Table of Contents
This chapter lists common variables used in the OpenEmbedded build system and gives an overview of their function and contents.
A B C D E F G H I K L M O P Q R S T U W
Specifies if an output package should still be produced if it is empty.
By default, BitBake does not produce empty packages.
This default behavior can cause issues when there is an
RDEPENDS
or
some other hard runtime requirement on the existence of the package.
Like all package-controlling variables, you must always use them in conjunction with a package name override, as in:
ALLOW_EMPTY_${PN} = "1" ALLOW_EMPTY_${PN}-dev = "1" ALLOW_EMPTY_${PN}-staticdev = "1"
Lists commands in a package that need an alternative binary naming scheme. Sometimes the same command is provided in multiple packages. When this occurs, the OpenEmbedded build system needs to use the alternatives system to create a different binary naming scheme so the commands can co-exist.
To use the variable, list out the package's commands
that also exist as part of another package.
For example, if the busybox
package
has four commands that also exist as part of another
package, you identify them as follows:
ALTERNATIVE_busybox = "sh sed test bracket"
For more information on the alternatives system, see the
"update-alternatives.bbclass
"
section.
Used by the alternatives system to map duplicated commands
to actual locations.
For example, if the bracket
command
provided by the busybox
package is
duplicated through another package, you must use the
ALTERNATIVE_LINK_NAME
variable to
specify the actual location:
ALTERNATIVE_LINK_NAME[bracket] = "/usr/bin/["
In this example, the binary for the
bracket
command (i.e.
[
) from the
busybox
package resides in
/usr/bin/
.
ALTERNATIVE_LINK_NAME
is not
defined, it defaults to
${bindir}/<name>
.
For more information on the alternatives system, see the
"update-alternatives.bbclass
"
section.
Used by the alternatives system to create default priorities for duplicated commands. You can use the variable to create a single default regardless of the command name or package, a default for specific duplicated commands regardless of the package, or a default for specific commands tied to particular packages. Here are the available syntax forms:
ALTERNATIVE_PRIORITY = "<priority>" ALTERNATIVE_PRIORITY[<name>] = "<priority>" ALTERNATIVE_PRIORITY_<pkg>[<name>] = "<priority>"
For more information on the alternatives system, see the
"update-alternatives.bbclass
"
section.
Used by the alternatives system to create default link locations for duplicated commands. You can use the variable to create a single default location for all duplicated commands regardless of the command name or package, a default for specific duplicated commands regardless of the package, or a default for specific commands tied to particular packages. Here are the available syntax forms:
ALTERNATIVE_TARGET = "<target>" ALTERNATIVE_TARGET[<name>] = "<target>" ALTERNATIVE_TARGET_<pkg>[<name>] = "<target>"
If ALTERNATIVE_TARGET
is not
defined, it inherits the value from the
ALTERNATIVE_LINK_NAME
variable.
If ALTERNATIVE_LINK_NAME
and
ALTERNATIVE_TARGET
are the
same, the target for
ALTERNATIVE_TARGET
has ".{BPN}
" appended to it.
Finally, if the file referenced has not been
renamed, the alternatives system will rename it to
avoid the need to rename alternative files in the
do_install
task while
retaining support for the command if necessary.
For more information on the alternatives system, see the
"update-alternatives.bbclass
"
section.
An override list of append strings for each
LABEL
.
See the
grub-efi
class for more information on how this variable is used.
The email address used to contact the original author or authors in order to send patches and forward bugs.
Enables creating an automatic menu.
You must set this in your recipe.
The
syslinux
class checks this variable.
When SRCREV
is set to the value of this variable, it specifies to use the latest
source revision in the repository.
Here is an example:
SRCREV = "${AUTOREV}"
The directory within the
Build Directory
in which the OpenEmbedded build system places generated
objects during a recipe's build process.
By default, this directory is the same as the S
directory, which is defined as:
S = "${WORKDIR}/${BP}/"
You can separate the (S
) directory
and the directory pointed to by the B
variable.
