diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
index 314143b294..9e0b54ec78 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
@@ -47,6 +47,9 @@
LoongArch/LoongArch64/ExceptionHandlerAsm.S | GCC
[Sources.RISCV64]
+ RiscV/Backtrace.h
+ RiscV/Backtrace.c
+ RiscV/BacktraceHelper.c
RiscV/ExceptionLib.c
RiscV/ExceptionHandler.h
RiscV/ExceptionHandlerAsm.S | GCC
@@ -80,5 +83,8 @@
[LibraryClasses.LoongArch64]
CpuLib
+[Guids.RISCV64]
+ gEfiDebugImageInfoTableGuid
+
[BuildOptions]
XCODE:*_*_X64_NASM_FLAGS = -D NO_ABSOLUTE_RELOCS_IN_TEXT
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/Backtrace.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/Backtrace.c
new file mode 100644
index 0000000000..9765d721e5
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/Backtrace.c
@@ -0,0 +1,175 @@
+/** @file
+ RISC-V backtrace implementation.
+
+ Copyright (c) 2016 - 2022, Hewlett Packard Enterprise Development LP. All rights reserved.
+ Copyright (c) 2011 - 2014, ARM Ltd. All rights reserved.
+ Copyright (c) 2023, Intel Corporation. All rights reserved.
+ Copyright (c) 2025, Ventana Micro Systems Inc. All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "Backtrace.h"
+
+#define MAX_STACK_FRAME_SIZE SIZE_16KB
+
+STATIC
+INTN
+CheckFpValid (
+ IN UINTN Fp,
+ IN UINTN Sp
+ )
+{
+ UINTN Low, High;
+
+ Low = Sp + 2 * sizeof (UINTN);
+ High = ALIGN_VALUE (Sp, MAX_STACK_FRAME_SIZE);
+
+ return !(Fp < Low || Fp > High || Fp & 0x07);
+}
+
+STATIC
+CONST CHAR8 *
+BaseName (
+ IN CONST CHAR8 *FullName
+ )
+{
+ CONST CHAR8 *Str;
+
+ Str = FullName + AsciiStrLen (FullName);
+
+ while (--Str > FullName) {
+ if ((*Str == '/') || (*Str == '\\')) {
+ return Str + 1;
+ }
+ }
+
+ return Str;
+}
+
+/**
+ Helper for displaying a backtrace.
+
+ @param Regs Pointer to SMODE_TRAP_REGISTERS.
+ @param FirstPdb Pointer to the first symbol file used.
+ @param ListImage If true, only show the full path to symbol file, else
+ show the PC value and its decoded components.
+**/
+STATIC
+VOID
+DumpCpuBacktraceHelper (
+ IN SMODE_TRAP_REGISTERS *Regs,
+ IN CHAR8 *FirstPdb,
+ IN BOOLEAN ListImage
+ )
+{
+ UINTN ImageBase;
+ UINTN PeCoffSizeOfHeader;
+ BOOLEAN IsLeaf;
+ UINTN RootFp;
+ UINTN RootRa;
+ UINTN Sp;
+ UINTN Fp;
+ UINTN Ra;
+ UINTN Idx;
+ CHAR8 *Pdb;
+ CHAR8 *PrevPdb;
+
+ RootRa = Regs->ra;
+ RootFp = Regs->s0;
+
+ Idx = 0;
+ IsLeaf = TRUE;
+ Fp = RootFp;
+ Ra = RootRa;
+ PrevPdb = FirstPdb;
+ while (Fp != 0) {
+ Pdb = GetImageName (Ra, &ImageBase, &PeCoffSizeOfHeader);
+ if (Pdb != NULL) {
+ if (Pdb != PrevPdb) {
+ Idx++;
+ if (ListImage) {
+ DEBUG ((DEBUG_ERROR, "[% 2d] %a\n", Idx, Pdb));
+ }
+
+ PrevPdb = Pdb;
+ }
+
+ if (!ListImage) {
+ DEBUG ((
+ DEBUG_ERROR,
+ "PC 0x%012lx (0x%012lx+0x%08x) [% 2d] %a\n",
+ Ra,
+ ImageBase,
+ Ra - ImageBase,
+ Idx,
+ BaseName (Pdb)
+ ));
+ }
+ } else if (!ListImage) {
+ DEBUG ((DEBUG_ERROR, "PC 0x%012lx\n", Ra));
+ }
+
+ /*
+ * After the prologue, the frame pointer register s0 will point
+ * to the Canonical Frame Address or CFA, which is the stack
+ * pointer value on entry to the current procedure. The previous
+ * frame pointer and return address pair will reside just prior
+ * to the current stack address held in s0. This puts the return
+ * address at s0 - XLEN/8, and the previous frame pointer at
+ * s0 - 2 * XLEN/8.
