MegEngine/scripts/cmake-build/BUILD_README.md

• build support status
• • host build
  • cross build
• build env prepare
• • package install
  • • windows host build
    • linux host build
    • macos host build
    • cross build for arm-android
    • cross build for arm-linux
    • cross build for ios
  • third-party code prepare
  • • with bash env(linux/macos/unix-like tools on windows, eg: msys etc)
    • windows shell env(eg: cmd, powershell etc)
• how to build
• • with bash env(linux/macos/unix-like tools on windows, eg: msys etc)
  • windows shell env(eg: cmd, powershell etc)
  • Visual Studio GUI(only for windows host)
• other arm-linux-like board support

build support status

host build

• windows build (ok)
• linux build (ok)
• macos build (ok)

cross build

• windows cross build arm-android (ok)
• windows cross build arm-linux (ok)
• linux cross build arm-android (ok)
• linux cross build arm-linux (ok)
• macos cross build arm-android (ok)
• macos cross build arm-linux (ok but experimental)
• macos cross build ios (ok)

build env prepare

package install

windows host build

```
1: installl Visual Studio (need support LLVM/clang-cl), eg 2019
clang-cl 9 linker have crash issue, pls install 7/8/10
2: install extension of VS: python/cmake/LLVM
3: CUDA env(if enable CUDA), version detail: project_root_dir/README.md
```

linux host build

```
1: cmake, which version > 3.14.4
2: gcc/g++, which version > 6
3: install build-essential git git-lfs gfortran libgfortran-6-dev autoconf gnupg flex bison gperf curl 
4: zlib1g-dev gcc-multilib g++-multilib lib32ncurses5-dev libxml2-utils xsltproc unzip libtool:
5: librdmacm-dev rdmacm-utils python3-dev swig python3-numpy texinfo
6: CUDA env(if enable CUDA), version detail: project_root_dir/README.md
```

macos host build

```
1: cmake, which version > 3.14.4
2: install brew: /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
3: brew install python python3 swig coreutils
4: install at least xcode command line tool: https://developer.apple.com/xcode/
5: about cuda: we do not support CUDA on macos
```

cross build for arm-android

now we support windows/linux/macos cross build to arm-android
```
1: install unix-like tools, eg MSYS if you are using windows(recommend)
we also support CMD.exe or powershell on windows
1: download NDK from https://developer.android.google.cn/ndk/downloads/
for diff OS platform package, suggested NDK20 or NDK21
2: export NDK_ROOT=NDK_DIR at bash-like env
3: config NDK_ROOT to PATH env at windows control board if use CMD/powershell
```

cross build for arm-linux

now we support arm-linux on linux and windows fully, also experimental on MACOS
```
1: download toolchains on https://releases.linaro.org/components/toolchain/gcc-linaro/
or https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-a/downloads
if use windows or linux
2: download https://github.com/thinkski/osx-arm-linux-toolchains if use MACOS
```

cross build for ios

now we only support cross build to ios on MACOS
```
1: install full xcode: https://developer.apple.com/xcode/
```

third-party code prepare

with bash env(linux/macos/unix-like tools on windows, eg: msys etc)

```
./third_party/prepare.sh
./third_party/install-mkl.sh
```

windows shell env(eg: cmd, powershell etc)

infact if you can use git command on windows, which means you always install
bash.exe at the same dir of git.exe, find it, then you can prepare third-party
code by command:
```
bash.exe ./third_party/prepare.sh
bash.exe ./third_party/install-mkl.sh
```

how to build

with bash env(linux/macos/unix-like tools on windows, eg: msys etc)

```
1: host build just use scripts:scripts/cmake-build/host_build.sh
2: cross build to arm-android: scripts/cmake-build/cross_build_android_arm_inference.sh
3: cross build to arm-linux:   scripts/cmake-build/cross_build_linux_arm_inference.sh
4: cross build to ios:         scripts/cmake-build/cross_build_ios_arm_inference.sh
```

windows shell env(eg: cmd, powershell etc)

```
1: we do not provide BAT for cmd/powershlel scripts, BUT u can refs for scripts/cmake-build/*.sh
```

Visual Studio GUI(only for windows host)

```
1: import megengine src to Visual Studio as a project
2: right click CMakeLists.txt, choose config 'cmake config'
   choose clang_cl_x86 or clang_cl_x64
3: config other CMAKE config, eg, CUDA ON OR OFF
```

other arm-linux-like board support

it`s easy to support other customized arm-linux-like board, example:
1: HISI 3516/3519, infact u can just use toolchains from arm developer or linaro
then call scripts/cmake-build/cross_build_linux_arm_inference.sh to build a ELF
binary, or if you get HISI official toolschain, you just need modify CMAKE_CXX_COMPILER
and CMAKE_C_COMPILER in toolchains/arm-linux-gnueabi* to a real name

2: about Raspberry, just use scripts/cmake-build/cross_build_linux_arm_inference.sh