Most Autotools-based recipes support separating these
directories.
The build system defaults to using separate directories for
gcc
and some kernel recipes.
Lists "recommended-only" packages to not install.
Recommended-only packages are packages installed only
through the
RRECOMMENDS
variable.
You can prevent any of these "recommended" packages from
being installed by listing them with the
BAD_RECOMMENDATIONS
variable:
BAD_RECOMMENDATIONS = "<package_name> <package_name> <package_name> ..."
You can set this variable globally in your
local.conf
file or you can attach it to
a specific image recipe by using the recipe name override:
BAD_RECOMMENDATIONS_pn-<target_image> = "<package_name>"
It is important to realize that if you choose to not install
packages using this variable and some other packages are
dependent on them (i.e. listed in a recipe's
RDEPENDS
variable), the OpenEmbedded build system ignores your
request and will install the packages to avoid dependency
errors.
Support for this variable exists only when using the IPK and RPM packaging backend. Support does not exist for DEB.
See the
NO_RECOMMENDATIONS
and the
PACKAGE_EXCLUDE
variables for related information.
Defines how BitBake handles situations where an append
file (.bbappend
) has no
corresponding recipe file (.bb
).
This condition often occurs when layers get out of sync
(e.g. oe-core
bumps a
recipe version and the old recipe no longer exists and the
other layer has not been updated to the new version
of the recipe yet).
The default fatal behavior is safest because it is the sane reaction given something is out of sync. It is important to realize when your changes are no longer being applied.
You can change the default behavior by setting this
variable to "1", "yes", or "true"
in your local.conf
file, which is
located in the
Build Directory:
Here is an example:
BB_DANGLINGAPPENDS_WARNONLY = "1"
Monitors disk space and available inodes during the build and allows you to control the build based on these parameters.
Disk space monitoring is disabled by default.
To enable monitoring, add the BB_DISKMON_DIRS
variable to your conf/local.conf
file found in the
Build Directory.
Use the following form:
BB_DISKMON_DIRS = "<action>,<dir>,<threshold> [...]" where: <action> is: ABORT: Immediately abort the build when a threshold is broken. STOPTASKS: Stop the build after the currently executing tasks have finished when a threshold is broken. WARN: Issue a warning but continue the build when a threshold is broken. Subsequent warnings are issued as defined by the BB_DISKMON_WARNINTERVAL variable, which must be defined in the conf/local.conf file. <dir> is: Any directory you choose. You can specify one or more directories to monitor by separating the groupings with a space. If two directories are on the same device, only the first directory is monitored. <threshold> is: Either the minimum available disk space, the minimum number of free inodes, or both. You must specify at least one. To omit one or the other, simply omit the value. Specify the threshold using G, M, K for Gbytes, Mbytes, and Kbytes, respectively. If you do not specify G, M, or K, Kbytes is assumed by default. Do not use GB, MB, or KB.
Here are some examples:
BB_DISKMON_DIRS = "ABORT,${TMPDIR},1G,100K WARN,${SSTATE_DIR},1G,100K" BB_DISKMON_DIRS = "STOPTASKS,${TMPDIR},1G" BB_DISKMON_DIRS = "ABORT,${TMPDIR},,100K"
The first example works only if you also provide
the BB_DISKMON_WARNINTERVAL
variable
in the conf/local.conf
.
This example causes the build system to immediately
abort when either the disk space in ${TMPDIR}
drops
below 1 Gbyte or the available free inodes drops below
100 Kbytes.
Because two directories are provided with the variable, the
build system also issue a
warning when the disk space in the
${SSTATE_DIR}
directory drops
below 1 Gbyte or the number of free inodes drops
below 100 Kbytes.
Subsequent warnings are issued during intervals as
defined by the BB_DISKMON_WARNINTERVAL
variable.
