SourceLevelDebugPkg/DebugAgent: Support IA32 processors without DE or FXSAVE/FXRESTOR

[mirror_edk2.git] / SourceLevelDebugPkg / Library / DebugAgent / DebugAgentCommon / Ia32 / AsmFuncs.asm

diff --git a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/Ia32/AsmFuncs.asm b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/Ia32/AsmFuncs.asm
index 377ade7c3b3ed1aae423e5c092e7a9388d4dcae9..44ed6f77102a54a360f3747e8b6679ca0dc61b84 100644 (file)
--- a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/Ia32/AsmFuncs.asm
+++ b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/Ia32/AsmFuncs.asm
@@ -230,9 +230,21 @@ NoExtrPush:
     ;; UINT32  Cr0, Cr1, Cr2, Cr3, Cr4;\r
     ;; insure FXSAVE/FXRSTOR is enabled in CR4...\r
     ;; ... while we're at it, make sure DE is also enabled...\r
+    mov     eax, 1\r
+    push    ebx         ; temporarily save value of ebx on stack \r
+    cpuid               ; use CPUID to determine if FXSAVE/FXRESTOR and\r
+                        ; DE are supported\r
+    pop     ebx         ; retore value of ebx that was overwritten by CPUID \r
     mov     eax, cr4\r
-    push    eax       ; push cr4 firstly\r
-    or      eax, 208h\r
+    push    eax         ; push cr4 firstly\r
+    test    edx, BIT24  ; Test for FXSAVE/FXRESTOR support\r
+    jz      @F\r
+    or      eax, BIT9   ; Set CR4.OSFXSR\r
+@@:    \r
+    test    edx, BIT2   ; Test for Debugging Extensions support\r
+    jz      @F\r
+    or      eax, BIT3   ; Set CR4.DE\r
+@@:    \r
     mov     cr4, eax\r
     mov     eax, cr3\r
     push    eax\r
@@ -313,7 +325,12 @@ NoExtrPush:
     mov     ecx, 128 ;= 512 / 4\r
     rep     stosd\r
     mov     edi, esp\r
+\r
+    test    edx, BIT24  ; Test for FXSAVE/FXRESTOR support.\r
+                        ; edx still contains result from CPUID above\r
+    jz      @F\r
     db 0fh, 0aeh, 00000111y ;fxsave [edi]\r
+@@:    \r
 \r
     ;; save the exception data\r
     push    dword ptr [ebp + 8]\r
@@ -329,7 +346,12 @@ NoExtrPush:
 \r
     ;; FX_SAVE_STATE_IA32 FxSaveState;\r
     mov     esi, esp\r
+    mov     eax, 1\r
+    cpuid               ; use CPUID to determine if FXSAVE/FXRESTOR are supported\r
+    test    edx, BIT24  ; Test for FXSAVE/FXRESTOR support\r
+    jz      @F\r
     db 0fh, 0aeh, 00001110y ; fxrstor [esi]\r
+@@:    \r
     add esp, 512\r
 \r
     ;; UINT32  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;\r