1 files changed, 42 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseRiscVSbiLib/RiscVSbiEcall.S b/MdePkg/Library/BaseRiscVSbiLib/RiscVSbiEcall.S
new file mode 100644
index 0000000000..8ba69f8512
--- /dev/null
+++ b/MdePkg/Library/BaseRiscVSbiLib/RiscVSbiEcall.S
@@ -0,0 +1,42 @@
+//------------------------------------------------------------------------------
+//
+// Make ECALL to SBI
+//
+// Copyright (c) 2023, Ventana Micro Systems Inc. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+
+#include <Register/RiscV64/RiscVImpl.h>
+
+.data
+.align 3
+.section .text
+
+//
+// Make ECALL to SBI
+// ecall updates the same a0 and a1 registers with
+// return values. Hence, the C function which calls
+// this should pass the address of Arg0 and Arg1.
+// This routine saves the address and updates it
+// with a0 and a1 once ecall returns.
+//
+// @param a0 : Pointer to Arg0
+// @param a1 : Pointer to Arg1
+// @param a2 : Arg2
+// @param a3 : Arg3
+// @param a4 : Arg4
+// @param a5 : Arg5
+// @param a6 : FunctionID
+// @param a7 : ExtensionId
+//
+ASM_FUNC (RiscVSbiEcall)
+  mv t0, a0
+  mv t1, a1
+  ld a0, 0(a0)
+  ld a1, 0(a1)
+  ecall
+  sd a0, 0(t0)
+  sd a1, 0(t1)
+  ret