backend/rv64: Add biscuit as the assembler

CMakeLists.txt

@@ -130,6 +130,7 @@ message(STATUS "Target architecture: ${ARCHITECTURE}")
 # Forced use of individual bundled libraries for non-REQUIRED library is possible with e.g. cmake -DCMAKE_DISABLE_FIND_PACKAGE_fmt=ON ...
 
 if (DYNARMIC_USE_BUNDLED_EXTERNALS)
+    set(CMAKE_DISABLE_FIND_PACKAGE_biscuit ON)
     set(CMAKE_DISABLE_FIND_PACKAGE_Catch2 ON)
     set(CMAKE_DISABLE_FIND_PACKAGE_fmt ON)
     set(CMAKE_DISABLE_FIND_PACKAGE_mcl ON)
@@ -148,6 +149,10 @@ if ("arm64" IN_LIST ARCHITECTURE OR DYNARMIC_TESTS)
     find_package(oaknut 2.0.1 CONFIG)
 endif()
 
+if ("riscv" IN_LIST ARCHITECTURE)
+    find_package(biscuit 0.9.1 QUIET)
+endif()
+
 if ("x86_64" IN_LIST ARCHITECTURE)
     find_package(xbyak 7 CONFIG)
     find_package(Zydis 4 CONFIG)

CMakeModules/dynarmicConfig.cmake.in

@@ -14,6 +14,10 @@ if (NOT @BUILD_SHARED_LIBS@)
         find_dependency(oaknut 2.0.1)
     endif()
 
+    if ("riscv" IN_LIST ARCHITECTURE)
+        find_dependency(biscuit 0.9.1)
+    endif()
+
     if ("x86_64" IN_LIST ARCHITECTURE)
         find_dependency(xbyak 7)
         find_dependency(Zydis 4)

README.md

@@ -216,6 +216,23 @@ dynarmic is under a 0BSD license. See LICENSE.txt for more details.
 
 dynarmic uses several other libraries, whose licenses are included below:
 
+### biscuit
+
+```
+Copyright 2021 Lioncash/Lioncache
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+IN THE SOFTWARE.
+```
+
 ### catch
 
 ```

externals/CMakeLists.txt

@@ -15,6 +15,14 @@ set(BUILD_TESTING OFF)
 # simply add the directory to that file as a subdirectory
 # to have CMake automatically recognize them.
 
+# biscuit
+
+if (NOT TARGET biscuit::biscuit)
+    if ("riscv" IN_LIST ARCHITECTURE)
+        add_subdirectory(biscuit)
+    endif()
+endif()
+
 # catch
 
 if (NOT TARGET Catch2::Catch2WithMain)

externals/README.md

@@ -3,6 +3,7 @@ This repository uses subtrees to manage some of its externals.
 ## Initial setup
 