The second example stops the build after all currently
executing tasks complete when the minimum disk space
in the ${TMPDIR}
directory drops below 1 Gbyte.
No disk monitoring occurs for the free inodes in this case.
The final example immediately aborts the build when the
number of free inodes in the ${TMPDIR}
directory
drops below 100 Kbytes.
No disk space monitoring for the directory itself occurs
in this case.
Defines the disk space and free inode warning intervals.
To set these intervals, define the variable in your
conf/local.conf
file in the
Build Directory.
If you are going to use the
BB_DISKMON_WARNINTERVAL
variable, you must
also use the
BB_DISKMON_DIRS
variable
and define its action as "WARN".
During the build, subsequent warnings are issued each time
disk space or number of free inodes further reduces by
the respective interval.
If you do not provide a BB_DISKMON_WARNINTERVAL
variable and you do use BB_DISKMON_DIRS
with
the "WARN" action, the disk monitoring interval defaults to
the following:
BB_DISKMON_WARNINTERVAL = "50M,5K"
When specifying the variable in your configuration file, use the following form:
BB_DISKMON_WARNINTERVAL = "<disk_space_interval>,<disk_inode_interval>" where: <disk_space_interval> is: An interval of memory expressed in either G, M, or K for Gbytes, Mbytes, or Kbytes, respectively. You cannot use GB, MB, or KB. <disk_inode_interval> is: An interval of free inodes expressed in either G, M, or K for Gbytes, Mbytes, or Kbytes, respectively. You cannot use GB, MB, or KB.
Here is an example:
BB_DISKMON_DIRS = "WARN,${SSTATE_DIR},1G,100K" BB_DISKMON_WARNINTERVAL = "50M,5K"
These variables cause the OpenEmbedded build system to
issue subsequent warnings each time the available
disk space further reduces by 50 Mbytes or the number
of free inodes further reduces by 5 Kbytes in the
${SSTATE_DIR}
directory.
Subsequent warnings based on the interval occur each time
a respective interval is reached beyond the initial warning
(i.e. 1 Gbytes and 100 Kbytes).
Causes tarballs of the Git repositories to be placed in the
DL_DIR
directory.
For performance reasons, creating and placing tarballs of
the Git repositories is not the default action by the
OpenEmbedded build system.
BB_GENERATE_MIRROR_TARBALLS = "1"
Set this variable in your local.conf
file in the
Build Directory.
The maximum number of tasks BitBake should run in parallel at any one time. If your host development system supports multiple cores, a good rule of thumb is to set this variable to twice the number of cores.
Allows you to extend a recipe so that it builds variants of the software.
Common variants for recipes exist such as "natives" like quilt-native
,
which is a copy of Quilt built to run on the build system;
"crosses" such as gcc-cross
,
which is a compiler built to run on the build machine but produces binaries
that run on the target MACHINE
;
"nativesdk", which targets the SDK machine instead of MACHINE
;
and "mulitlibs" in the form "multilib:<multilib_name>
".
To build a different variant of the recipe with a minimal amount of code, it usually is as simple as adding the following to your recipe:
BBCLASSEXTEND =+ "native nativesdk" BBCLASSEXTEND =+ "multilib:<multilib_name>"
Lists the names of configured layers.
These names are used to find the other BBFILE_*
variables.
Typically, each layer will append its name to this variable in its
conf/layer.conf
file.
Variable that expands to match files from
BBFILES
in a particular layer.
This variable is used in the conf/layer.conf
file and must
be suffixed with the name of the specific layer (e.g.
BBFILE_PATTERN_emenlow
).
Assigns the priority for recipe files in each layer.
This variable is useful in situations where the same recipe appears in
more than one layer.
Setting this variable allows you to prioritize a
layer against other layers that contain the same recipe - effectively
letting you control the precedence for the multiple layers.
The precedence established through this variable stands regardless of a
recipe's version
(PV
variable).
For example, a layer that has a recipe with a higher PV
value but for
which the BBFILE_PRIORITY
is set to have a lower precedence still has a
lower precedence.
