记录编译的文档
编译Godot
openKylin RISC-V编译运行Godot 4.3 openKylin RISC-V编译运行Godot 4.3 为了扩展openkylin RISC-V游戏生态，我一直在探索Godot这一开源游戏引擎在RISC-V设备上原生编译。以下编译指南，在文章底部提供我编译好的Godot编辑器。
还有，特别感谢感谢Github开发者MBCX的RISC-V交叉编译方法提供帮助和参考！
基础准备
编译Godot至少需要8G内存（4G以及以下容易导致爆内存编译失败），如果不足请开始swap，或者降低JOB数，文档中演示的设备是8G内存，所以没有开启swap。
安装openKylin 2.0 RISC-V镜像，这里演示使用的是SpacemiT K1（Muse Book），请下载安装对应板卡的镜像。
在SpacemiT_K1上安装openKylin | openKylin文档平台
克隆源代码
克隆Godot 4.3源代码
sudo apt install git
git clone https://github.com/godotengine/godot.git -b 4.3-stable --depth=1
安装编译依赖
安装Godot编译依赖
sudo apt update
sudo apt install -y \
build-essential \
pkg-config \
libx11-dev \
libxcursor-dev \
libxinerama-dev \
libgl1-mesa-dev \
libglu1-mesa-dev \
libasound2-dev \
libpulse-dev \
libudev-dev \
libxi-dev \
libxrandr-dev \
libwayland-dev
其中，openKylin 2.0的build-essential中gcc和g++版本默认是12，需要使用update-alternatives修改默认版本，切换到gcc-13和g++-13
# 安装gcc-13 g++-13
sudo apt install gcc-13 g++-13
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 100
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-13 100
# 输入gcc-13对应的数字序号
sudo update-alternatives --config gcc
# g++也是相同的步骤。
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-12 100
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-13 100
# 输入g++-13对应的数字序号
sudo update-alternatives --config g++
Godot项目使用SCons构建，SCons是一个开放源代码、以Python语言编写的自动化构建工具，在openKylin使用pip包安装程序安装SCons。
sudo apt install python3-pip
sudo pip install scons -i https://pypi.tuna.tsinghua.edu.cn/simple --break-system-packages
检查SCons版本
openkylin@openkylin:~/godot$ scons -v
SCons by Steven Knight et al.:
SCons: v4.8.0.7c688f694c644b61342670ce92977bf4a396c0d4, Sun, 07 Jul 2024 16:52:07 -0700, by bdbaddog on M1Dog2021
SCons path: ['/usr/local/lib/python3.12/dist-packages/SCons']
Copyright (c) 2001 - 2024 The SCons Foundation
安装mold和Clang-17
sudo apt update
sudo apt install mold clang-17
检查Clang版本，并确保编译器后端为GCC13，应该有如下输出：
Selected GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/13
openkylin@openkylin:~/godot$ clang -v
Openkylin clang version 17.0.6 (9ok4)
Target: riscv64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/12
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/13
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/8
Selected GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/13
wlcom支持需要安装 wayland-protocols，否则会警告：WARNING: wayland-scanner not found. Disabling Wayland support.
sudo apt update
sudo apt install wayland-protocols
开始构建
cd 进入源码目录构建
cd godot
指定目标架构为rv64，启用Clang作为LLVM编译器前端，指定链接器为mold（GNU ld无法正确链接）并同时禁用链接时优化。
arch="rv64" use_llvm="yes" linker="mold" lto="none"
启用fb文本服务器后端（Godot有两种文本后端fb和adv）
module_text_server_fb_enabled="yes"
安装编译依赖
安装Godot编译依赖
sudo apt update
sudo apt install -y \
build-essential \
pkg-config \
libx11-dev \
libxcursor-dev \
libxinerama-dev \
libgl1-mesa-dev \
libglu1-mesa-dev \
libasound2-dev \
libpulse-dev \
libudev-dev \
libxi-dev \
libxrandr-dev \
libwayland-dev
其中，openKylin 2.0的build-essential中gcc和g++版本默认是12，需要使用update-alternatives修改默认版本，切换到gcc-13和g++-13
# 安装gcc-13 g++-13
sudo apt install gcc-13 g++-13
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 100
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-13 100
# 输入gcc-13对应的数字序号
sudo update-alternatives --config gcc
# g++也是相同的步骤。
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-12 100
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-13 100
# 输入g++-13对应的数字序号
sudo update-alternatives --config g++
Godot项目使用SCons构建，SCons是一个开放源代码、以Python语言编写的自动化构建工具，在openKylin使用pip包安装程序安装SCons。
sudo apt install python3-pip
sudo pip install scons -i https://pypi.tuna.tsinghua.edu.cn/simple --break-system-packages
检查SCons版本
openkylin@openkylin:~/godot$ scons -v
SCons by Steven Knight et al.:
SCons: v4.8.0.7c688f694c644b61342670ce92977bf4a396c0d4, Sun, 07 Jul 2024 16:52:07 -0700, by bdbaddog on M1Dog2021
SCons path: ['/usr/local/lib/python3.12/dist-packages/SCons']
Copyright (c) 2001 - 2024 The SCons Foundation
安装mold和Clang-17
sudo apt install mold clang-17
检查Clang版本，并确保编译器后端为GCC13，应该有如下输出：
Selected GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/13
openkylin@openkylin:~/godot$ clang -v
Openkylin clang version 17.0.6 (9ok4)
Target: riscv64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/12
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/13
