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docs:guide-developer:package-policies [2020/03/04 17:40] – [OpenWrt packages] adamkpickeringdocs:guide-developer:package-policies [2021/10/15 08:32] (current) – ↷ Links adapted because of a move operation bobafetthotmail
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 Almost all pieces of software found in a typical OpenWrt firmware image are Almost all pieces of software found in a typical OpenWrt firmware image are
-provided by such a package with notable exception being the Linux kernel itself.+provided by such a package with a notable exception being the Linux kernel itself.
  
 The term //OpenWrt package// may either refer to one of two things: The term //OpenWrt package// may either refer to one of two things:
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   * an OpenWrt //source package// which essentially is a directory consisting of:   * an OpenWrt //source package// which essentially is a directory consisting of:
-    * an //OpenWrt package Makefile// describing the acquisition, building and packaging procedures for a piece of software +    * an //OpenWrt package Makefile// describing the acquisition, building and packaging procedures for a piece of software (required) 
-    * an optional supplemental directory with //OpenWrt package patches// which modify the acquired source code +    * a supplemental directory with //OpenWrt package patches// which modify the acquired source code (optional) 
-    * optionally further, static supplemental files shipped along with the package, such as init script files, default configurations, scripts or other support files+    * other static files that go with the package, such as init script files, default configurations, scripts or other support files (optional)
  
   * an OpenWrt //binary package//, which is a GNU tar compatible archive containing binary executable software artifacts and the accompanying //package control files// for installation on a running system, similar to the ''.deb'' or ''.rpm'' files used in other package managers   * an OpenWrt //binary package//, which is a GNU tar compatible archive containing binary executable software artifacts and the accompanying //package control files// for installation on a running system, similar to the ''.deb'' or ''.rpm'' files used in other package managers
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 Patch files must be in //unified diff// format and carry the extension ''.patch''. Patch files must be in //unified diff// format and carry the extension ''.patch''.
 The file names must also carry a numerical prefix to denote the order in which the patch The file names must also carry a numerical prefix to denote the order in which the patch
-files must be applied. Patch file names should be short and concise and avoid special +files must be applied. 
-characters such as white spaces, special characters and so on.+Patch file names should be concise and avoid characters other than ASCII alphanumerics and hyphens.
  
 Suitable patch file names could look like: Suitable patch file names could look like:
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   * ''999-add-local-hack-for-openwrt-compatibility.patch''   * ''999-add-local-hack-for-openwrt-compatibility.patch''
  
-It is recommended to use [[docs:guide-developer:build-system:use-patches-with-buildsystem|Quilt]] to manage source package patch collections.+It is recommended to use [[docs:guide-developer:toolchain:use-patches-with-buildsystem|Quilt]] to manage source package patch collections.
  
 === The src directory === === The src directory ===
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 ==== Feature Considerations ==== ==== Feature Considerations ====
  
-Many OpenWrt supported devices still have only a few megabytes of flash and ram available which makes it important to shrink the packages as much as possible. Opt for the lowest common denominator whenever possible.+Many OpenWrt supported devices still have only a few megabytes of flash and RAM available which makes it important to shrink the packages as much as possible. Opt for the lowest common denominator whenever possible.
  
 Some general considerations when packaging a new piece of software are: Some general considerations when packaging a new piece of software are:
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   * Minimize external dependencies - try to avoid optional external dependencies whenever possible. An extreme example is ''ICU'' which weighs around 12MB and is an optional dependency for Unicode multi language support in various packages   * Minimize external dependencies - try to avoid optional external dependencies whenever possible. An extreme example is ''ICU'' which weighs around 12MB and is an optional dependency for Unicode multi language support in various packages
   * Modularize packages - if the software you're packaging supports and uses plugins then put those plugins into separate binary package declarations instead of lumping them all together along with the main program. This way you can externalize dependencies and move them into the plugin packages instead of having them in the main component, which makes the package usable on a wider range of targets because users can omit parts with large dependencies.   * Modularize packages - if the software you're packaging supports and uses plugins then put those plugins into separate binary package declarations instead of lumping them all together along with the main program. This way you can externalize dependencies and move them into the plugin packages instead of having them in the main component, which makes the package usable on a wider range of targets because users can omit parts with large dependencies.
-  * Try to rely on standard facilities - instead of requiring extra programs to implement tasks like user context switching, use the ''procd'' facilities to run a service as a different user+  * Try to rely on standard facilities - instead of requiring extra programs to implement tasks like user context switching, use the ''procd'' facilities to run a service as a different user.
  
