OvmfPkg/XenBusDxe/Ia32/hypercall.asm

   1 .code
   2
   3 ; INTN
   4 ; EFIAPI
   5 ; XenHypercall2 (
   6 ;   IN     VOID *HypercallAddr,
   7 ;   IN OUT INTN Arg1,
   8 ;   IN OUT INTN Arg2
   9 ;   );
  10 XenHypercall2 PROC
  11   ; Save only ebx, ecx is supposed to be a scratch register and needs to be
  12   ; saved by the caller
  13   push ebx
  14   ; Copy HypercallAddr to eax
  15   mov eax, [esp + 8]
  16   ; Copy Arg1 to the register expected by Xen
  17   mov ebx, [esp + 12]
  18   ; Copy Arg2 to the register expected by Xen
  19   mov ecx, [esp + 16]
  20   ; Call HypercallAddr
  21   call eax
  22   pop ebx
  23   ret
  24 XenHypercall2 ENDP
  25
  26 END