• 2021년 4월 7일 : 처음씀
• 2021년 7월 5일 : 참조 내용 추가
  
  

• "build_dir/host" , for compiling all the tools that run on the host computer (OpenWRT builds its own version of sed and many other tools from source). This area will be use for compiling programs that run only on your host.
• "build_dir/toolchain..." for compiling the cross-C compiler and C standard library components that will be used to build the packages. This area will be use for compiling programs that run only on your host (the cross C compiler, for example) and also, libraries designed to run on the target that are linked to - e.g. uClibc, libm, pthreads, etc.
• "build_dir/target..." for compiling the actual packages, and the Linux kernel, for the target system

• "staging_dir/host" is a mini Linux root with its own bin/, lib/, etc. that the host tools are installed into; the rest of the build system then prefixes its PATH with directories in this area
• "staging_dir/toolchain..." is a mini Linux root with its own bin/, lib/, etc that contains the cross C compiler used to build the rest of the firmware. You can actually use that to compile simple C programs outside of OpenWRT that can be loaded onto the firmware. The C compiler might be something like: staging_dir/toolchain-mips_34kc_gcc-4.8-linaro_uClibc-0.9.33.2/bin/mips-openwrt-linux-uclibc-gcc. You can see the version of the CPU, the C library and gcc encoded into it; this allows multiple targets to be built in the same area concurrently.
• "staging_dir/target.../root-..." contains “installed” versions of each target package again arranged with bin/, lib/, this will become the actual root directory that with some tweaking will get zipped up into the firmware image, something like root-ar71xx. There are some other files in staging_dir/target… primarily used for generating the packages and development packages, etc.

1. tools – automake, autoconf, sed, cmake
2. toolchain/binutils – as, ld, …
3. toolchain/gcc – gcc, g++, cpp, …
4. target/linux – kernel modules
5. package – core and feed packages
   1. make package/example/download - download the soures of example
   2. make package/example/prepare - extract the sources, apply patches and download if necessary
   3. make package/example/compile - compile example, prepare and download if necessary
   4. make package/example/clean - clean the sourcecode
   5. make package/index - build a repository index to make the output directory usable as local opkg source
6. target/linux – kernel image
7. target/linux/image – firmware image file generation

• make target/compile
• make package/cleanup
• make package/compile
• make package/install
• make package/preconfig
• make target/install
• make package/index

• make 명령행 실행시 V 인자변수 또는 OPENWRT_VERBOSE 환경변수에 다음의 값을 하나이상의 조합하여 사용 가능.
  • s : stdout + stderr (예전에는 V=99 로 사용했던 옵션)
  • c : 명령들 (명령
  • w : 경고 또는 에러만 (예전에는 V=1 로 사용했던 옵션)
• 예)

  $ make V=sc
  ...
  $ make V=sw
  ...
  

• "make -j $(($(nproc) + 1))" 와 같이 통상적으로는 Core 수에 1을 더한 수만큼을 job으로 잡으면 무난.
• 빌드 전 "make download"를 통하여 download 시 발생될 수 있는 실패확률을 미리 다운로드 받아두게 하여 실패 발생률을 낮추는것을 권장
• 하나의 명령을 2개 이상의 패키지에서 중복되어 지원되는 경우가 있는데 이 경우 충돌이 빌드과정에서 일어날 수 있습니다. 중복된 기능/파일을 갖는 패키지는 하나만 선택하도록 설정을 검토하는게 바람직하며 그렇지 않을 경우도 빌드 순서에 따라서 실패 또는 성공이 명확하지 않을 때가 있으므로 설정에 주의가 필요합니다.

src-git packages https://git.openwrt.org/feed/packages.git
src-git luci https://git.openwrt.org/project/luci.git
src-git routing https://git.openwrt.org/feed/routing.git
src-git telephony https://git.openwrt.org/feed/telephony.git
#src-git video https://github.com/openwrt/video.git
#src-git targets https://github.com/openwrt/targets.git
#src-git management https://github.com/openwrt-management/packages.git
#src-git oldpackages http://git.openwrt.org/packages.git
#src-link custom /usr/src/openwrt/custom-feed