+ */
+ Sp = Fp;
+ Fp -= sizeof (UINTN) * 2;
+ Ra = *(UINTN *)(Fp + sizeof (UINTN));
+ Fp = *(UINTN *)(Fp);
+ if (IsLeaf && CheckFpValid (Ra, Sp)) {
+ /* We hit function where ra is not saved on the stack */
+ Fp = Ra;
+ Ra = RootRa;
+ }
+
+ IsLeaf = FALSE;
+ }
+}
+
+/**
+ Display a backtrace.
+
+ @param SystemContext Pointer to EFI_SYSTEM_CONTEXT.
+**/
+VOID
+EFIAPI
+DumpCpuBacktrace (
+ IN EFI_SYSTEM_CONTEXT SystemContext
+ )
+{
+ SMODE_TRAP_REGISTERS *Regs;
+ CHAR8 *Pdb;
+ UINTN ImageBase;
+ UINTN PeCoffSizeOfHeader;
+
+ Regs = (SMODE_TRAP_REGISTERS *)SystemContext.SystemContextRiscV64;
+ Pdb = GetImageName (Regs->sepc, &ImageBase, &PeCoffSizeOfHeader);
+ if (Pdb != NULL) {
+ DEBUG ((
+ DEBUG_ERROR,
+ "PC 0x%012lx (0x%012lx+0x%08x) [ 0] %a\n",
+ Regs->sepc,
+ ImageBase,
+ Regs->sepc - ImageBase,
+ BaseName (Pdb)
+ ));
+ } else {
+ DEBUG ((DEBUG_ERROR, "PC 0x%012lx\n", Regs->sepc));
+ }
+
+ DumpCpuBacktraceHelper (Regs, Pdb, FALSE);
+
+ if (Pdb != NULL) {
+ DEBUG ((DEBUG_ERROR, "\n[ 0] %a\n", Pdb));
+ }
+
+ DumpCpuBacktraceHelper (Regs, Pdb, TRUE);
+}
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/Backtrace.h b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/Backtrace.h
new file mode 100644
index 0000000000..6e29b9080f
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/Backtrace.h
@@ -0,0 +1,57 @@
+/** @file
+
+ RISC-V backtrace definition file.
+
+ Copyright (c) 2025, Ventana Micro Systems Inc. All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef BACKTRACE_H_
+#define BACKTRACE_H_
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include "ExceptionHandler.h"
+
+/**
+ Use the EFI Debug Image Table to lookup the FaultAddress and find which PE/COFF image
+ it came from. As long as the PE/COFF image contains a debug directory entry a
+ string can be returned. For ELF and Mach-O images the string points to the Mach-O or ELF
+ image. Microsoft tools contain a pointer to the PDB file that contains the debug information.
+
+ @param FaultAddress Address to find PE/COFF image for.
+ @param ImageBase Return load address of found image
+ @param PeCoffSizeOfHeaders Return the size of the PE/COFF header for the image that was found
+
+ @retval NULL FaultAddress not in a loaded PE/COFF image.
