1 files changed, 25 insertions, 0 deletions
diff --git a/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm b/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
new file mode 100644
index 0000000000..8547c30b81
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
@@ -0,0 +1,25 @@
+SECTION .text
+
+; INTN
+; EFIAPI
+; XenHypercall2 (
+;   IN     VOID *HypercallAddr,
+;   IN OUT INTN Arg1,
+;   IN OUT INTN Arg2
+;   );
+global ASM_PFX(XenHypercall2)
+ASM_PFX(XenHypercall2):
+  ; Save only ebx, ecx is supposed to be a scratch register and needs to be
+  ; saved by the caller
+  push ebx
+  ; Copy HypercallAddr to eax
+  mov eax, [esp + 8]
+  ; Copy Arg1 to the register expected by Xen
+  mov ebx, [esp + 12]
+  ; Copy Arg2 to the register expected by Xen
+  mov ecx, [esp + 16]
+  ; Call HypercallAddr
+  call eax
+  pop ebx
+  ret
+