 Often it is tempting to add various ''menuconfig'' configuration options to allow the customization of the package features by the users compiling their own variant of OpenWrt but it should be kept in mind that large parts of the userbase will use the package solely by installing binary archives from the OpenWrt repositories. Often it is tempting to add various ''menuconfig'' configuration options to allow the customization of the package features by the users compiling their own variant of OpenWrt but it should be kept in mind that large parts of the userbase will use the package solely by installing binary archives from the OpenWrt repositories.
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 Since contributors likely do not have a formal contract with OpenWrt to develop packages, they cannot disclaim their own copyrights and assign them to the project. Since contributors likely do not have a formal contract with OpenWrt to develop packages, they cannot disclaim their own copyrights and assign them to the project.
  
-When adding new packages please don't simply copy the statement from another package but add either your own in the form:+When adding new packages, please don't simply copy the statement from another package but add either your own in the form:
  
   # Copyright (C) 2016 Joe Random <joe@example.org>   # Copyright (C) 2016 Joe Random <joe@example.org>
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 ==== Versioning ==== ==== Versioning ====
  
-There are a number of Makefile variables influencing the visible version of the resulting packages. When packaging upstream release tarballs, the ''PKG_VERSION'' variable should be set to the version of the upstream software being packaged. If for example the ''openssl'' package compiles the released ''openssl-1.0.2q.tar.gz'' archive, then ''PKG_VERSION'' variable should be set to the value ''1.0.2q''.+There are a number of Makefile variables influencing the visible version of the resulting packages. When packaging upstream release tarballs, the ''PKG_VERSION'' variable should be set to the version of the upstream software being packaged. 
 +For example, if the ''openssl'' package compiles the released ''openssl-1.0.2q.tar.gz'' archive, then ''PKG_VERSION'' variable should be set to the value ''1.0.2q''.
  
-When there are no upstream release tarballs available or when software is packaged straight from a source code repository, the ''PKG_SOURCE_DATE'' and ''PKG_SOURCE_VERSION'' variables should be used instead. The ''PKG_SOURCE_DATE'' value must correspond to the modification date in the format ''YYYY-MM-DD'' of the source repository revision being packaged and ''PKG_SOURCE_VERSION'' must be set to the corresponding revision identifier of the repository, e.g. the commit hash for Git or the revision number for SVN repositories. If for example the ''ubus'' package clones from Git revision https://git.openwrt.org/?p=project/ubus.git;a=commitdiff;h=221ce7e7ff1bd1a0c9995fa9d32f58e865f7207f, then its Makefile should specify ''PKG_SOURCE_DATE:=2018-10-06'' and ''PKG_SOURCE_VERSION:=221ce7e7ff1bd1a0c9995fa9d32f58e865f7207f''.+When there are no upstream release tarballs available or when software is packaged straight from a source code repository, the ''PKG_SOURCE_DATE'' and ''PKG_SOURCE_VERSION'' variables should be used instead. The ''PKG_SOURCE_DATE'' value must correspond to the modification date in the format ''YYYY-MM-DD'' of the source repository revision being packaged and ''PKG_SOURCE_VERSION'' must be set to the corresponding revision identifier of the repository, e.g. the commit hash for Git or the revision number for SVN repositories. 
 +For example, if the ''ubus'' package clones from Git revision https://git.openwrt.org/?p=project/ubus.git;a=commitdiff;h=221ce7e7ff1bd1a0c9995fa9d32f58e865f7207f, then its Makefile should specify ''PKG_SOURCE_DATE:=2018-10-06'' and ''PKG_SOURCE_VERSION:=221ce7e7ff1bd1a0c9995fa9d32f58e865f7207f''.
  
 The build system will combine these variables into a common version identifier and truncate the revision identifier if needed. Given the values in the example, the resulting version identifier will be ''2018-10-06-221ce7e7''. This is done to make repository revision identifiers comparable to each other since SCM systems like Git or Mercurial use SHA hashes to identify revisions which are no monotonically increasing numerical values. The build system will combine these variables into a common version identifier and truncate the revision identifier if needed. Given the values in the example, the resulting version identifier will be ''2018-10-06-221ce7e7''. This is done to make repository revision identifiers comparable to each other since SCM systems like Git or Mercurial use SHA hashes to identify revisions which are no monotonically increasing numerical values.
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 === Mirror Sites === === Mirror Sites ===
  
-The use of mirror sites for tarball download locations is encouraged and helps to reduce the traffic load on upstream project sites. When choosing mirrors for a package, please try to ensure that:+The use of mirror sites for tarball download locations is encouraged and helps to reduce the traffic load on upstream project sites. When choosing mirrors for a package, please try to ensure that the mirror is:
  
-  * The mirror is officially endorsed by the upstream project (e.g. mentioned on their download page) +  * officially endorsed by the upstream project (E.G. mentioned on their download page). 
-  * Is well reachable by people from a wide range of different locations +  * well reachable by people from a wide range of different locations. 
-  * Is using proper SSL certificates when operating HTTPS +  * using proper SSL certificates when using HTTPS. 
-  * Is hosting the most current version of the software in question.+  * hosting the most current version of the software in question.
  