 ```
+git remote add externals-biscuit https://github.com/lioncash/biscuit.git --no-tags
 git remote add externals-catch https://github.com/catchorg/Catch2.git --no-tags
 git remote add externals-fmt https://github.com/fmtlib/fmt.git --no-tags
 git remote add externals-mcl https://github.com/merryhime/mcl.git --no-tags
@@ -18,6 +19,7 @@ git remote add externals-zydis https://github.com/zyantific/zydis.git --no-tags
 Change `<ref>` to refer to the appropriate git reference.
 
 ```
+git fetch externals-biscuit
 git fetch externals-catch
 git fetch externals-fmt
 git fetch externals-mcl
@@ -26,6 +28,7 @@ git fetch externals-robin-map
 git fetch externals-xbyak
 git fetch externals-zycore
 git fetch externals-zydis
+git subtree pull --squash --prefix=externals/biscuit externals-biscuit <ref>
 git subtree pull --squash --prefix=externals/catch externals-catch <ref>
 git subtree pull --squash --prefix=externals/fmt externals-fmt <ref>
 git subtree pull --squash --prefix=externals/mcl externals-mcl <ref>

src/dynarmic/CMakeLists.txt

@@ -400,6 +400,8 @@ if ("arm64" IN_LIST ARCHITECTURE)
 endif()
 
 if ("riscv" IN_LIST ARCHITECTURE)
+    target_link_libraries(dynarmic PRIVATE biscuit::biscuit)
+
     if ("A32" IN_LIST DYNARMIC_FRONTENDS)
         target_sources(dynarmic PRIVATE
             backend/riscv64/a32_address_space.cpp
@@ -408,7 +410,6 @@ if ("riscv" IN_LIST ARCHITECTURE)
             backend/riscv64/a32_interface.cpp
             backend/riscv64/a32_jitstate.cpp
             backend/riscv64/a32_jitstate.h
-            backend/riscv64/dummy_code_block.h
         )
     endif()
 

src/dynarmic/backend/exception_handler.h

@@ -22,7 +22,7 @@ class CodeBlock;
 }  // namespace oaknut
 #elif defined(MCL_ARCHITECTURE_RISCV)
 namespace Dynarmic::Backend::RV64 {
-class DummyCodeBlock;
+class CodeBlock;
 }  // namespace Dynarmic::Backend::RV64
 #else
 #    error "Invalid architecture"
@@ -56,7 +56,7 @@ public:
 #elif defined(MCL_ARCHITECTURE_ARM64)
     void Register(oaknut::CodeBlock& mem, std::size_t mem_size);
 #elif defined(MCL_ARCHITECTURE_RISCV)
-    void Register(RV64::DummyCodeBlock& mem, std::size_t mem_size);
+    void Register(RV64::CodeBlock& mem, std::size_t mem_size);
 #else
 #    error "Invalid architecture"
 #endif

src/dynarmic/backend/exception_handler_generic.cpp

@@ -22,7 +22,7 @@ void ExceptionHandler::Register(oaknut::CodeBlock&, std::size_t) {
     // Do nothing
 }
 #elif defined(MCL_ARCHITECTURE_RISCV)
-void ExceptionHandler::Register(RV64::DummyCodeBlock&, std::size_t) {
+void ExceptionHandler::Register(RV64::CodeBlock&, std::size_t) {
     // Do nothing
 }
 #else

src/dynarmic/backend/exception_handler_posix.cpp

@@ -33,7 +33,7 @@
 
 #    include "dynarmic/backend/arm64/abi.h"
 #elif defined(MCL_ARCHITECTURE_RISCV)
-#    include "dynarmic/backend/riscv64/dummy_code_block.h"
+#    include "dynarmic/backend/riscv64/code_block.h"
 #else
 #    error "Invalid architecture"
 #endif
@@ -313,7 +313,7 @@ void ExceptionHandler::Register(oaknut::CodeBlock& mem, std::size_t size) {
     impl = std::make_unique<Impl>(code_begin, code_end);
 }
 #elif defined(MCL_ARCHITECTURE_RISCV)
-void ExceptionHandler::Register(RV64::DummyCodeBlock& mem, std::size_t size) {
+void ExceptionHandler::Register(RV64::CodeBlock& mem, std::size_t size) {
     const u64 code_begin = mcl::bit_cast<u64>(mem.ptr());
     const u64 code_end = code_begin + size;
     impl = std::make_unique<Impl>(code_begin, code_end);

src/dynarmic/backend/riscv64/code_block.h

@@ -0,0 +1,42 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2024 MerryMage
+ * SPDX-License-Identifier: 0BSD
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <new>
+
+#include <biscuit/assembler.hpp>
+#include <sys/mman.h>
+
+namespace Dynarmic::Backend::RV64 {
+
+class CodeBlock {
+public:
+    explicit CodeBlock(std::size_t size)
+            : memsize(size) {
+        mem = (std::uint32_t*)mmap(nullptr, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANON | MAP_PRIVATE, -1, 0);
+
+        if (mem == nullptr)
+            throw std::bad_alloc{};
+    }
+
+    ~CodeBlock() {
+        if (mem == nullptr)
+            return;
+
+        munmap(mem, memsize);
+    }
+
+    std::uint32_t* ptr() const {
+        return mem;
+    }
+
+protected:
+    std::uint32_t* mem;
+    std::size_t memsize = 0;
+    biscuit::Assembler as;
+};
+}  // namespace Dynarmic::Backend::RV64

src/dynarmic/backend/riscv64/dummy_code_block.h

@@ -1,16 +0,0 @@
-/* This file is part of the dynarmic project.
- * Copyright (c) 2024 MerryMage
- * SPDX-License-Identifier: 0BSD
- */
-
-#pragma once
-
-namespace Dynarmic::Backend::RV64 {
-
-class DummyCodeBlock {
-public:
-    DummyCodeBlock() {}
-
-    void* ptr() { return nullptr; }
-};
-}  // namespace Dynarmic::Backend::RV64