A larger value for the BBFILE_PRIORITY
variable results in a higher
precedence.
For example, the value 6 has a higher precedence than the value 5.
If not specified, the BBFILE_PRIORITY
variable is set based on layer
dependencies (see the
LAYERDEPENDS
variable for
more information.
The default priority, if unspecified
for a layer with no dependencies, is the lowest defined priority + 1
(or 1 if no priorities are defined).
bitbake-layers show-layers
to list
all configured layers along with their priorities.
List of recipe files used by BitBake to build software.
Variable that controls how BitBake displays logs on build failure.
Lists the layers to enable during the build.
This variable is defined in the bblayers.conf
configuration
file in the Build Directory.
Here is an example:
BBLAYERS = " \ /home/scottrif/poky/meta \ /home/scottrif/poky/meta-yocto \ /home/scottrif/poky/meta-yocto-bsp \ /home/scottrif/poky/meta-mykernel \ " BBLAYERS_NON_REMOVABLE ?= " \ /home/scottrif/poky/meta \ /home/scottrif/poky/meta-yocto \ "
This example enables four layers, one of which is a custom, user-defined layer
named meta-mykernel
.
Lists core layers that cannot be removed from the
bblayers.conf
file during a build
using the
Hob.
In order for BitBake to build your image using Hob, your
bblayers.conf
file must include the
meta
and meta-yocto
core layers.
Here is an example that shows these two layers listed in
the BBLAYERS_NON_REMOVABLE
statement:
BBLAYERS = " \ /home/scottrif/poky/meta \ /home/scottrif/poky/meta-yocto \ /home/scottrif/poky/meta-yocto-bsp \ /home/scottrif/poky/meta-mykernel \ " BBLAYERS_NON_REMOVABLE ?= " \ /home/scottrif/poky/meta \ /home/scottrif/poky/meta-yocto \ "
Prevents BitBake from processing recipes and recipe
append files.
Use the BBMASK
variable from within the
conf/local.conf
file found
in the
Build Directory.
You can use the BBMASK
variable
to "hide" these .bb
and
.bbappend
files.
BitBake ignores any recipe or recipe append files that
match the expression.
It is as if BitBake does not see them at all.
Consequently, matching files are not parsed or otherwise
used by BitBake.
The value you provide is passed to Python's regular expression compiler. The expression is compared against the full paths to the files. For complete syntax information, see Python's documentation at http://docs.python.org/release/2.3/lib/re-syntax.html.
The following example uses a complete regular expression
to tell BitBake to ignore all recipe and recipe append
files in the meta-ti/recipes-misc/
directory:
BBMASK = "meta-ti/recipes-misc/"
If you want to mask out multiple directories or recipes, use the vertical bar to separate the regular expression fragments. This next example masks out multiple directories and individual recipes:
BBMASK = "meta-ti/recipes-misc/|meta-ti/recipes-ti/packagegroup/" BBMASK .= "|.*meta-oe/recipes-support/" BBMASK .= "|.*openldap" BBMASK .= "|.*opencv" BBMASK .= "|.*lzma"
Notice how the vertical bar is used to append the fragments.
Used by BitBake to locate
.bbclass
and configuration files.
This variable is analogous to the
PATH
variable.
BBPATH
to point to the
Build Directory.
Set the variable as you would any environment variable
and then run BitBake:
$ BBPATH = "<build_directory>" $ export BBPATH $ bitbake <target>
Points to the server that runs memory-resident BitBake.
This variable is set by the
oe-init-build-env-memres
setup script and should not be hand-edited.
The variable is only used when you employ memory-resident
BitBake.
The setup script exports the value as follows:
export BBSERVER=localhost:$port
For more information on how the
BBSERVER
is used, see the
oe-init-build-env-memres
script, which
is located in the
Source Directory.
When inheriting binconfig.bbclass
from a recipe, this variable specifies a wildcard for
configuration scripts that need editing.