#src-git local_feed_name https://example.com/repo_name/something.git;branch_name
#src-git local_feed_name https://example.com/repo_name/something.git^commit_hash

• src-bzr : Data is downloaded from the source path/URL using bzr
• src-cpy : Data is copied from the source path. The path can be specified as either relative to OpenWrt repository root or absolute.
• src-darcs : Data is downloaded from the source path/URL using darcs
• src-git : Data is downloaded from the source path/URL using git as a shallow (depth of 1) clone
• src-git-full : Data is downloaded from the source path/URL using git as a full clone
• src-gitsvn : Bidirectional operation between a Subversion repository and git
• src-hg : Data is downloaded from the source path/URL using hg
• src-link : A symlink to the source path is created. The path must be absolute.
• src-svn : Data is downloaded from the source path/URL using svn

• feeds.conf 가 수정되거나 feeds.conf 가 가르키고 있는 feeds 내용이 변경되는 경우 다음과 같이 'scripts/feeds' 스크립트 명령을 통해서 이를 반영해야 합니다.

  $ ./scripts/feeds update -a
  $ ./scripts/feeds install -a -f
  

• feeds.conf 가 재 반영되면 이에 따른 설정을 다시 할 수 있는데 다음과 같이 실행하여 설정을 검토하고 수정하여 저장해야 합니다.

  $ make menuconfig
  

• package/Makefile : 다운로드와 컴파일에 필요한 사항들을 명시
• package/patches
• package/files

• PKG_NAME - The name of the package, as seen via menuconfig and ipkg. Avoid using underscores in the package name, to avoid build failures–for example, the underscore separates name from version information, and may confuse the build system in hard-to-spot places.
• PKG_VERSION - The upstream version number that we're downloading
• PKG_RELEASE - The version of this package Makefile
• PKG_LICENSE - The license(s) the package is available under, SPDX form.
• PKG_LICENSE_FILES- file containing the license text
• PKG_BUILD_DIR - Where to compile the package
• PKG_SOURCE - The filename of the original sources
• PKG_SOURCE_URL - Where to download the sources from (directory)
• PKG_HASH - A checksum to validate the download. It can be either a MD5 or SHA256 checksum, but SHA256 should be used, see scripts/download.pl
• PKG_CAT - How to decompress the sources (zcat, bzcat, unzip)
• PKG_BUILD_DEPENDS - Packages that need to be built before this package. Use this option if you need to make sure that your package has access to includes and/or libraries of another package at build time. Specify the directory name (i.e. openssl) rather than the binary package name (i.e. libopenssl). This build variable only establishes the build time dependency. Use DEPENDS to establish the runtime dependencies. This variable uses the same syntax as DEPENDS below.
• PKG_CONFIG_DEPENDS - specifies which config options influence the build configuration and should trigger a rerun of Build/Configure on change
• PKG_INSTALL - Setting it to “1” will call the package's original “make install” with prefix set to PKG_INSTALL_DIR
• PKG_INSTALL_DIR - Where “make install” copies the compiled files
• PKG_FIXUP - See below
  • PKG_FIXUP:=autoreconf
  • PKG_FIXUP:=patch-libtool
  • PKG_FIXUP:=gettext-version