-Multiple mirrors can be specified in a package Makefile by assigning a white-space separated list of URLs to the ''PKG_SOURCE_URL'' variable. It is a good convention to assign the upstream project site itself to the end of the mirror list, to have a canonical fallback location in case a new version has not yet propagated to all mirrors, and to convey the original download location to casual readers.+Multiple mirrors can be specified in a package Makefile by assigning a white-space separated list of URLs to the ''PKG_SOURCE_URL'' variable. 
 +It is a good convention to assign the upstream project site itself to the end of the mirror list. 
 +This provides a canonical fallback location in case a new version has not yet propagated to all mirrors and conveys the original download location to casual readers.
  
 Try to limit the amount of mirror sites to 3 to 5 different locations, including the main download site. Try to limit the amount of mirror sites to 3 to 5 different locations, including the main download site.
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 In some cases it is possible to arrange things before e.g. the In some cases it is possible to arrange things before e.g. the
 ''./configure'' script is invoked in order to touch files, remove things ''./configure'' script is invoked in order to touch files, remove things
-or echo values into stampfiles. In such cases it is permissible to+or echo values into stampfiles. In such cases, it is permissible to
 redefine the recipe in order to achieve the desired result. Use the redefine the recipe in order to achieve the desired result. Use the
 default implementations of the macros to call the original behaviour default implementations of the macros to call the original behaviour
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 Due to the complex nature of the GNU autoconf/automake system there is no single set of solutions to a given problem but rather a general list of guidelines and best practices to adhere to. Due to the complex nature of the GNU autoconf/automake system there is no single set of solutions to a given problem but rather a general list of guidelines and best practices to adhere to.
  
-  * Never patch the generated / shipped ''configure'' script but fix the underlying ''configure.ac'' or ''configure.in'' files and rely on the ''PKG_FIXUP:=autoreconf'' facility to regenerated the config script. This also has the nice side-effect of updating embedded ''libtool'' version and using a cross-compile-safe set of standard macros, replacing unsafe ones in many cases+  * Never patch the generated / shipped ''configure'' script but fix the underlying ''configure.ac'' or ''configure.in'' files and rely on the ''PKG_FIXUP:=autoreconf'' facility to regenerate the config script. This also has the nice side-effect of updating the embedded ''libtool'' version and using a cross-compile-safe set of standard macros, replacing unsafe ones in many cases.
   * Make ''./configure'' invocations as explicit as possible by forcibly disabling or enabling any feature which depends on the presence of an external library, e.g. ''--disable-acl'' to build a given package without ''libacl'' support on both systems having ''libacl'' in their staging directory and systems not providing this library. Failure to do so will result in errors like ''Package example is missing dependencies for the following libraries: libfoo.so.1'' on systems that happen to build ''libfoo'' before building example.   * Make ''./configure'' invocations as explicit as possible by forcibly disabling or enabling any feature which depends on the presence of an external library, e.g. ''--disable-acl'' to build a given package without ''libacl'' support on both systems having ''libacl'' in their staging directory and systems not providing this library. Failure to do so will result in errors like ''Package example is missing dependencies for the following libraries: libfoo.so.1'' on systems that happen to build ''libfoo'' before building example.
   * Pre-seed ''configure'' tests that cannot be reliably determined in a cross-compile setting. Properly written autoconf test macros can be overridden by cache-variables in the form ''ac_cv_somename=value'' - use this facility to skip tests which would otherwise fail or result in host-system specific values. For example the ''libpcap'' package passes ''ac_cv_linux_vers=$(LINUX_VERSION)'' to prevent ''./configure'' from calling the host systems ''uname'' in order to figure out the kernel version. The names of the involved cache variables can be found in the ''config.log'' file within the package build directory or by inspecting the generated shell code of the ''configure'' program. Use the ''CONFIGURE_VARS'' variable to pass the cache variables down to the actual ''./configure'' invocation   * Pre-seed ''configure'' tests that cannot be reliably determined in a cross-compile setting. Properly written autoconf test macros can be overridden by cache-variables in the form ''ac_cv_somename=value'' - use this facility to skip tests which would otherwise fail or result in host-system specific values. For example the ''libpcap'' package passes ''ac_cv_linux_vers=$(LINUX_VERSION)'' to prevent ''./configure'' from calling the host systems ''uname'' in order to figure out the kernel version. The names of the involved cache variables can be found in the ''config.log'' file within the package build directory or by inspecting the generated shell code of the ''configure'' program. Use the ''CONFIGURE_VARS'' variable to pass the cache variables down to the actual ''./configure'' invocation
-  * Never trust shipped ''autogen.sh'' and similar scripts, rather use ''PKG_FIXUP:=autoreconf'' to (re)generate configure script and automake templates and encode additionally needed steps in the appropriate build recipes.+  * Never trust shipped ''autogen.sh'' and similar scripts, rather use ''PKG_FIXUP:=autoreconf'' to (re)generate the configure script and automake templates and encode additionally needed steps in the appropriate build recipes.
  
