Move SmmDebug feature from ASM to C.

SmmDebug feature is implemented in ASM, which is not easy to maintain.
So we move it to C function.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: "Yao, Jiewen" <jiewen.yao@intel.com>
Reviewed-by: "Kinney, Michael D" <michael.d.kinney@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18946 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 28 insertions, 58 deletions

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.S b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.S
index 95e6dfa814..b488b74b70 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.S
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.S
@@ -24,7 +24,6 @@ ASM_GLOBAL  ASM_PFX(gcSmiHandlerSize)
 ASM_GLOBAL  ASM_PFX(gSmiCr3)

 ASM_GLOBAL  ASM_PFX(gSmiStack)

 ASM_GLOBAL  ASM_PFX(gSmbase)

-ASM_GLOBAL  ASM_PFX(FeaturePcdGet (PcdCpuSmmDebug))

 ASM_GLOBAL  ASM_PFX(gSmiHandlerIdtr)

 

 #

@@ -163,20 +162,7 @@ LongMode:                               # long mode (64-bit code) starts here
 #   jmp     _SmiHandler                 ; instruction is not needed

 

 _SmiHandler:

-    movabsq $ASM_PFX(FeaturePcdGet (PcdCpuSmmDebug)), %rax

-    cmpb    $0, (%rax)

-    jz      L1

-

-    .byte   0x48, 0x8b, 0x0d            # mov rcx, [rip + disp32]

-    .long   SSM_DR6 - (. + 4 - _SmiEntryPoint + 0x8000)

-    .byte   0x48, 0x8b, 0x15            # mov rdx, [rip + disp32]

-    .long   SSM_DR7 - (. + 4 - _SmiEntryPoint + 0x8000)

-    movq    %rcx, %dr6

-    movq    %rdx, %dr7

-L1:

-

-    movabsq $ASM_PFX(SmiRendezvous), %rax

-    movq    (%rsp), %rcx

+    movq    (%rsp), %rbx

     # Save FP registers

 

     subq    $0x208, %rsp

@@ -184,7 +170,19 @@ L1:
     fxsave  (%rsp)

 

     addq    $-0x20, %rsp

+

+    movq    %rbx, %rcx

+    movabsq $ASM_PFX(CpuSmmDebugEntry), %rax

     call    *%rax

+

+    movq    %rbx, %rcx

+    movabsq $ASM_PFX(SmiRendezvous), %rax

+    call    *%rax

+

+    movq    %rbx, %rcx

+    movabsq $ASM_PFX(CpuSmmDebugExit), %rax

+    call    *%rax

+

     addq    $0x20, %rsp

 

     #

@@ -193,17 +191,6 @@ L1:
     .byte   0x48                        # FXRSTOR64

     fxrstor (%rsp)

 

-    movabsq $ASM_PFX(FeaturePcdGet (PcdCpuSmmDebug)), %rax

-    cmpb    $0, (%rax)

-    jz      L2

-

-    movq    %dr7, %rdx

-    movq    %dr6, %rcx

-    .byte   0x48, 0x89, 0x15            # mov [rip + disp32], rdx

-    .long   SSM_DR7 - (. + 4 - _SmiEntryPoint + 0x8000)

-    .byte   0x48, 0x89, 0x0d            # mov [rip + disp32], rcx

-    .long   SSM_DR6 - (. + 4 - _SmiEntryPoint + 0x8000)

-L2:

     rsm

 

 ASM_PFX(gcSmiHandlerSize):    .word      . - _SmiEntryPoint

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.asm b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.asm
index 4d53db5b00..4f5c03c5cf 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.asm
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.asm
@@ -22,12 +22,13 @@
 ; Variables referenced by C code

 ;

 EXTERNDEF   SmiRendezvous:PROC

+EXTERNDEF   CpuSmmDebugEntry:PROC

+EXTERNDEF   CpuSmmDebugExit:PROC

 EXTERNDEF   gcSmiHandlerTemplate:BYTE

 EXTERNDEF   gcSmiHandlerSize:WORD

 EXTERNDEF   gSmiCr3:DWORD

 EXTERNDEF   gSmiStack:DWORD

 EXTERNDEF   gSmbase:DWORD

-EXTERNDEF   FeaturePcdGet (PcdCpuSmmDebug):BYTE

 EXTERNDEF   gSmiHandlerIdtr:FWORD

 

 

@@ -157,26 +158,7 @@ Base:
 ;   jmp     _SmiHandler                 ; instruction is not needed

 

 _SmiHandler:

-;

-; The following lines restore DR6 & DR7 before running C code. They are useful

-; when you want to enable hardware breakpoints in SMM.

-;

-; NOTE: These lines might not be appreciated in runtime since they might

-;       conflict with OS debugging facilities. Turn them off in RELEASE.

-;

-    mov     rax, offset FeaturePcdGet (PcdCpuSmmDebug) ;Get absolute address. Avoid RIP relative addressing

-    cmp     byte ptr [rax], 0

-    jz      @1

-

-    DB      48h, 8bh, 0dh               ; mov rcx, [rip + disp32]

-    DD      SSM_DR6 - ($ + 4 - _SmiEntryPoint + 8000h)

-    DB      48h, 8bh, 15h               ; mov rdx, [rip + disp32]

-    DD      SSM_DR7 - ($ + 4 - _SmiEntryPoint + 8000h)

-    mov     dr6, rcx

-    mov     dr7, rdx

-@1:

-    mov     rcx, [rsp]                  ; rcx <- CpuIndex

-    mov     rax, SmiRendezvous          ; rax <- absolute addr of SmiRedezvous

+    mov     rbx, [rsp]                  ; rbx <- CpuIndex

 

     ;

     ; Save FP registers

@@ -186,7 +168,19 @@ _SmiHandler:
     fxsave  [rsp]

 

     add     rsp, -20h

+

+    mov     rcx, rbx

+    mov     rax, CpuSmmDebugEntry

+    call    rax

+    

+    mov     rcx, rbx

+    mov     rax, SmiRendezvous          ; rax <- absolute addr of SmiRedezvous

+    call    rax

+    

+    mov     rcx, rbx

+    mov     rax, CpuSmmDebugExit

     call    rax

+    

     add     rsp, 20h

 

     ;

@@ -195,17 +189,6 @@ _SmiHandler:
     DB      48h                         ; FXRSTOR64

     fxrstor [rsp]

 

-    mov     rax, offset FeaturePcdGet (PcdCpuSmmDebug) ;Get absolute address. Avoid RIP relative addressing

-    cmp     byte ptr [rax], 0

-    jz      @2

-

-    mov     rdx, dr7

-    mov     rcx, dr6

-    DB      48h, 89h, 15h               ; mov [rip + disp32], rdx

-    DD      SSM_DR7 - ($ + 4 - _SmiEntryPoint + 8000h)

-    DB      48h, 89h, 0dh               ; mov [rip + disp32], rcx

-    DD      SSM_DR6 - ($ + 4 - _SmiEntryPoint + 8000h)

-@2:

     rsm

 

 gcSmiHandlerSize    DW      $ - _SmiEntryPoint