The scripts are edited to correct any paths that have been
set up during compilation so that they are correct for
use when installed into the sysroot and called by the
build processes of other recipes.
For more information on how this variable works, see
meta/classes/binconfig.bbclass
in the
Source Directory.
You can also find general information on the class in the
"binconfig.bbclass
"
section.
The base recipe name and version but without any special
recipe name suffix (i.e. -native
, lib64-
,
and so forth).
BP
is comprised of the following:
${BPN}-${PV}
The bare name of the recipe.
This variable is a version of the PN
variable
but removes common suffixes such as "-native" and "-cross" as well
as removes common prefixes such as multilib's "lib64-" and "lib32-".
The exact list of suffixes removed is specified by the
SPECIAL_PKGSUFFIX
variable.
The exact list of prefixes removed is specified by the
MLPREFIX
variable.
Prefixes are removed for multilib
and nativesdk
cases.
Specifies a URL for an upstream bug tracking website for a recipe. The OpenEmbedded build system does not use this variable. Rather, the variable is a useful pointer in case a bug in the software being built needs to be manually reported.
Points to the location of the
Build Directory.
You can define this directory indirectly through the
oe-init-build-env
and
oe-init-build-env-memres
scripts by passing in a Build Directory path when you run
the scripts.
If you run the scripts and do not provide a Build Directory
path, the BUILDDIR
defaults to
build
in the current directory.
Points to the location of the directory that holds build
statistics when you use and enable the
buildstats
class.
The BUILDSTATS_BASE
directory defaults
to
${
TMPDIR
}/buildstats/
.
For the BusyBox recipe, specifies whether to split the
output executable file into two parts: one for features
that require setuid root
, and one for
the remaining features (i.e. those that do not require
setuid root
).
The BUSYBOX_SPLIT_SUID
variable
defaults to "1", which results in a single output
executable file.
Set the variable to "0" to split the output file.
Flags passed to the C compiler for the target system.
This variable evaluates to the same as
TARGET_CFLAGS
.
An internal variable specifying the special class override that should currently apply (e.g. "class-target", "class-native", and so forth). The classes that use this variable set it to appropriate values.
You do not normally directly interact with this variable.
The value for the CLASSOVERRIDE
variable goes into
OVERRIDES
and then can be used as an override.
Here is an example where "python-native" is added to
DEPENDS
only when building for the native case:
DEPENDS_append_class-native = " python-native"
Provides a list of hardware features that are enabled in
both
MACHINE_FEATURES
and
DISTRO_FEATURES
.
This select list of features contains features that make
sense to be controlled both at the machine and distribution
configuration level.
For example, the "bluetooth" feature requires hardware
support but should also be optional at the distribution
level, in case the hardware supports Bluetooth but you
do not ever intend to use it.
For more information, see the
MACHINE_FEATURES
and DISTRO_FEATURES
variables.
Points to meta/files/common-licenses
in the
Source Directory,
which is where generic license files reside.
A regular expression that resolves to one or more hosts
(when the recipe is native) or one or more targets (when
the recipe is non-native) with which a recipe is compatible.
The regular expression is matched against
HOST_SYS
.
You can use the variable to stop recipes from being built
for classes of systems with which the recipes are not
compatible.
Stopping these builds is particularly useful with kernels.
The variable also helps to increase parsing speed
since the build system skips parsing recipes not
compatible with the current system.
A regular expression that resolves to one or more
target machines with which a recipe is compatible.
The regular expression is matched against
MACHINEOVERRIDES
.
You can use the variable to stop recipes from being built
for machines with which the recipes are not compatible.
Stopping these builds is particularly useful with kernels.
The variable also helps to increase parsing speed
since the build system skips parsing recipes not
compatible with the current machine.
Defines wildcards to match when installing a list of
complementary packages for all the packages explicitly
(or implicitly) installed in an image.