+ @retval Path and file name of PE/COFF image.
+
+**/
+CHAR8 *
+EFIAPI
+GetImageName (
+ IN UINTN FaultAddress,
+ OUT UINTN *ImageBase,
+ OUT UINTN *PeCoffSizeOfHeaders
+ );
+
+/**
+ Display a backtrace.
+
+ @param SystemContext Pointer to EFI_SYSTEM_CONTEXT.
+**/
+VOID
+EFIAPI
+DumpCpuBacktrace (
+ IN EFI_SYSTEM_CONTEXT SystemContext
+ );
+
+#endif // BACKTRACE_H_
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/BacktraceHelper.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/BacktraceHelper.c
new file mode 100644
index 0000000000..fdc56669ae
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/BacktraceHelper.c
@@ -0,0 +1,71 @@
+/** @file
+ RISC-V backtrace helper functions.
+
+ Copyright (c) 2016 - 2022, Hewlett Packard Enterprise Development LP. All rights reserved.
+ Copyright (c) 2011 - 2014, ARM Ltd. All rights reserved.
+ Copyright (c) 2023, Intel Corporation. All rights reserved.
+ Copyright (c) 2025, Ventana Micro Systems Inc. All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "Backtrace.h"
+
+/**
+ Use the EFI Debug Image Table to lookup the FaultAddress and find which PE/COFF image
+ it came from. As long as the PE/COFF image contains a debug directory entry a
+ string can be returned. For ELF and Mach-O images the string points to the Mach-O or ELF
+ image. Microsoft tools contain a pointer to the PDB file that contains the debug information.
+
+ @param FaultAddress Address to find PE/COFF image for.
+ @param ImageBase Return load address of found image
+ @param PeCoffSizeOfHeaders Return the size of the PE/COFF header for the image that was found
+
+ @retval NULL FaultAddress not in a loaded PE/COFF image.
+ @retval Path and file name of PE/COFF image.
+
+**/
+CHAR8 *
+EFIAPI
+GetImageName (
+ IN UINTN FaultAddress,
+ OUT UINTN *ImageBase,
+ OUT UINTN *PeCoffSizeOfHeaders
+ )
+{
+ EFI_STATUS Status;
+ EFI_DEBUG_IMAGE_INFO_TABLE_HEADER *DebugTableHeader;
+ EFI_DEBUG_IMAGE_INFO *DebugTable;
+ UINTN Entry;
+ CHAR8 *Address;
+
+ Status = EfiGetSystemConfigurationTable (&gEfiDebugImageInfoTableGuid, (VOID **)&DebugTableHeader);
+ if (EFI_ERROR (Status)) {
+ return NULL;
+ }
+
+ DebugTable = DebugTableHeader->EfiDebugImageInfoTable;
+ if (DebugTable == NULL) {
+ return NULL;
+ }
+
+ Address = (CHAR8 *)(UINTN)FaultAddress;
+ for (Entry = 0; Entry < DebugTableHeader->TableSize; Entry++, DebugTable++) {
+ if (DebugTable->NormalImage != NULL) {
+ if ((DebugTable->NormalImage->ImageInfoType == EFI_DEBUG_IMAGE_INFO_TYPE_NORMAL) &&
+ (DebugTable->NormalImage->LoadedImageProtocolInstance != NULL))
+ {
+ if ((Address >= (CHAR8 *)DebugTable->NormalImage->LoadedImageProtocolInstance->ImageBase) &&
+ (Address <= ((CHAR8 *)DebugTable->NormalImage->LoadedImageProtocolInstance->ImageBase + DebugTable->NormalImage->LoadedImageProtocolInstance->ImageSize)))
+ {
+ *ImageBase = (UINTN)DebugTable->NormalImage->LoadedImageProtocolInstance->ImageBase;
+ *PeCoffSizeOfHeaders = PeCoffGetSizeOfHeaders ((VOID *)(UINTN)*ImageBase);
+ return PeCoffLoaderGetPdbPointer (DebugTable->NormalImage->LoadedImageProtocolInstance->ImageBase);
+ }
+ }
+ }
+ }
+
+ return NULL;
+}
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/BacktraceHelperSec.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/BacktraceHelperSec.c
new file mode 100644
index 0000000000..10e3497bfe
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/BacktraceHelperSec.c
@@ -0,0 +1,42 @@
+/** @file
+ RISC-V backtrace helper functions for SEC.
