5.1. Variables Reference¶
The following variables are provided by PTXdist to simplify creating rule files. Every developer should use these variables in every single line in the rule file to avoid any further adaption when external paths are changed.
To get their content related to the current project, we can simply run a:
$ ptxdist print PTXDIST_TOPDIR /usr/local/lib/ptxdist-2022.09.0
PTXDIST_TOPDIR with one of the other generic variables
- Points always to the installation directory of PTXdist.
- Everything that references
PTXDIST_WORKSPACEwill use the active projects’s folder.
PTXDIST_SYSROOT_CROSSpoints to a directory tree all cross relevant executables, libraries and header files are installed to in the current project. All of the project’s packages built for the host to create data for the target are searching in this directory tree for their dependencies (executables, header and library files). Use
$(PTXDIST_SYSROOT_CROSS)/binto install executables,
$(PTXDIST_SYSROOT_CROSS)/includefor header files and
PTXDIST_SYSROOT_HOSTpoints to a directory tree all host relevant executables, libraries and header files are installed to. All project’s packages built for the host are searching in this directory tree for their dependencies (executables, header and library files). Use
$(PTXDIST_SYSROOT_HOST)/binto install executables,
$(PTXDIST_SYSROOT_HOST)/includefor header files and
PTXDIST_SYSROOT_TARGETpoints to a directory tree all target relevant libraries and header files are installed to. All project’s packages built for the target are searching in this directory tree for their dependencies (header and library files). These files are for compile time only (for example to link a target executable against a target library), not for run-time! Use
$(PTXDIST_SYSROOT_TARGET)/includefor header files and
Other useful variables:
Use to find cross tools. This path must be used to create anything that depends on the target’s architecture, but needs something running on the host to do the job. Examples:
- Creating a UBI image from the target’s root filesystem
- This will need a tool running on the host, but it will create data or code that runs on or is used on the target
- Building a library for the target
- If this library needs other resources to be built (other libraries)
configurefinds the right information in this path.
- Used to find host tools. This path must be used to create anything that doesn’t depend on the architecture.
ROOTDIRpoints to the root of the target’s root filesystem in the current project. Used in very rare cases (to create strange packages based on data in target’s root filesystem for example).
PTXCONF_PLATFORMexpands to the name of the currently selected platform. This name is used in various file names and paths.
PTXDIST_PLATFORMSUFFIXexpands to the name of the currently selected platform, but with a leading dot. This is used in various files PTXdist should search for.
PTXDIST_PLATFORMCONFIGDIRpoints to the directory tree of the currently selected platform. This path is used in various search functions.
PTXDIST_PLATFORMDIRpoints to the directory build tree of the currently selected platform.
PACKAGESis a list of space-separated lowercase package names that are built and installed during the PTXdist build run, and installed into the target root filesystem when building images.
-yvariant contains only those packages that are selected with
PTXCONF_<PKG>=y, while the
-mvariant contains only those which are selected with
PTXCONF_<PKG>=m(used for collections). A target package rule usually adds its name to one of those variables if it has been selected. The union of those two sets then ends up in
- In analogy to
PACKAGES, target packages that are added to these lists will be built normally during the build run. In contrast however, they are not installed into a root filesystem by default when building images, and image rules must request them explicitly. This is useful for specialized packages that are only needed for specific images, see Creating Individual Root-Filesystems for each Variant.
- Similar to
PACKAGES, these variables contain the host and cross packages that are built and installed during the PTXdist build run. There are analogous
-mvariants of those variables too.
Package Specific Variables¶
For the following variables
<PKG> is a placeholder for the package
name. It is also the Kconfig symbol name (without the
- This is the name of the package including version. For most packages,
this is the name of the source archive (without suffix) and the source
directory. PTXdist will search for patches in a directory with this name.
This is usually defined as
<name>-$(<PKG>_VERSION). This variable is required for most packages. The only exception are packages that only install some files in the targetinstall stage (e.g. from projectroot/).
- The version of the package. It is used as the version for the ipk packages. As such, it is required for all packages that create such packages. Most target packages fall in this category.
- The md5 checksum of the source archive. PTXdist calculates the checksum before extracting the archive and will abort if does not match. Upstream project occasionally change the content of an archive without releasing a new version. This check helps to ensure that all developers work with the same source code.
- The archive suffix without the leading ‘.’, e.g. ‘tar.gz’ or ‘zip’. This
is only used locally to define
This is the download URL for the source archive. It is a space separated list of URLs. PTXdist will try each URL until it finds one that works. There are two main reasons to provide more than one URL: 1. Additional mirror(s) in case the main location is unavailable. 2. Some projects move old versions into a separate directory when a new version is released. Providing both versions of the URL ensures that PTXdist still has a working URL after the next upstream release.
