diff options
Diffstat (limited to 'OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.S')
| -rw-r--r-- | OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.S | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.S b/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.S new file mode 100644 index 0000000000..58dfa8ba57 --- /dev/null +++ b/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.S @@ -0,0 +1,13 @@ +# INT32
+# EFIAPI
+# TestAndClearBit (
+# IN INT32 Bit,
+# IN volatile VOID* Address
+# );
+ASM_GLOBAL ASM_PFX(TestAndClearBit)
+ASM_PFX(TestAndClearBit):
+ mov 4(%esp), %ecx
+ mov 8(%esp), %edx
+ lock btrl %ecx, (%edx)
+ sbbl %eax, %eax
+ ret
|