audk/OvmfPkg/XenBusDxe/X64/TestAndClearBit.nasm

16 lines
270 B
NASM

DEFAULT REL
SECTION .text
; INT32
; EFIAPI
; TestAndClearBit (
; IN INT32 Bit, // rcx
; IN volatile VOID* Address // rdx
; );
global ASM_PFX(TestAndClearBit)
ASM_PFX(TestAndClearBit):
lock btr [rdx], ecx
sbb eax, eax
ret