diff options
Diffstat (limited to 'IntelFsp2WrapperPkg/Library/BaseFspWrapperApiLib/X64/Thunk64To32.S')
| -rw-r--r-- | IntelFsp2WrapperPkg/Library/BaseFspWrapperApiLib/X64/Thunk64To32.S | 230 |
1 files changed, 0 insertions, 230 deletions
diff --git a/IntelFsp2WrapperPkg/Library/BaseFspWrapperApiLib/X64/Thunk64To32.S b/IntelFsp2WrapperPkg/Library/BaseFspWrapperApiLib/X64/Thunk64To32.S deleted file mode 100644 index b6b5c1aca8..0000000000 --- a/IntelFsp2WrapperPkg/Library/BaseFspWrapperApiLib/X64/Thunk64To32.S +++ /dev/null @@ -1,230 +0,0 @@ -#
-# Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
-# 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:
-#
-# Thunk64To32.asm
-#
-# Abstract:
-#
-# This is the assembly code to transition from long mode to compatibility mode to execute 32-bit code and then
-# transit back to long mode.
-#
-#-------------------------------------------------------------------------------
-
-#----------------------------------------------------------------------------
-# Procedure: AsmExecute32BitCode
-#
-# Input: None
-#
-# Output: None
-#
-# Prototype: UINT32
-# AsmExecute32BitCode (
-# IN UINT64 Function,
-# IN UINT64 Param1,
-# IN UINT64 Param2,
-# IN IA32_DESCRIPTOR *InternalGdtr
-# );
-#
-#
-# Description: A thunk function to execute 32-bit code in long mode.
-#
-#----------------------------------------------------------------------------
-
-ASM_GLOBAL ASM_PFX(AsmExecute32BitCode)
-ASM_PFX(AsmExecute32BitCode):
- #
- # save IFLAG and disable it
- #
- pushfq
- cli
-
- #
- # save orignal GDTR and CS
- #
- movl %ds, %eax
- push %rax
- movl %cs, %eax
- push %rax
- subq $0x10, %rsp
- sgdt (%rsp)
- #
- # load internal GDT
- #
- lgdt (%r9)
- #
- # Save general purpose register and rflag register
- #
- pushfq
- push %rdi
- push %rsi
- push %rbp
- push %rbx
-
- #
- # save CR3
- #
- movq %cr3, %rax
- movq %rax, %rbp
-
- #
- # Prepare the CS and return address for the transition from 32-bit to 64-bit mode
- #
- movq $0x10, %rax # load long mode selector
- shl $32, %rax
- lea ReloadCS(%rip), %r9 #Assume the ReloadCS is under 4G
- orq %r9, %rax
- push %rax
- #
- # Save parameters for 32-bit function call
- #
- movq %r8, %rax
- shl $32, %rax
- orq %rdx, %rax
- push %rax
- #
- # save the 32-bit function entry and the return address into stack which will be
- # retrieve in compatibility mode.
- #
- lea ReturnBack(%rip), %rax #Assume the ReloadCS is under 4G
- shl $32, %rax
- orq %rcx, %rax
- push %rax
-
- #
- # let rax save DS
- #
- movq $0x18, %rax
-
- #
- # Change to Compatible Segment
- #
- movq $8, %rcx # load compatible mode selector
- shl $32, %rcx
- lea Compatible(%rip), %rdx # assume address < 4G
- orq %rdx, %rcx
- push %rcx
- .byte 0xcb # retf
-
-Compatible:
- # reload DS/ES/SS to make sure they are correct referred to current GDT
- movw %ax, %ds
- movw %ax, %es
- movw %ax, %ss
-
- #
- # Disable paging
- #
- movq %cr0, %rcx
- btc $31, %ecx
- movq %rcx, %cr0
- #
- # Clear EFER.LME
- #
- movl $0xC0000080, %ecx
- rdmsr
- btc $8, %eax
- wrmsr
-
-# Now we are in protected mode
- #
- # Call 32-bit function. Assume the function entry address and parameter value is less than 4G
- #
- pop %rax # Here is the function entry
- #
- # Now the parameter is at the bottom of the stack, then call in to IA32 function.
- #
- jmp *%rax
-ReturnBack:
- movl %eax, %ebx # save return status
- pop %rcx # drop param1
- pop %rcx # drop param2
-
- #
- # restore CR4
- #
- movq %cr4, %rax
- bts $5, %eax
- movq %rax, %cr4
-
- #
- # restore CR3
- #
- movl %ebp, %eax
- movq %rax, %cr3
-
- #
- # Set EFER.LME to re-enable ia32-e
- #
- movl $0xC0000080, %ecx
- rdmsr
- bts $8, %eax
- wrmsr
- #
- # Enable paging
- #
- movq %cr0, %rax
- bts $31, %eax
- mov %rax, %cr0
-# Now we are in compatible mode
-
- #
- # Reload cs register
- #
- .byte 0xcb # retf
-ReloadCS:
- #
- # Now we're in Long Mode
- #
- #
- # Restore C register and eax hold the return status from 32-bit function.
- # Note: Do not touch rax from now which hold the return value from IA32 function
- #
- movl %ebx, %eax # put return status to EAX
- pop %rbx
- pop %rbp
- pop %rsi
- pop %rdi
- popfq
- #
- # Switch to orignal GDT and CS. here rsp is pointer to the orignal GDT descriptor.
- #
- lgdt (%rsp)
- #
- # drop GDT descriptor in stack
- #
- addq $0x10, %rsp
- #
- # switch to orignal CS and GDTR
- #
- pop %r9 # get CS
- shl $32, %r9 # rcx[32..47] <- Cs
- lea ReturnToLongMode(%rip), %rcx
- orq %r9, %rcx
- push %rcx
- .byte 0xcb # retf
-ReturnToLongMode:
- #
- # Reload original DS/ES/SS
- #
- pop %rcx
- movl %ecx, %ds
- movl %ecx, %es
- movl %ecx, %ss
-
- #
- # Restore IFLAG
- #
- popfq
-
- ret
-
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