MdePkg/BaseLib: Fix boot DxeCore hang on riscv platform

For scene of
HandOffToDxeCore()->SwitchStack(DxeCoreEntryPoint)->
InternalSwitchStack()->LongJump(),Variable HobList.Raw
will be passed (from *Context1 to register a0) to
DxeMain() in parameter *HobStart.

However, meanwhile the function LongJump() overrides
register a0 with a1 (-1)  due to commit (ea628f28e5 "RISCV: Fix
InternalLongJump to return correct value"), then cause hang.

Replacing calling LongJump() with new InternalSwitchStackAsm() to pass
addres data in register s0 to register a0 could fix this issue (just
like the solution in MdePkg/Library/BaseLib/AArch64/SwitchStack.S)

Signed-off-by: Yang Wang <wangyang@bosc.ac.cn>
Cc: Bamvor Jian ZHANG <zhangjian@bosc.ac.cn>
Cc: Andrei Warkentin <andrei.warkentin@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Sunil V L <sunilvl@ventanamicro.com>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Reviewed-by: Ran Wang <wangran@bosc.ac.cn>
Reviewed-by: Andrei Warkentin <andrei.warkentin@intel.com>

MdePkg/Library/BaseLib/BaseLib.inf

@@ -397,6 +397,7 @@
   RiscV64/CpuPause.c
   RiscV64/MemoryFence.S             | GCC
   RiscV64/RiscVSetJumpLongJump.S    | GCC
+  RiscV64/SwitchStack.S             | GCC
   RiscV64/RiscVCpuBreakpoint.S      | GCC
   RiscV64/RiscVCpuPause.S           | GCC
   RiscV64/RiscVInterrupt.S          | GCC

MdePkg/Library/BaseLib/RiscV64/InternalSwitchStack.c

@@ -8,6 +8,30 @@
 
 #include "BaseLibInternals.h"
 
+/**
+  Transfers control to a function starting with a new stack.
+
+  This internal worker function transfers control to the function
+  specified by EntryPoint using the new stack specified by NewStack,
+  and passes in the parameters specified by Context1 and Context2.
+  Context1 and Context2 are optional and may be NULL.
+  The function EntryPoint must never return.
+
+  @param Context1     The first parameter to pass in.
+  @param Context2     The second Parameter to pass in
+  @param EntryPoint   The pointer to the function to enter.
+  @param NewStack     The new Location of the stack
+
+**/
+VOID
+EFIAPI
+InternalSwitchStackAsm (
+  IN      VOID                      *Context1    OPTIONAL,
+  IN      VOID                      *Context2    OPTIONAL,
+  IN      SWITCH_STACK_ENTRY_POINT  EntryPoint,
+  IN      VOID                      *NewStack
+  );
+
 /**
   Transfers control to a function starting with a new stack.
 
@@ -42,12 +66,6 @@ InternalSwitchStack (
   IN      VA_LIST                   Marker
   )
 {
-  BASE_LIBRARY_JUMP_BUFFER  JumpBuffer;
-
-  JumpBuffer.RA = (UINTN)EntryPoint;
-  JumpBuffer.SP = (UINTN)NewStack - sizeof (VOID *);
-  JumpBuffer.S0 = (UINT64)(UINTN)Context1;
-  JumpBuffer.S1 = (UINT64)(UINTN)Context2;
-  LongJump (&JumpBuffer, (UINTN)-1);
+  InternalSwitchStackAsm (Context1, Context2, EntryPoint, (VOID *)((UINTN)NewStack - sizeof (VOID *)));
   ASSERT (FALSE);
 }

MdePkg/Library/BaseLib/RiscV64/SwitchStack.S

@@ -0,0 +1,37 @@
+//------------------------------------------------------------------------------
+//
+// InternalSwitchStackAsm for RISC-V
+//
+// Copyright (c) 2023, Bosc Corporation. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+.align 3
+
+#/**
+#
+# This allows the caller to switch the stack and goes to the new entry point
+#
+# @param      Context      Parameter to pass in
+# @param      Context2     Parameter2 to pass in
+# @param      EntryPoint   The pointer to the location to enter
+# @param      NewStack     New Location of the stack
+#
+# @return     Nothing. Goes to the Entry Point passing in the new parameters
+#
+#**/
+#VOID
+#EFIAPI
+#InternalSwitchStackAsm (
+#  VOID  *Context,
+#  VOID  *Context2,
+#  SWITCH_STACK_ENTRY_POINT EntryPoint,
+#  VOID  *NewStack
+#  );
+#
+    .globl InternalSwitchStackAsm
+InternalSwitchStackAsm:
+  mv ra, a2
+  mv sp, a3
+  ret