URLs can have options. Options are appended to the URL separated by ‘;’. For normal downloads the following options are supported:
no-check-certificateto indicate that SSL certificate checking should be disabled.
no-proxyto disable any configured proxy.
cookie:<value>to specify a cookie that should be sent.
Files in the local filesystem can be addressed with
file://URLs. In this case, the URL can also point to a directory. In this case
<PKG>_DIRwill be a symlink to the specified directory. ‘lndir://’ can be used to create a shadow copy instead. For locations inside the BSP the URL should use
$(PTXDIST_WORKSPACE)to define the correct absolute path.
If no source archive is available, PTXdist can get the source from revision control systems. ‘git’ and ‘svn’ are currently supported. Note that this cannot be used to follow a branch! PTXdist will create the archive defined
<PKG>_SOURCEand use it if available.
Git URLs must either start with ‘git://’ or end with ‘.git’. They have a mandatory
Svn URLs must start with ‘svn://’. They have a mandatory
The location of the downloaded source archive. There should be no reason to set this to anything other than
For local URLs (
<PKG>_SOURCEmust not be set.
The name of the patch directory, relative to any of the paths listed in
PTXDIST_PATH_PATCHES(i.e., according to the search order described in Patching Packages). If not specified, the default patch directory name is set to the value of the
This variable can be set for multiple packages that should share the same patch stack (e.g. kernel packages).
- This is the directory where the source archive is extracted. In most
cases this is set to
$(BUILDDIR)/$(<PKG>). However, if two packages use the same source archive, then something else must be used to make sure that they use different directories. See the rules for ‘gdb’ and ‘gdbserver’ for an example.
The license of the package in the form of an SPDX license expression. The following values have special meaning for PTXdist:
custom-exception: for licenses or license exceptions that are considered free software, but do not match any license or license exception known to SPDX.
proprietary: for proprietary (non-free) packages
ignorefor packages without their own license, e.g. meta packages or packages that only install files from
unknown: no licensing information was extracted yet
See the section Tracking licensing information in packages for more information.
- A space separated list of URLs of license text files. The URLs must be
file://URLs relative to
<PKG>_DIR. Absolute URLs using
$(PTXDIST_WORKSPACE)can be used in case the license text is missing in the upstream archive. Arguments are appended with ‘;’ as separator. The
md5=<md5sum>argument is mandatory. It defines the md5 checksum of the full license text.
startline=<number>;endline=<number>can be used in case the specified file contains more than just the license text, e.g. if the license is in the header of a source file. For non ASCII or UTF-8 files the encoding can be specified with
encoding=<enc>. See the section Tracking licensing information in packages for more information.
For most packages the variables described above are undefined by default. However, for cross and host packages these variables default to the value of the corresponding target package if it exists.
- This variable specifies a configuration file of some kind for the
packages. For packages with
kconfigthe variable must specify an absolute path to the kconfig file. For image packages that use genimage, PTXdist will look for
config/images/$(<PKG>_CONFIG)in the BSP and PTXdist in the usual search order.
When PTXdist extracts source archives, it will create
<PKG>_DIRfirst and then extracts the archive there. If
<PKG>_STRIP_LEVELis set to 1 (the default) then PTXdist removes the first directory level defined inside the archive. For most packages that this is the same as just extracting the archive. However, this is useful for packages with badly named top-level directories or packages where the directory must be renamed to avoid collisions (e.g. gdbserver).
The main use-case for
<PKG>_STRIP_LEVELis to set it to 0 for packages without a top-level directory.
<PKG>_STRIP_LEVELcould be set to 2 or more to remove more than one directory level.
If this is set to
YESthen PTXdist will build the package out of tree. This is only supported for autoconf, qmake and cmake packages. The default is
YESfor cmake packages and
NOfor everything else. It will use
$(<PKG>_DIR)-buildas build directory.
This is especially useful for
file://URLS that point to directories to keep the source tree free of build files.
KEEPcan be used instead of
YES. In this case the build tree is not deleted at the beginning of the prepare stage. This make reconfiguration faster. This should only be used for packages that can handle configuration changes correctly and rebuild everything as needed.
- This is a directory relative to
<PKG>_DIR. If set, all build operations are executed in this directory instead. By default
<PKG>_SUBDIRis undefined so all operations are executed in the top-level directory.
Build Environment for all Stages¶
- This variable defines the PATH used by all build stages. It is evaluated
as is, so it must start with
PATH=. If undefined, PTXdist will use
PATH=$(CROSS_PATH)for target packages
PATH=$(HOST_PATH)for host packages and
PATH=$(HOST_CROSS_PATH)for cross packages. It must be set by packages that use the variable locally in the make file or if more directories are added, e.g. to
PATH=$(PTXDIST_SYSROOT_CROSS)/bin/qt5:$(CROSS_PATH)for packages that use qmake from Qt5.
- Compiler, preprocessor and linker are never called directly in PTXdist.