 ===== Dependencies ===== ===== Dependencies =====
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 dynamic runtime requirements. dynamic runtime requirements.
  
-//Runtime dependencies// on the other hand specify the relation of //binary packages//,+//Runtime dependencies//, on the other hand, specify the relation of //binary packages//,
 instructing the package manager to fetch and install the listed dependencies before installing instructing the package manager to fetch and install the listed dependencies before installing
 the binary package itself. A //runtime dependency// automatically implies a //build  the binary package itself. A //runtime dependency// automatically implies a //build 
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 ==== ABI Version ==== ==== ABI Version ====
  
-Setting an ''ABI_VERSION'' variable on a library package definition will cause the buildsystem+Setting an ''ABI_VERSION'' variable on a library package definition will cause the build system
 to track the value of this variable and trigger recompilations in all packages depending on to track the value of this variable and trigger recompilations in all packages depending on
 this library package whenever the value is incremented. This is useful to force re-linking of  this library package whenever the value is incremented. This is useful to force re-linking of 
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 Example: when ''libfoo'' is updated to a new, incompatible version and its ''SONAME'' property Example: when ''libfoo'' is updated to a new, incompatible version and its ''SONAME'' property
 changed from ''libfoo.so.1.0'' to ''libfoo.so.1.1'', then ''ABI_VERSION'' should be increased changed from ''libfoo.so.1.0'' to ''libfoo.so.1.1'', then ''ABI_VERSION'' should be increased
-from ''1.0'' to ''1.1'', causing the resulting ''liboo'' runtime package to be called+from ''1.0'' to ''1.1'', causing the resulting ''libfoo'' binary package to be called
 ''libfoo1.1''. Source packages linking ''libfoo'' from then on, will have runtime dependencies ''libfoo1.1''. Source packages linking ''libfoo'' from then on, will have runtime dependencies
 on ''libfoo1.1''. on ''libfoo1.1''.
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 When a shared library is packaged, the ''ABI_VERSION'' variable of the corresponding When a shared library is packaged, the ''ABI_VERSION'' variable of the corresponding
 ''define Package/lib...'' section should be set to the ''SONAME'' of the ''.so'' library file ''define Package/lib...'' section should be set to the ''SONAME'' of the ''.so'' library file
-contained within the binary package. The ''SONAME'' usually reflects the libraries internal+contained within the binary package. The ''SONAME'' usually reflects the library's internal
 ''ABI'' version and is incremented whenever incompatible changes to the public APIs are made ''ABI'' version and is incremented whenever incompatible changes to the public APIs are made
-within the library, e.g. when changing a function call signature or when removing exported+within the library, E.G. when changing a function call signature or when removing exported
 symbols. symbols.
  
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 ==== Development Files ==== ==== Development Files ====
  
-Source packages defining binary packages shipping shared libraries should declare a ''Build/InstallDev'' +Source packages defining binary packages that ship shared libraries should declare a ''Build/InstallDev'' 
-recipe copying all resources required to discover and link the shared libraries into the staging directory.+recipe that copies all resources required to discover and link the shared libraries into the staging directory.
  
 A typical ''InstallDev'' recipe usually copies all library symlinks (including the unversioned ones), A typical ''InstallDev'' recipe usually copies all library symlinks (including the unversioned ones),
 header files and, in case they're provided, pkg-config (''*.pc'') files. header files and, in case they're provided, pkg-config (''*.pc'') files.
  • Last modified: 2020/03/04 17:40
  • by adamkpickering