UefiCpuPkg/SmmCpuFeaturesLib: replace hard-coded machine code

Replace hard-coded machine code with equivalent assembly source code.
Changes tested by checking for machine code equivalence by disassembling
the original and changed code.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chris Ruffin <chris.ruffin@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>

2 files changed, 16 insertions, 13 deletions

diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmiEntry.nasm b/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmiEntry.nasm
index b1c84a494f..00c0f0672c 100644
--- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmiEntry.nasm
+++ b/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmiEntry.nasm
@@ -1,5 +1,5 @@
 ;------------------------------------------------------------------------------ ;

-; Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>

+; Copyright (c) 2016 - 2017, 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

@@ -51,6 +51,11 @@ global ASM_PFX(gStmSmbase)
 global ASM_PFX(gStmXdSupported)

 extern ASM_PFX(gStmSmiHandlerIdtr)

 

+ASM_PFX(gStmSmiCr3)      EQU StmSmiCr3Patch - 4

+ASM_PFX(gStmSmiStack)    EQU StmSmiStackPatch - 4

+ASM_PFX(gStmSmbase)      EQU StmSmbasePatch - 4

+ASM_PFX(gStmXdSupported) EQU StmXdSupportedPatch - 1

+

     SECTION .text

 

 BITS 16

@@ -66,8 +71,8 @@ _StmSmiEntryPoint:
 o32 lgdt    [cs:bx]                       ; lgdt fword ptr cs:[bx]

     mov     ax, PROTECT_MODE_CS

     mov     [cs:bx-0x2],ax

-    DB      0x66, 0xbf                   ; mov edi, SMBASE

-ASM_PFX(gStmSmbase): DD 0

+o32 mov     edi, strict dword 0

+StmSmbasePatch:

     lea     eax, [edi + (@32bit - _StmSmiEntryPoint) + 0x8000]

     mov     [cs:bx-0x6],eax

     mov     ebx, cr0

@@ -87,15 +92,15 @@ o16 mov     es, ax
 o16 mov     fs, ax

 o16 mov     gs, ax

 o16 mov     ss, ax

-    DB      0xbc                   ; mov esp, imm32

-ASM_PFX(gStmSmiStack): DD 0

+    mov     esp, strict dword 0

+StmSmiStackPatch:

     mov     eax, ASM_PFX(gStmSmiHandlerIdtr)

     lidt    [eax]

     jmp     ProtFlatMode

 

 ProtFlatMode:

-    DB      0xb8                        ; mov eax, imm32

-ASM_PFX(gStmSmiCr3): DD 0

+    mov eax, strict dword 0

+StmSmiCr3Patch:

     mov     cr3, eax

 ;

 ; Need to test for CR4 specific bit support

@@ -134,8 +139,8 @@ ASM_PFX(gStmSmiCr3): DD 0
 .6:

 

 ; enable NXE if supported

-    DB      0b0h                        ; mov al, imm8

-ASM_PFX(gStmXdSupported):     DB      1

+    mov     al, strict byte 1

+StmXdSupportedPatch:

     cmp     al, 0

     jz      @SkipXd

 ;

@@ -268,4 +273,3 @@ _StmSmiHandler:
 

 ASM_PFX(gcStmSmiHandlerSize)   : DW        $ - _StmSmiEntryPoint

 ASM_PFX(gcStmSmiHandlerOffset) : DW        _StmSmiHandler - _StmSmiEntryPoint

-

diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmiException.nasm b/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmiException.nasm
index 0ce8501ba9..93dc3005b7 100644
--- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmiException.nasm
+++ b/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmiException.nasm
@@ -1,5 +1,5 @@
 ;------------------------------------------------------------------------------ ;

-; Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>

+; Copyright (c) 2009 - 2017, 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

@@ -87,7 +87,7 @@ ASM_PFX(OnException):
 

     mov  ebx, eax

     mov  eax, 4

-    DB  0x0f, 0x01, 0x0c1 ; VMCALL

+    vmcall

     jmp $

 

 global ASM_PFX(OnStmSetup)

@@ -173,4 +173,3 @@ ASM_PFX(OnStmTeardown):
 

 .72:

   rsm

-