Instead, wrapper scripts are called that expand the command line before
calling the actual tool. These variables can be used to influence these
wrappers. The specified flags are added to the command line when
appropriate. In most cases this it the preferred way to add additional
flags. Adding them via environment variables or
makearguments can have unexpected side effects, such as as overwriting existing defaults.
- A list of arbitrary flags. If any one of these flags is found as an argument to the compiler, preprocessor or linker then the call will fail. This is useful to prevent implicit dependencies: Many packages try to link to libraries at configure time and use them if it works. Adding ‘-l<lib>’ to the blacklist makes it possible to prevent such a detection and explicitly avoid the dependency.
- PTXdist has several options in the platformconfig that inject options in
the compiler command line. This is used, for example, to add hardening
options or change the debug options. This can occasionally cause problems
for packages that use the compiler in certain ways, such as the Linux
kernel or various bootloaders. With this variable a package can disable
individual options by setting it to a space separated list of the
corresponding Kconfig symbols (without the
- The environment for the prepare stage. If undefined, PTXdist will use
$(CROSS_ENV)for target packages,
$(HOST_ENV)for host packages and
$(HOST_CROSS_ENV)for cross packages. It must be set by packages that use the variable locally in the make file or if extra variables are added. In this case the definition should start with the default value.
This variable defines what tool is used to configure the package in the prepare stage. Possible values are:
NOto do nothing in the prepare stage.
autoconffor packages that use autoconf
qmakefor qmake based packages. Note: the required Qt version must be selected.
cmakefor cmake based packages. Note
HOST_CMAKEmust be selected to ensure, that cmake is available for configuration.
kconfigfor kconfig based packages. Note
<PKG>_CONFIGmust be set as described above.
perlfor perl modules.
python3for Python packages with a normal setup.py.
This variable adds arguments to the command-line of the configuration tool. If undefined, PTXdist will use a default value that depends on the configuration tool of the package. This default value should also be used when adding additional options. The following defaults exist:
$(HOST_CROSS_AUTOCONF)for target/host/cross packages.
$(HOST_CMAKE_OPT)for target/host packages. Cross packages cannot be built with cmake
$(CROSS_QMAKE_OPT)for host packages. Host and cross packages cannot be built with qmake.
All other configuration tools have no default options. This variable is ignored for kconfig and python/python3.
- This variables defines additional environment variables for the compile
stage. In most cases this variable remains undefined because all
necessary defines are picked up in the prepare stage. For python/python3
packages PTXdist will use the default value from
<PKG>_CONF_ENV. For packages without configuration tool this must be set correctly, usually based on the
<PKG>_CONF_ENVdefault values, e,g.
$(CROSS_ENV)for target packages.
- This variables defines additional parameters to be forwarded to
makein order to build the package. It defaults to nothing to let
maketraditionally build the first defined target.
- This variables informs PTXdist, if this package can be built in parallel. Some
(mostly very smart selfmade) buildsystems fail doing so. In this case this
variable can be set to
NO. PTXdist will then build this package with one CPU only. The default is, to build packages in parallel.
- This variable defaults to
installwhich is used as a target for
make. It can be overwritten if the package needs a special target to install its results.
- This variable must not be set by the user. It defines package
install directory. All files will be installed relative to this
directory. It can be used by manual install stages. It is defined as
$(PKGDIR)/$(<PKG>)which expands to
<platform-dir>/packages/foo-1.1.0on our foo example.
The targetinstall stage has no additional variables.
Image packages use a different set of variables. They have the same
<PKG>_DIR variables as other packages, but the rest is
- This is the filename of the image that is created by the rule. This is
- This is a list of tar balls that are extracted to generate the content of the image. PTXdist will add the necessary dependencies to these files to recreate the image as needed. If a tar ball is created by another PTXdist package then this package should be selected in the menu file.
This is another mechanism to add files to the image. It can be uses instead of or in addition to
<PKG>_FILES. It must be set to a list of ptxdist packages (the lowercase name of the packages). PTXdist will add the necessary dependencies.
Note that this will not ensure that the packages are enabled or that all all package dependencies are satisfied.
$(PTX_PACKAGES_INSTALL)can be used to specify all enabled packages. Or
$(call ptx/collection, $(PTXDIST_WORKSPACE)/configs/<collection-file-name>)can be uses to to specify the packages enabled by this collection. In both cases
=must be uses instead of
:=due to the makefile include order.
genimagepackages use this to specify the
genimageconfiguration file. PTXdist will search for the specified file name in
config/images/in the BSP, platform and PTXdist in the usual search order.
- If this is set to
YESthen PTXdist will create a special nfsroot directory that contains only the files from the packages specified in
<PKG>_PKGS. This is useful if the normal nfsroot directory contains conflicting files from multiple images. The created nfsroot directory is
- This is a tar label to put on an image. This is supported by
image-root-tgzand images created with the