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/8
Selected GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/13
开始构建
cd进入源码目录构建
cd godot
指定目标架构为rv64，启用Clang作为LLVM编译器前端，指定链接器为mold（GNU ld无法正确链接）并同时禁用链接时优化。
arch="rv64" use_llvm="yes" linker="mold" lto="none"
启用fb文本服务器后端（Godot有两种文本后端fb和adv）
module_text_server_fb_enabled="yes"
同时需要禁用一些在RISC-V设备可能没法正常工作的Godot模块
同时可以禁用一些在RISC-V设备可能没法正常工作的Godot模块
# 禁用Theora视频编码支持
module_theora_enabled="no"
# 禁用去噪模块
module_denoise_enabled="no"
# 禁用光线投射模块
module_raycast_enabled="no"
# 禁用Xatlas纹理展开模块
module_xatlas_unwrap_enabled="no"
使用以下命令构建Godot编辑器
scons -j8 arch="rv64" use_llvm="yes" linker="mold" lto="none" \
target="editor" platform="linux" \
precision="single" module_text_server_fb_enabled="yes" \
module_theora_enabled="no" \
module_denoise_enabled="no" \
module_raycast_enabled="no" \
module_xatlas_unwrap_enabled="no"
使用以下命令构建Debug导出模板
scons -j8 arch="rv64" use_llvm="yes" linker="mold" lto="none" \
target="template_debug" platform="linux" \
precision="single" module_text_server_fb_enabled="yes" \
module_theora_enabled="no" \
module_denoise_enabled="no" \
module_raycast_enabled="no" \
module_xatlas_unwrap_enabled="no"
使用以下命令构建Release导出模板
scons -j8 arch="rv64" use_llvm="yes" linker="mold" lto="none" \
target="template_release" platform="linux" \
precision="single" module_text_server_fb_enabled="yes" \
module_theora_enabled="no" \
module_denoise_enabled="no" \
module_raycast_enabled="no" \
module_xatlas_unwrap_enabled="no"
清理构建请使用 scons --clean
运行Godot
cd进入bin目录
cd bin
运行Godot编辑器，openKylin 2.0镜像默认使用wlcom（基于Wayland协议），IMG的GPU可以使用GLES，因此需要加上启动参数--display-driver wayland opengl_es3，如果设备可以外接AMD GPU可以尝试用GL（比如SG2042）。
chmod +x godot.linuxbsd.editor.rv64.llvm
./godot.linuxbsd.editor.rv64.llvm --display-driver wayland opengl_es3
杂项
最早在openKylin构建Godot RISC-V的issue：https://github.com/godotengine/godot/issues/91381
向Godot Docs提交的文档说明：
Godot官方添加对RISC-V构建支持的issue：
https://github.com/godotengine/godot-proposals/issues/3374
https://github.com/godotengine/godot/pull/53508 https://github.com/godotengine/godot/pull/53509
为什么要使用gcc 13以及以上版本
https://github.com/godotengine/godot/issues/88634
If you are using GCC12 on VF2, the following error message is displayed:
In file included from ./core/os/memory.h:35,
from ./core/templates/local_vector.h:35,
from ./core/object/message_queue.h:36,
from ./core/object/object.h:35,
from ./core/variant/binder_common.h:35,
from ./core/object/method_bind.h:34,
from ./core/object/class_db.h:34,
from ./core/config/project_settings.h:34,
from platform/linuxbsd/crash_handler_linuxbsd.cpp:33:
./core/templates/safe_refcount.h:157:41: error: static assertion failed
157 | static_assert(std::atomic_bool::is_always_lock_free);
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
In file included from ./core/os/memory.h:35,
from ./core/templates/local_vector.h:35,
from ./core/object/message_queue.h:36,
from ./core/object/object.h:35,
from ./core/variant/binder_common.h:35,
from ./core/object/method_bind.h:34,
from ./core/object/class_db.h:34,
from ./core/object/ref_counted.h:34,
from ./core/io/resource_uid.h:34,
from ./core/io/resource.h:34,
from ./core/input/input_event.h:35,
from ./core/input/input.h:34,
from platform/linuxbsd/joypad_linux.h:36,
from platform/linuxbsd/os_linuxbsd.h:35,
from platform/linuxbsd/godot_linuxbsd.cpp:31:
./core/templates/safe_refcount.h:157:41: error: static assertion failed
157 | static_assert(std::atomic_bool::is_always_lock_free);
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
In file included from ./core/os/memory.h:35,
from ./core/templates/local_vector.h:35,
from ./core/object/message_queue.h:36,
from ./core/object/object.h:35,
from ./core/variant/binder_common.h:35,
from ./core/object/method_bind.h:34,
from ./core/object/class_db.h:34,
from ./core/object/ref_counted.h:34,
from ./core/io/resource_uid.h:34,
from ./core/io/resource.h:34,
from ./core/input/input_event.h:35,
from ./core/input/input.h:34,
from platform/linuxbsd/joypad_linux.h:36,
from platform/linuxbsd/joypad_linux.cpp:33:
./core/templates/safe_refcount.h:157:41: error: static assertion failed
157 | static_assert(std::atomic_bool::is_always_lock_free);
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
In file included from ./core/os/memory.h:35,
from ./core/templates/local_vector.h:35,
