diff options
Diffstat (limited to 'OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm')
| -rw-r--r-- | OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm b/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm new file mode 100644 index 0000000000..d77f74ef24 --- /dev/null +++ b/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm @@ -0,0 +1,16 @@ +SECTION .text
+
+; INT32
+; EFIAPI
+; TestAndClearBit (
+; IN INT32 Bit,
+; IN volatile VOID* Address
+; );
+global ASM_PFX(TestAndClearBit)
+ASM_PFX(TestAndClearBit):
+ mov ecx, [esp + 4]
+ mov edx, [esp + 8]
+ lock btr [edx], ecx
+ sbb eax, eax
+ ret
+
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