The resulting list of complementary packages is associated
with an item that can be added to
IMAGE_FEATURES
.
An example usage of this is the "dev-pkgs" item that when
added to IMAGE_FEATURES
will
install -dev packages (containing headers and other
development files) for every package in the image.
To add a new feature item pointing to a wildcard, use a variable flag to specify the feature item name and use the value to specify the wildcard. Here is an example:
COMPLEMENTARY_GLOB[dev-pkgs] = '*-dev'
Identifies editable or configurable files that are part of a package.
If the Package Management System (PMS) is being used to update
packages on the target system, it is possible that
configuration files you have changed after the original installation
and that you now want to remain unchanged are overwritten.
In other words, editable files might exist in the package that you do not
want reset as part of the package update process.
You can use the CONFFILES
variable to list the files in the
package that you wish to prevent the PMS from overwriting during this update process.
To use the CONFFILES
variable, provide a package name
override that identifies the resulting package.
Then, provide a space-separated list of files.
Here is an example:
CONFFILES_${PN} += "${sysconfdir}/file1 \ ${sysconfdir}/file2 ${sysconfdir}/file3"
A relationship exists between the CONFFILES
and
FILES
variables.
The files listed within CONFFILES
must be a subset of
the files listed within FILES
.
Because the configuration files you provide with CONFFILES
are simply being identified so that the PMS will not overwrite them,
it makes sense that
the files must already be included as part of the package through the
FILES
variable.
CONFFILES
variable,
it is good practice to use appropriate path variables.
For example, ${sysconfdir}
rather than
/etc
or ${bindir}
rather
than /usr/bin
.
You can find a list of these variables at the top of the
meta/conf/bitbake.conf
file in the
Source Directory.
A list of files that contains autoconf
test results relevant
to the current build.
This variable is used by the Autotools utilities when running
configure
.
When a recipe inherits the
distro_features_check
class, this
variable identifies distribution features that would
be in conflict should the recipe
be built.
In other words, if the
CONFLICT_DISTRO_FEATURES
variable
lists a feature that also appears in
DISTRO_FEATURES
within the
current configuration, an error occurs and the
build stops.
Specifies the list of packages to be added to the image.
You should only set this variable in the
local.conf
configuration file found
in the
Build Directory.
This variable replaces POKY_EXTRA_INSTALL
, which is no longer supported.
Specifies the parent directory of the OpenEmbedded
Core Metadata layer (i.e. meta
).
It is an important distinction that
COREBASE
points to the parent of this
layer and not the layer itself.
Consider an example where you have cloned the Poky Git
repository and retained the poky
name for your local copy of the repository.
In this case, COREBASE
points to
the poky
folder because it is the
parent directory of the poky/meta
layer.
The destination directory.
The date and time on which the current build started. The format is suitable for timestamps.
Specifies to build packages with debugging information.
This influences the value of the
SELECTED_OPTIMIZATION
variable.
The options to pass in
TARGET_CFLAGS
and CFLAGS
when compiling
a system for debugging.
This variable defaults to "-O -fno-omit-frame-pointer ${DEBUG_FLAGS} -pipe".
Specifies a weak bias for recipe selection priority.
The most common usage of this is variable is to set
it to "-1" within a recipe for a development version of a
piece of software.
Using the variable in this way causes the stable version
of the recipe to build by default in the absence of
PREFERRED_VERSION
being used to build the development version.
DEFAULT_PREFERENCE
is weak and is overridden by
BBFILE_PRIORITY
if that variable is different between two layers
that contain different versions of the same recipe.
Lists a recipe's build-time dependencies (i.e. other recipe files). The system ensures that all the dependencies listed have been built and have their contents in the appropriate sysroots before the recipe's configure task is executed.
Consider this simple example for two recipes named "a" and
"b" that produce similarly named packages.
In this example, the DEPENDS
statement appears in the "a" recipe:
DEPENDS = "b"
Here, the dependency is such that the
do_configure
task for recipe "a"
depends on the do_populate_sysroot
task of recipe "b".