from ./core/object/message_queue.h:36,
from ./core/object/object.h:35,
from ./core/variant/binder_common.h:35,
from ./core/object/method_bind.h:34,
from ./core/object/class_db.h:34,
from ./core/object/ref_counted.h:34,
from ./core/io/resource_uid.h:34,
from ./core/io/resource.h:34,
from ./core/input/input_event.h:35,
from ./core/input/input.h:34,
from platform/linuxbsd/joypad_linux.h:36,
from platform/linuxbsd/os_linuxbsd.h:35,
from platform/linuxbsd/os_linuxbsd.cpp:31:
./core/templates/safe_refcount.h:157:41: error: static assertion failed
157 | static_assert(std::atomic_bool::is_always_lock_free);
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
scons: *** [platform/linuxbsd/crash_handler_linuxbsd.linuxbsd.editor.rv64.o] Err or 1
scons: *** [platform/linuxbsd/joypad_linux.linuxbsd.editor.rv64.o] Error 1
scons: *** [platform/linuxbsd/godot_linuxbsd.linuxbsd.editor.rv64.o] Error 1
scons: *** [platform/linuxbsd/os_linuxbsd.linuxbsd.editor.rv64.o] Error 1
scons: building terminated because of errors.
[Time elapsed: 00:00:23.511]
This is probably caused by Godot's compilation ignoring atomic under riscv64, hope this build issue can be fixed, thanks
openkylin@openkylin:~/godot$ scons use_llvm=yes -j3
scons: Reading SConscript files ...
Automatically detected platform: linuxbsd
Building for platform "linuxbsd", architecture "rv64", target "editor".
Checking for C header file mntent.h... yes
scons: done reading SConscript files.
scons: Building targets ...
[ 96%] Linking Program bin/godot.linuxbsd.editor.rv64.llvm ...
[100%] progress_finish(["progress_finish"], [])
[100%] drivers/libdrivers.linuxbsd.editor.rv64.llvm.a(rendering_device_vulkan.linuxbsd.editor.rv64.llvm.o): in function `.LBB173_7':
rendering_device_vulkan.cpp:(.text+0x3d39e): relocation truncated to fit: R_RISCV_BRANCH against `.LBB177_194'
servers/libservers.linuxbsd.editor.rv64.llvm.a(render_forward_mobile.linuxbsd.editor.rv64.llvm.o): in function `.LBB6_20':
render_forward_mobile.cpp:(.text+0xa16): relocation truncated to fit: R_RISCV_BRANCH against `.LBB6_339'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
scons: *** [bin/godot.linuxbsd.editor.rv64.llvm] Error 1
scons: building terminated because of errors.
[Time elapsed: 00:11:06.292]
openkylin@openkylin:~/godot$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/riscv64-linux-gnu/13/lto-wrapper
Target: riscv64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Openkylin 13.2.0-4ok3.3' --with-bugurl=file:///usr/share/doc/gcc-13/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-13 --program-prefix=riscv64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/libexec --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --disable-libquadmath-support --enable-plugin --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --disable-multilib --with-arch=rv64gc --with-abi=lp64d --enable-checking=release --build=riscv64-linux-gnu --host=riscv64-linux-gnu --target=riscv64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=8
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.2.0 (Openkylin 13.2.0-4ok3.3)
openkylin@openkylin:~/godot$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/riscv64-linux-gnu/13/lto-wrapper
Target: riscv64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Openkylin 13.2.0-4ok3.3' --with-bugurl=file:///usr/share/doc/gcc-13/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-13 --program-prefix=riscv64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/libexec --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --disable-libquadmath-support --enable-plugin --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --disable-multilib --with-arch=rv64gc --with-abi=lp64d --enable-checking=release --build=riscv64-linux-gnu --host=riscv64-linux-gnu --target=riscv64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=8
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.2.0 (Openkylin 13.2.0-4ok3.3)
openkylin@openkylin:~/godot$ clang -v
Openkylin clang version 15.0.7
Target: riscv64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/12
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/13
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/8
Found candidate GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/9
Selected GCC installation: /usr/bin/../lib/gcc/riscv64-linux-gnu/13