esi \r
    mov    %r9d, %edi \r
    mov    0x28(%rsp), %eax               # eax <- New Stack\r
    push   %rcx                           # push Cs to stack\r
    push   %r10\r
    .byte  0x48, 0xcb                     # retq: Use far return to load CS register from stack\r
                                          # (Use raw byte code since some GNU assemblers generates incorrect code for "retq")  \r
L1:\r
    mov    %eax,%esp                      # set up new stack\r
    mov    %cr0,%rax\r
    btr    $0x1f,%eax\r
    mov    %rax,%cr0                      # disable paging\r
\r
    mov    %rdx,%rbx                      # save EntryPoint to rbx, for rdmsr will overwrite rdx\r
    mov    $0xc0000080,%ecx\r
    rdmsr  \r
    and    $0xfe,%ah                      # clear LME\r
    wrmsr  \r
    mov    %cr4,%rax\r
    and    $0xdf,%al                      # clear PAE\r
    mov    %rax,%cr4\r
    push   %rdi                           # push Context2\r
    push   %rsi                           # push Context1\r
    callq  *%rbx                          # transfer control to EntryPoint\r
    jmp    .                              # no one should get here\r
\r_mTransitionEnd :
Commit	Line	Data
b1ff428c	1	#------------------------------------------------------------------------------\r
	2	#\r
	3	# Copyright (c) 2006 - 2008, Intel Corporation\r
	4	# All rights reserved. This program and the accompanying materials\r
	5	# are licensed and made available under the terms and conditions of the BSD License\r
	6	# which accompanies this distribution. The full text of the license may be found at\r
	7	# http://opensource.org/licenses/bsd-license.php\r
	8	#\r
	9	# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	10	# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	11	#\r
	12	# Module Name:\r
	13	#\r
	14	# DisablePaging64.S\r
	15	#\r
	16	# Abstract:\r
	17	#\r
	18	# AsmDisablePaging64 function\r
	19	#\r
	20	# Notes:\r
	21	#\r
	22	#------------------------------------------------------------------------------\r
	23	\r
	24	\r
	25	\r
	26	#------------------------------------------------------------------------------\r
	27	# VOID\r
	28	# EFIAPI\r
	29	# InternalX86DisablePaging64 (\r
	30	# IN UINT16 Cs,\r
2561f565	31	# IN UINT32 EntryPoint,\r
2561f565	32	# IN UINT32 Context1, OPTIONAL\r
b1ff428c	33	# IN UINT32 Context2, OPTIONAL\r
2561f565	34	# IN UINT32 NewStack\r
b1ff428c	35	# );\r
	36	#------------------------------------------------------------------------------\r
	37	\r
d5172f91	38	ASM_GLOBAL ASM_PFX(InternalX86DisablePaging64)\r
b1ff428c	39	ASM_PFX(InternalX86DisablePaging64):\r
2e56bb15	40	cli
	41	lea L1(%rip), %rsi # rsi <- The start address of transition code
	42	mov 0x28(%rsp), %rdi # rdi <- New stack
	43	sub $64, %rdi # rdi <- use 64 byte in stack to hold transition code
	44	mov %rdi, %r10 # r10 <- The start address of transicition code below 4G
	45	lea _mTransitionEnd(%rip), %rax # rax <- end of transition code
	46	sub %rsi, %rax # rax <- The size of transition piece code
	47	push %rcx # save rcx to stack
	48	mov %rax, %rcx # rcx <- The size of transition piece code
	49	rep
	50	movsb # copy transition code to (new stack - 64byte) below 4G
	51	pop %rcx # restore rcx
	52	\r
c2049caa	53	mov %r8d, %esi \r
c2049caa	54	mov %r9d, %edi \r
2faf4da5	55	mov 0x28(%rsp), %eax # eax <- New Stack\r
2561f565	56	push %rcx # push Cs to stack\r
	57	push %r10\r
	58	.byte 0x48, 0xcb # retq: Use far return to load CS register from stack\r
	59	# (Use raw byte code since some GNU assemblers generates incorrect code for "retq") \r
b1ff428c	60	L1:\r
	61	mov %eax,%esp # set up new stack\r
	62	mov %cr0,%rax\r
	63	btr $0x1f,%eax\r
	64	mov %rax,%cr0 # disable paging\r
63d7211e	65	\r
63d7211e	66	mov %rdx,%rbx # save EntryPoint to rbx, for rdmsr will overwrite rdx\r
b1ff428c	67	mov $0xc0000080,%ecx\r
	68	rdmsr \r
	69	and $0xfe,%ah # clear LME\r
	70	wrmsr \r
	71	mov %cr4,%rax\r
	72	and $0xdf,%al # clear PAE\r
	73	mov %rax,%cr4\r
	74	push %rdi # push Context2\r
	75	push %rsi # push Context1\r
63d7211e	76	callq *%rbx # transfer control to EntryPoint\r
b1ff428c	77	jmp . # no one should get here\r
2e56bb15	78	\r_mTransitionEnd :