[edk2-staging/RISC-V-V2 PATCH v1 19/22]: MdeModulePkg/DxeIplPeim:RISC-V platform DXEIPL.

["Abner Chang" <abner.chang@hpe.com>]

- Implement RISC-V DxeIpl.
- Provide DxeIpl platform implementation-specifc library for RISC-V platform. Two libraries are provided in this commit,
  * Defualt library which simply switch stack and transfer
    control to DXE core.
  * Switch stack, privilege mode and then transfer control to
    DXE core through RISC-V opensbi.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Abner Chang <abner.chang@hpe.com>
---
 MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf            | 13 +++-
 MdeModulePkg/Core/DxeIplPeim/RiscV64/DxeLoadFunc.c | 76 ++++++++++++++++++++++
 2 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 MdeModulePkg/Core/DxeIplPeim/RiscV64/DxeLoadFunc.c

diff --git a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
index 98bc17f..5532323 100644
--- a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
+++ b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
@@ -7,6 +7,7 @@
 #
 #  Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
 #  Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
+#  Copyright (c) 2016 - 2019, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -25,7 +26,7 @@
 #
 # The following information is for reference only and not required by the build tools.
 #
-#  VALID_ARCHITECTURES           = IA32 X64 EBC (EBC is for build only) AARCH64
+#  VALID_ARCHITECTURES           = IA32 X64 EBC (EBC is for build only) AARCH64 RISCV64
 #
 
 [Sources]
@@ -49,6 +50,9 @@
 [Sources.ARM, Sources.AARCH64]
   Arm/DxeLoadFunc.c
 
+[Sources.RISCV64]
+  RiscV64/DxeLoadFunc.c
+
 [Packages]
   MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec
@@ -56,6 +60,9 @@
 [Packages.ARM, Packages.AARCH64]
   ArmPkg/ArmPkg.dec
 
+[Packages.RISCV64]
+  RiscVPkg/RiscVPkg.dec
+
 [LibraryClasses]
   PcdLib
   MemoryAllocationLib
@@ -75,6 +82,10 @@
 [LibraryClasses.ARM, LibraryClasses.AARCH64]
   ArmMmuLib
 
+[LibraryClasses.RISCV64]
+  RiscVPlatformDxeIplLib
+  RiscVOpensbiLib
+
 [Ppis]
   gEfiDxeIplPpiGuid                      ## PRODUCES
   gEfiPeiDecompressPpiGuid               ## PRODUCES
diff --git a/MdeModulePkg/Core/DxeIplPeim/RiscV64/DxeLoadFunc.c b/MdeModulePkg/Core/DxeIplPeim/RiscV64/DxeLoadFunc.c
new file mode 100644
index 0000000..934dfa5
--- /dev/null
+++ b/MdeModulePkg/Core/DxeIplPeim/RiscV64/DxeLoadFunc.c
@@ -0,0 +1,76 @@
+/** @file
+  RISC-V specific functionality for DxeLoad.
+
+  Copyright (c) 2016 - 2019, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution. The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+**/
+
+#include "DxeIpl.h"
+#include "Library/RiscVPlatformDxeIpl.h"
+
+typedef
+VOID*
+(EFIAPI *DXEENTRYPOINT) (
+  IN  VOID *HobStart
+  );
+
+/**
+   Transfers control to DxeCore.
+
+   This function performs a CPU architecture specific operations to execute
+   the entry point of DxeCore with the parameters of HobList.
+   It also installs EFI_END_OF_PEI_PPI to signal the end of PEI phase.
+
+   @param DxeCoreEntryPoint         The entry point of DxeCore.
+   @param HobList                   The start of HobList passed to DxeCore.
+
+**/
+VOID
+HandOffToDxeCore (
+  IN EFI_PHYSICAL_ADDRESS   DxeCoreEntryPoint,
+  IN EFI_PEI_HOB_POINTERS   HobList
+  )
+{
+  VOID                            *BaseOfStack;
+  VOID                            *TopOfStack;
+  EFI_STATUS                      Status;
+  //
+  //
+  // Allocate 128KB for the Stack
+  //
+  BaseOfStack = AllocatePages (EFI_SIZE_TO_PAGES (STACK_SIZE));
+  ASSERT (BaseOfStack != NULL);
+
+  //
+  // Compute the top of the stack we were allocated. Pre-allocate a UINTN
+  // for safety.
+  //
+  TopOfStack = (VOID *) ((UINTN) BaseOfStack + EFI_SIZE_TO_PAGES (STACK_SIZE) * EFI_PAGE_SIZE - CPU_STACK_ALIGNMENT);
+  TopOfStack = ALIGN_POINTER (TopOfStack, CPU_STACK_ALIGNMENT);
+
+  //
+  // End of PEI phase signal
+  //
+  Status = PeiServicesInstallPpi (&gEndOfPeiSignalPpi);
+  ASSERT_EFI_ERROR (Status);
+
+  //
+  // Update the contents of BSP stack HOB to reflect the real stack info passed to DxeCore.
+  //
+  UpdateStackHob ((EFI_PHYSICAL_ADDRESS)(UINTN) BaseOfStack, STACK_SIZE);
+
+  DEBUG ((EFI_D_INFO, "DXE Core new stack at %x, stack pointer at %x\n", BaseOfStack, TopOfStack));
+
+  //
+  // Transfer the control to the entry point of DxeCore.
+  //
+  RiscVPlatformHandOffToDxeCore (BaseOfStack, TopOfStack, DxeCoreEntryPoint, HobList);
+}
+
-- 
2.7.4