+
+ Copyright (c) 2025, Ventana Micro Systems Inc. All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "Backtrace.h"
+
+/**
+ Use the EFI Debug Image Table to lookup the FaultAddress and find which PE/COFF image
+ it came from. As long as the PE/COFF image contains a debug directory entry a
+ string can be returned. For ELF and Mach-O images the string points to the Mach-O or ELF
+ image. Microsoft tools contain a pointer to the PDB file that contains the debug information.
+
+ @param FaultAddress Address to find PE/COFF image for.
+ @param ImageBase Return load address of found image
+ @param PeCoffSizeOfHeaders Return the size of the PE/COFF header for the image that was found
+
+ @retval NULL FaultAddress not in a loaded PE/COFF image.
+ @retval Path and file name of PE/COFF image.
+
+**/
+CHAR8 *
+EFIAPI
+GetImageName (
+ IN UINTN FaultAddress,
+ OUT UINTN *ImageBase,
+ OUT UINTN *PeCoffSizeOfHeaders
+ )
+{
+ //
+ // This function is not implemented in SEC phase.
+ // It should be implemented in DXE phase.
+ //
+ *ImageBase = 0;
+ *PeCoffSizeOfHeaders = 0;
+
+ return NULL;
+}
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/ExceptionLib.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/ExceptionLib.c
index 48f57f6c5a..d19c99234d 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/ExceptionLib.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/RiscV/ExceptionLib.c
@@ -2,6 +2,9 @@
RISC-V Exception Handler library implementation.
Copyright (c) 2016 - 2022, Hewlett Packard Enterprise Development LP. All rights reserved.
+ Copyright (c) 2011 - 2014, ARM Ltd. All rights reserved.
+ Copyright (c) 2023, Intel Corporation. All rights reserved.
+ Copyright (c) 2025, Ventana Micro Systems Inc. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -14,6 +17,7 @@
#include
#include
#include
+#include "Backtrace.h"
#include "ExceptionHandler.h"
//
@@ -136,11 +140,21 @@ DumpCpuContext (
)
{
UINTN Printed;
+ UINTN RecursiveException;
SMODE_TRAP_REGISTERS *Regs;
Printed = 0;
Regs = (SMODE_TRAP_REGISTERS *)SystemContext.SystemContextRiscV64;
+ RecursiveException = RiscVGetSupervisorScratch ();
+ if (RecursiveException == 0xdeaddead) {
+ InternalPrintMessage ("\nRecursive exception occurred while dumping the CPU state\n");
+
+ CpuDeadLoop ();
+ }
+
+ RiscVSetSupervisorScratch ((UINTN)0xdeaddead);
+
InternalPrintMessage (
"!!!! RISCV64 Exception Type - %016x(%a) !!!!\n",
ExceptionType,
@@ -171,6 +185,8 @@ DumpCpuContext (
#undef REG
#undef REGS
+ DumpCpuBacktrace (SystemContext);
+
DEBUG_CODE_END ();
}
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
index cc872e12b0..00a5b495e0 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
@@ -47,6 +47,9 @@
LoongArch/LoongArch64/ExceptionHandlerAsm.S | GCC
[Sources.RISCV64]
+ RiscV/Backtrace.h
+ RiscV/Backtrace.c
+ RiscV/BacktraceHelperSec.c
RiscV/ExceptionLib.c
RiscV/ExceptionHandler.h
RiscV/ExceptionHandlerAsm.S | GCC