diff options
Diffstat (limited to 'UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionHandlerAsm.S')
| -rw-r--r-- | UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionHandlerAsm.S | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionHandlerAsm.S b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionHandlerAsm.S index 627f3e513c..3676809b4b 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionHandlerAsm.S +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionHandlerAsm.S @@ -1,6 +1,6 @@ #------------------------------------------------------------------------------
#*
-#* Copyright (c) 2012 - 2013, Intel Corporation. All rights reserved.<BR>
+#* Copyright (c) 2012 - 2015, 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
@@ -447,10 +447,25 @@ ErrorCodeAndVectorOnStack: pushl %eax
#; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4;
+## insure FXSAVE/FXRSTOR is enabled in CR4...
+## ... while we're at it, make sure DE is also enabled...
+ mov $1, %eax
+ pushl %ebx # temporarily save value of ebx on stack
+ cpuid # use CPUID to determine if FXSAVE/FXRESTOR
+ # and DE are supported
+ popl %ebx # retore value of ebx that was overwritten
+ # by CPUID
movl %cr4, %eax
- orl $0x208, %eax
+ pushl %eax # push cr4 firstly
+ testl $BIT24, %edx # Test for FXSAVE/FXRESTOR support
+ jz L1
+ orl $BIT9, %eax # Set CR4.OSFXSR
+L1:
+ testl $BIT2, %edx # Test for Debugging Extensions support
+ jz L2
+ orl $BIT3, %eax # Set CR4.DE
+L2:
movl %eax, %cr4
- pushl %eax
movl %cr3, %eax
pushl %eax
movl %cr2, %eax
@@ -477,7 +492,11 @@ ErrorCodeAndVectorOnStack: #; FX_SAVE_STATE_IA32 FxSaveState;
subl $512, %esp
movl %esp, %edi
+ testl $BIT24, %edx # Test for FXSAVE/FXRESTOR support.
+ # edx still contains result from CPUID above
+ jz L3
.byte 0x0f, 0x0ae, 0x07 #fxsave [edi]
+L3:
#; UEFI calling convention for IA32 requires that Direction flag in EFLAGs is clear
cld
@@ -503,7 +522,13 @@ ErrorCodeAndVectorOnStack: #; FX_SAVE_STATE_IA32 FxSaveState;
movl %esp, %esi
+ movl $1, %eax
+ cpuid # use CPUID to determine if FXSAVE/FXRESTOR
+ # are supported
+ testl $BIT24, %edx # Test for FXSAVE/FXRESTOR support
+ jz L4
.byte 0x0f, 0x0ae, 0x0e # fxrstor [esi]
+L4:
addl $512, %esp
#; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
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