MdePkg/BaseLib: Preserve EBX register and fix stack offset to LinearAddress in AsmFlu...
authorMichael Kinney <michael.d.kinney@intel.com>
Thu, 30 Apr 2015 07:25:07 +0000 (07:25 +0000)
committererictian <erictian@Edk2>
Thu, 30 Apr 2015 07:25:07 +0000 (07:25 +0000)
commit6f7878a97281299bf4a052687a177dfbee4b0de1
treedb19b5da9e625f14db1ed88dd480d553c1df8fde
parent2bbe9553c495bb9024b4b51743142a0a50e0d370
MdePkg/BaseLib: Preserve EBX register and fix stack offset to LinearAddress in AsmFlushCacheLine()

The value of EBX must be preserved to follow IA32 cdecl calling convention in the assembly
implementation of AsmFlushCacheLine(). The CPUID instruction modifies the EBX register.
The EBX register value is saved onto the stack before CPUID and restored from the stack
after CPUID.

The update to the inline assembly implementation of AsmFlushCacheLine() changed the location of the
LinearAddress parameter value on the stack.  The hardcoded lookup using [esp + 4] is not correct.
Use the parameter name LinearAddress instead of the hard coded [esp + 4] stack location to prevent
this issue from occurring again if there are changes to the inline assembly in the future.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17279 6f19259b-4bc3-4df7-8a09-765794883524
MdePkg/Library/BaseLib/Ia32/FlushCacheLine.asm
MdePkg/Library/BaseLib/Ia32/FlushCacheLine.c