This means anything that recipe "b" puts into sysroot
is available when recipe "a" is configuring itself.
For information on runtime dependencies, see the
RDEPENDS
variable.
Points to the general area that the OpenEmbedded build
system uses to place images, packages, SDKs and other output
files that are ready to be used outside of the build system.
By default, this directory resides within the
Build Directory
as ${TMPDIR}/deploy
.
For more information on the structure of the Build
Directory, see
"The Build Directory - build/
"
section.
For more detail on the contents of the
deploy
directory, see the
"Images" and
"Application Development SDK"
sections.
Points to the area that the OpenEmbedded build system uses
to place images and other associated output files that are
ready to be deployed onto the target machine.
The directory is machine-specific as it contains the
${MACHINE}
name.
By default, this directory resides within the
Build Directory
as ${DEPLOY_DIR}/images/${MACHINE}/
.
For more information on the structure of the Build
Directory, see
"The Build Directory - build/
"
section.
For more detail on the contents of the
deploy
directory, see the
"Images" and
"Application Development SDK"
sections.
For recipes that inherit the
deploy
class, the DEPLOYDIR
points to a
temporary work area for deployed files that is set in the
deploy
class as follows:
DEPLOYDIR = "${WORKDIR}/deploy-${PN
}"
Recipes inheriting the deploy
class
should copy files to be deployed into
DEPLOYDIR
, and the class will take
care of copying them into
DEPLOY_DIR_IMAGE
afterwards.
The package description used by package managers.
If not set, DESCRIPTION
takes
the value of the
SUMMARY
variable.
The short name of the distribution.
This variable corresponds to a distribution
configuration file whose root name is the same as the
variable's argument and whose filename extension is
.conf
.
For example, the distribution configuration file for the
Poky distribution is named poky.conf
and resides in the
meta-yocto/conf/distro
directory of
the
Source Directory.
Within that poky.conf
file, the
DISTRO
variable is set as follows:
DISTRO = "poky"
Distribution configuration files are located in a
conf/distro
directory within the
Metadata
that contains the distribution configuration.
The value for DISTRO
must not contain
spaces, and is typically all lower-case.
DISTRO
variable is blank, a set
of default configurations are used, which are specified
within
meta/conf/distro/defaultsetup.conf
also in the Source Directory.
Specifies a list of distro-specific packages to add to all images.
This variable takes affect through
packagegroup-base
so the
variable only really applies to the more full-featured
images that include packagegroup-base
.
You can use this variable to keep distro policy out of
generic images.
As with all other distro variables, you set this variable
in the distro .conf
file.
Specifies a list of distro-specific packages to add to all images if the packages exist. The packages might not exist or be empty (e.g. kernel modules). The list of packages are automatically installed but you can remove them.
The software support you want in your distribution for various features. You define your distribution features in the distribution configuration file.
In most cases, the presence or absence of a feature in
DISTRO_FEATURES
is translated to the
appropriate option supplied to the configure script
during do_configure
for recipes that
optionally support the feature.
For example, specifying "x11" in
DISTRO_FEATURES
, causes
every piece of software built for the target that can
optionally support X11 to have its X11 support enabled.
Two more examples are Bluetooth and NFS support. For a more complete list of features that ships with the Yocto Project and that you can provide with this variable, see the "Distro Features" section.
Features to be added to
DISTRO_FEATURES
if not also present in
DISTRO_FEATURES_BACKFILL_CONSIDERED
.
This variable is set in the meta/conf/bitbake.conf
file.
It is not intended to be user-configurable.
It is best to just reference the variable to see which distro features are
being backfilled for all distro configurations.
See the Feature backfilling section for
more information.
Features from
DISTRO_FEATURES_BACKFILL
that should not be backfilled (i.e. added to
DISTRO_FEATURES
)
during the build.
See the "Feature Backfilling" section for
more information.