• PKG_SOURCE_PROTO - the protocol to use for fetching the sources (git, svn, etc).
  • PKG_SOURCE_PROTO:=bzr
  • PKG_SOURCE_PROTO:=cvs
  • PKG_SOURCE_PROTO:=darcs
  • PKG_SOURCE_PROTO:=git
  • PKG_SOURCE_PROTO:=hg
  • PKG_SOURCE_PROTO:=svn
• PKG_SOURCE_URL - source repository to fetch from. The URL scheme must be consistent with PKG_SOURCE_PROTO (e.g. git://), but most VCS accept http:// or https:// URLs nowadays.
• PKG_SOURCE_VERSION - must be specified, the commit hash or SVN revision to check out.
• PKG_SOURCE_DATE - a date like 2017-12-25, will be used in the name of generated tarballs.
• PKG_MIRROR_HASH - SHA256 checksum of the tarball generated from the source repository checkout (previously named PKG_MIRROR_MD5SUM). See below for details.
• PKG_SOURCE_SUBDIR - where the temporary source checkout should be stored, defaults to $(PKG_NAME)-$(PKG_VERSION)

• Documentation(https://openwrt.org/docs/start)
  • Quick start guide(https://openwrt.org/docs/guide-quick-start/start)

    Requirements
        binutils bzip2 diff find flex gawk gcc-6+ getopt grep install libc-dev libz-dev make4.1+ perl python3.6+ rsync subversion unzip which
    
    Quickstart
        1. Run ./scripts/feeds update -a to obtain all the latest package definitions defined in feeds.conf / feeds.conf.default
        2. Run ./scripts/feeds install -a to install symlinks for all obtained packages into package/feeds/
        3. Run make menuconfig to select your preferred configuration for the toolchain, target system & firmware packages.
        4. Run make to build your firmware. This will download all sources, build the cross-compile toolchain and then cross-compile the GNU/Linux kernel & all chosen applications for your target system.
    
    License
        OpenWrt is licensed under GPL-2.0
    

  • User guide(https://openwrt.org/docs/guide-user/start)
  • Developer guide(https://openwrt.org/docs/guide-developer/start)
    • The build system(https://openwrt.org/docs/guide-developer/build-system/start)
      • Build system setup(https://openwrt.org/docs/guide-developer/build-system/install-buildsystem)
      • Build system usage(https://openwrt.org/docs/guide-developer/build-system/use-buildsystem)
      • OpenWrt Feeds(https://openwrt.org/docs/guide-developer/feeds)
      • Creating packages(https://openwrt.org/docs/guide-developer/packages)
      • Overriding Build Options(https://openwrt.org/docs/guide-developer/packages.flags)
      • procd init script parameters(https://openwrt.org/docs/guide-developer/procd-init-scripts)
        • Create a sample procd init script(https://openwrt.org/docs/guide-developer/procd-init-script-example)
    • Using Dependencies(https://openwrt.org/docs/guide-developer/dependencies)
  • Technical Reference(https://openwrt.org/docs/techref/start)
  • OpenWrt Buildroot – Technical Reference(https://openwrt.org/docs/techref/buildroot)
• OpenWrt Hardware Database(https://openwrt.org/supported_devices)
• Forum(https://forum.openwrt.org/)
• Bug Reports(https://bugs.openwrt.org/)
• Dev Mailing List(https://lists.openwrt.org/mailman/listinfo/openwrt-devel)
• Support Chat(https://webchat.freenode.net/#openwrt), Dev Chat(https://webchat.freenode.net/#openwrt-devel)
• The master OpenWrt/LEDE source code repositories reside on the OpenWrt/LEDE Project git server(https://git.openwrt.org/)
• The OpenWrt/LEDE Project keeps a mirror of the master repository on GitHub(https://github.com/openwrt)
• OpenWrt source archive(https://sources.openwrt.org/)
  • Any OpenWrt development happens in the main openwrt.git repository which is accessible via both HTTP and HTTPS:

    git clone https://git.openwrt.org/openwrt/openwrt.git
    

  • You can find a mirror of the repository on Github:

    git clone https://github.com/openwrt/openwrt.git
    

• GNU Automake manual 번역본: http://korea.gnu.org/manual/release/automake/
• GNU make manual 번역본
  • 1부: http://korea.gnu.org/manual/release/make/make-sjp/
  • 2부: http://korea.gnu.org/manual/release/make/make-cwryu/