diff -ur --new-file protobuf-2.5.0/src/google/protobuf/stubs/atomicops.h protobuf-2.5.0/src/google/protobuf/stubs/atomicops.h
--- protobuf-2.5.0/src/google/protobuf/stubs/atomicops.h	2023-07-27 21:16:40.005186825 +0800
+++ protobuf-2.5.0/src/google/protobuf/stubs/atomicops.h	2023-07-27 21:24:31.862046665 +0800
@@ -184,6 +184,8 @@
 #include <google/protobuf/stubs/atomicops_internals_mips_gcc.h>
 #elif defined(__pnacl__)
 #include <google/protobuf/stubs/atomicops_internals_pnacl.h>
+#elif defined(GOOGLE_PROTOBUF_ARCH_RISCV64)
+#include <google/protobuf/stubs/atomicops_internals_riscv64_gcc.h>
 #else
 #include <google/protobuf/stubs/atomicops_internals_generic_gcc.h>
 #endif
diff -ur --new-file protobuf-2.5.0/src/google/protobuf/stubs/atomicops_internals_riscv64_gcc.h protobuf-2.5.0/src/google/protobuf/stubs/atomicops_internals_riscv64_gcc.h
--- protobuf-2.5.0/src/google/protobuf/stubs/atomicops_internals_riscv64_gcc.h	1970-01-01 08:00:00.000000000 +0800
+++ protobuf-2.5.0/src/google/protobuf/stubs/atomicops_internals_riscv64_gcc.h	2023-07-27 21:27:17.770362136 +0800
@@ -0,0 +1,295 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2012 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// This file is an internal atomic implementation, use atomicops.h instead.
+
+#ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_RISCV64_GCC_H_
+#define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_RISCV64_GCC_H_
+
+#define ATOMICOPS_COMPILER_BARRIER() __asm__ __volatile__("" : : : "memory")
+
+namespace google {
+namespace protobuf {
+namespace internal {
+
+// Atomically execute:
+//      result = *ptr;
+//      if (*ptr == old_value)
+//        *ptr = new_value;
+//      return result;
+//
+// I.e., replace "*ptr" with "new_value" if "*ptr" used to be "old_value".
+// Always return the old value of "*ptr"
+//
+// This routine implies no memory barriers.
+inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
+                                         Atomic32 old_value,
+                                         Atomic32 new_value) {
+  Atomic32 prev, tmp;
+  Atomic32 check;
+  __asm__ __volatile__(
+                       "1:\n"
+                       "lr.w %0, (%5)\n"  // prev = *ptr
+                       "bne %0, %3, 2f\n"  // if (prev != old_value) goto 2
+	  	  	   	   	   "move %1, %4\n"  // tmp = new_value
+                       "sc.w %2, %1, (%5)\n"  // *ptr = tmp (with atomic check)
+                       "bnez %2, 1b\n"  // start again on atomic error
+                       "nop\n"  // delay slot nop
+                       "2:\n"
+                       : "=&r" (prev), "=&r" (tmp), "=&r"(check)
+                       : "r" (old_value), "r" (new_value), "r" (ptr)
+                       : "memory");
+  return prev;
+}
+
+inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
+                                         Atomic64 old_value,
+                                         Atomic64 new_value) {
+  Atomic64 prev, tmp;
+  Atomic64 check;
+  __asm__ __volatile__(
+		  	  	  	   "1:\n"
+                       "lr.d %0, (%5)\n"  // prev = *ptr
+                       "bne %0, %3, 2f\n"  // if (prev != old_value) goto 2
+	  	  	   	   	   "move %1, %4\n"  // tmp = new_value
+                       "sc.d %2, %1, (%5)\n"  // *ptr = tmp (with atomic check)
+                       "bnez %2, 1b\n"  // start again on atomic error
+                       "nop\n"  // delay slot nop
+                       "2:\n"
+                       : "=&r" (prev), "=&r" (tmp), "=&r"(check)
+                       : "r" (old_value), "r" (new_value), "r" (ptr)
+                       : "memory");
+  return prev;
+}
+
+// Atomically store new_value into *ptr, returning the previous value held in
+// *ptr.  This routine implies no memory barriers.
+inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr,
+                                         Atomic32 new_value) {
+  Atomic32 temp, old;
+  Atomic32 check;
+  __asm__ __volatile__(
+                       "1:\n"
+                       "lr.w %1, (%4)\n"  // old = *ptr
+                       "move %0, %3\n"  // temp = new_value
+                       "sc.w %2, %0, (%4)\n"  // *ptr = temp (with atomic check)
+                       "bnez %2, 1b\n"  // start again on atomic error
+                       "nop\n"  // delay slot nop
+                       : "=&r" (temp), "=&r" (old), "=&r"(check)
+                       : "r" (new_value), "r" (ptr)
+                       : "memory");
+
+  return old;
+}
+
+inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr,
+                                         Atomic64 new_value) {
+  Atomic64 temp, old;
+  Atomic64 check;
+  __asm__ __volatile__(
+                       "1:\n"
+                       "lr.d %1, (%4)\n"  // old = *ptr
+                       "move %0, %3\n"  // temp = new_value
+                       "sc.d %2, %0, (%4)\n"  // *ptr = temp (with atomic check)
+                       "bnez %2, 1b\n"  // start again on atomic error
+                       "nop\n"  // delay slot nop
+                       : "=&r" (temp), "=&r" (old), "=&r"(check)
+                       : "r" (new_value), "r" (ptr)
+                       : "memory");
+
+  return old;
+}
+
+// Atomically increment *ptr by "increment".  Returns the new value of
+// *ptr with the increment applied.  This routine implies no memory barriers.
+inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
+                                          Atomic32 increment) {
+  Atomic32 temp, temp2;
+  Atomic32 check;
+  __asm__ __volatile__(
+                       "1:\n"
+                       "lr.w %0, (%4)\n"  // temp = *ptr
+                       "addu %1, %0, %3\n"  // temp2 = temp + increment
+                       "sc.w %2, %1, (%4)\n"  // *ptr = temp2 (with atomic check)
+                       "bnez %2, 1b\n"  // start again on atomic error
+                       "addu %1, %0, %3\n"  // temp2 = temp + increment
+                       : "=&r" (temp), "=&r" (temp2), "=&r" (check)
+                       : "r" (increment), "r" (ptr)
+                       : "memory");
+  // temp2 now holds the final value.
+  return temp2;
+}
+
+inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr,
+                                          Atomic64 increment) {
+  Atomic64 temp, temp2;
+  Atomic64 check;
+  __asm__ __volatile__(
+                       "1:\n"
+                       "lr.d %0, (%4)\n"  // temp = *ptr
+                       "addu %1, %0, %3\n"  // temp2 = temp + increment
+                       "sc.d %2, %1, (%4)\n"  // *ptr = temp2 (with atomic check)
+                       "bnez %2, 1b\n"  // start again on atomic error
+                       "addu %1, %0, %3\n"  // temp2 = temp + increment
+                       : "=&r" (temp), "=&r" (temp2), "=&r" (check)
+                       : "r" (increment), "r" (ptr)
+                       : "memory");
+  // temp2 now holds the final value.
+  return temp2;
+}
+
+inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
+                                        Atomic32 increment) {
+  ATOMICOPS_COMPILER_BARRIER();
+  Atomic32 res = NoBarrier_AtomicIncrement(ptr, increment);
+  ATOMICOPS_COMPILER_BARRIER();
+  return res;
+}
+
+inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
+                                        Atomic64 increment) {
+  ATOMICOPS_COMPILER_BARRIER();
+  Atomic64 res = NoBarrier_AtomicIncrement(ptr, increment);
+  ATOMICOPS_COMPILER_BARRIER();
+  return res;
+}
+
+// "Acquire" operations
+// ensure that no later memory access can be reordered ahead of the operation.
+// "Release" operations ensure that no previous memory access can be reordered
+// after the operation.  "Barrier" operations have both "Acquire" and "Release"
+// semantics.   A MemoryBarrier() has "Barrier" semantics, but does no memory
+// access.
+inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
+                                       Atomic32 old_value,
+                                       Atomic32 new_value) {
+  ATOMICOPS_COMPILER_BARRIER();
+  Atomic32 res = NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+  ATOMICOPS_COMPILER_BARRIER();
+  return res;
+}
+
+inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  ATOMICOPS_COMPILER_BARRIER();
+  Atomic64 res = NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+  ATOMICOPS_COMPILER_BARRIER();
+  return res;
+}
+
+inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
+                                       Atomic32 old_value,
+                                       Atomic32 new_value) {
+  ATOMICOPS_COMPILER_BARRIER();
+  Atomic32 res = NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+  ATOMICOPS_COMPILER_BARRIER();
+  return res;
+}
+
+inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  ATOMICOPS_COMPILER_BARRIER();
+  Atomic64 res = NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+  ATOMICOPS_COMPILER_BARRIER();
+  return res;
+}
+
+inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
+  *ptr = value;
+}
+
+inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
+  *ptr = value;
+}
+
+inline void MemoryBarrier() {
+  __asm__ __volatile__("fence rw, rw" : : : "memory");
+}
+
+inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) {
+  *ptr = value;
+  MemoryBarrier();
+}
+
+inline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) {
+  *ptr = value;
+  MemoryBarrier();
+}
+
+inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
+  MemoryBarrier();
+  *ptr = value;
+}
+
+inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
+  MemoryBarrier();
+  *ptr = value;
+}
+
+inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
+  return *ptr;
+}
+
+inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
+  return *ptr;
+}
+
+inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
+  Atomic32 value = *ptr;
+  MemoryBarrier();
+  return value;
+}
+
+inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
+  Atomic64 value = *ptr;
+  MemoryBarrier();
+  return value;
+}
+
+inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
+  MemoryBarrier();
+  return *ptr;
+}
+
+
+inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
+  MemoryBarrier();
+  return *ptr;
+}
+
+}  // namespace internal
+}  // namespace protobuf
+}  // namespace google
+
+#undef ATOMICOPS_COMPILER_BARRIER
+
+#endif  // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_RISCV_GCC_H_
\ No newline at end of file
diff -ur --new-file protobuf-2.5.0/src/google/protobuf/stubs/platform_macros.h protobuf-2.5.0/src/google/protobuf/stubs/platform_macros.h
--- protobuf-2.5.0/src/google/protobuf/stubs/platform_macros.h	2023-07-27 21:16:40.005186825 +0800
+++ protobuf-2.5.0/src/google/protobuf/stubs/platform_macros.h	2023-07-27 21:23:04.021886541 +0800
@@ -63,6 +63,9 @@
 #elif defined(__ppc__) || defined(__PPC__)
 #define GOOGLE_PROTOBUF_ARCH_PPC 1
 #define GOOGLE_PROTOBUF_ARCH_32_BIT 1
+#elif defined(__riscv)
+#define GOOGLE_PROTOBUF_ARCH_RISCV64 1
+#define GOOGLE_PROTOBUF_ARCH_64_BIT 1
 #elif defined(__s390x__)
 #define GOOGLE_PROTOBUF_ARCH_64_BIT 1
 #define GOOGLE_PROTOBUF_ARCH_S390X 1
diff -ur --new-file protobuf-2.5.0/src/Makefile.am protobuf-2.5.0/src/Makefile.am
--- protobuf-2.5.0/src/Makefile.am	2023-07-27 21:17:39.041294096 +0800
+++ protobuf-2.5.0/src/Makefile.am	2023-07-27 21:25:00.466098807 +0800
@@ -48,6 +48,7 @@
   google/protobuf/stubs/atomicops_internals_pnacl.h             \
   google/protobuf/stubs/atomicops_internals_x86_gcc.h           \
   google/protobuf/stubs/atomicops_internals_x86_msvc.h          \
+  google/protobuf/stubs/atomicops_internals_riscv64_gcc.h       \
   google/protobuf/stubs/common.h                                \
   google/protobuf/stubs/platform_macros.h                       \
   google/protobuf/stubs/once.h                                  \
diff -ur --new-file protobuf-2.5.0/src/Makefile.in protobuf-2.5.0/src/Makefile.in
--- protobuf-2.5.0/src/Makefile.in	2023-07-27 21:17:39.041294096 +0800
+++ protobuf-2.5.0/src/Makefile.in	2023-07-27 21:25:59.362209523 +0800
@@ -313,6 +313,7 @@
 	google/protobuf/stubs/atomicops_internals_macosx.h \
 	google/protobuf/stubs/atomicops_internals_mips_gcc.h \
 	google/protobuf/stubs/atomicops_internals_pnacl.h \
+	google/protobuf/stubs/atomicops_internals_riscv64_gcc.h \
 	google/protobuf/stubs/atomicops_internals_x86_gcc.h \
 	google/protobuf/stubs/atomicops_internals_x86_msvc.h \
 	google/protobuf/stubs/common.h \
@@ -525,6 +526,7 @@
   google/protobuf/stubs/atomicops_internals_pnacl.h             \
   google/protobuf/stubs/atomicops_internals_x86_gcc.h           \
   google/protobuf/stubs/atomicops_internals_x86_msvc.h          \
+  google/protobuf/stubs/atomicops_internals_riscv64_gcc.h       \
   google/protobuf/stubs/common.h                                \
   google/protobuf/stubs/platform_macros.h                       \
   google/protobuf/stubs/once.h                                  \