The long name of the distribution.
Alias names used for the recipe in various Linux distributions.
See the "Handling a Package Name Alias" section in the Yocto Project Development Manual for more information.
The version of the distribution.
This variable lists overrides specific to the current
distribution.
By default, the variable list includes the value of the
DISTRO
variable.
You can extend the variable to apply any variable overrides
you want as part of the distribution and are not
already in OVERRIDES
through
some other means.
The central download directory used by the build process to
store downloads.
By default, DL_DIR
gets files
suitable for mirroring for everything except Git
repositories.
If you want tarballs of Git repositories, use the
BB_GENERATE_MIRROR_TARBALLS
variable.
You can set this directory by defining the
DL_DIR
variable in the
conf/local.conf
file.
This directory is self-maintaining and you should not have
to touch it.
By default, the directory is downloads
in the
Build Directory.
#DL_DIR ?= "${TOPDIR}/downloads"
To specify a different download directory, simply remove the comment from the line and provide your directory.
During a first build, the system downloads many different
source code tarballs from various upstream projects.
Downloading can take a while, particularly if your network
connection is slow.
Tarballs are all stored in the directory defined by
DL_DIR
and the build system looks there
first to find source tarballs.
You can safely share this directory between multiple builds on the same development machine. For additional information on how the build process gets source files when working behind a firewall or proxy server, see this specific question in the "FAQ" chapter.
Variable that controls which locales for
eglibc
are generated during the
build (useful if the target device has 64Mbytes
of RAM or less).
Specifies the quality assurance checks whose failures are
reported as errors by the OpenEmbedded build system.
You set this variable in your distribution configuration
file.
For a list of the checks you can control with this variable,
see the
"insane.bbclass
"
section.
Directs BitBake to exclude a recipe from world builds (i.e.
bitbake world
).
During world builds, BitBake locates, parses and builds all
recipes found in every layer exposed in the
bblayers.conf
configuration file.
To exclude a recipe from a world build using this variable, set the variable to "1" in the recipe.
EXCLUDE_FROM_WORLD
may still be built during a world build in order to satisfy
dependencies of other recipes.
Adding a recipe to EXCLUDE_FROM_WORLD
only ensures that the recipe is not explicitly added
to the list of build targets in a world build.
Used with file and pathnames to create a prefix for a recipe's
version based on the recipe's
PE
value.
If PE
is set and greater than zero for a recipe,
EXTENDPE
becomes that value (e.g if
PE
is equal to "1" then EXTENDPE
becomes "1_").
If a recipe's PE
is not set (the default) or is equal to
zero, EXTENDPE
becomes "".
See the STAMP
variable for an example.
The full package version specification as it appears on the final packages produced by a recipe. The variable's value is normally used to fix a runtime dependency to the exact same version of another package in the same recipe:
RDEPENDS_${PN}-additional-module = "${PN} (= ${EXTENDPKGV})"
The dependency relationships are intended to force the package manager to upgrade these types of packages in lock-step.
If externalsrc.bbclass
is inherited,
this variable points to the source tree, which is
outside of the OpenEmbedded build system.
When set, this variable sets the
S
variable, which is what the OpenEmbedded build system uses
to locate unpacked recipe source code.
For more information on
externalsrc.bbclass
, see the
"externalsrc.bbclass
"
section.
You can also find information on how to use this variable
in the
"Building Software from an External Source"
section in the Yocto Project Development Manual.
If externalsrc.bbclass
is inherited,
this variable points to the directory in which the recipe's
source code is built,
which is outside of the OpenEmbedded build system.
When set, this variable sets the
B
variable, which is what the OpenEmbedded build system uses
to locate the Build Directory.
For more information on
externalsrc.bbclass
, see the
"externalsrc.bbclass
"
section.
You can also find information on how to use this variable
in the
"Building Software from an External Source"
section in the Yocto Project Development Manual.
The list of additional features to include in an image.
Typically, you configure this variable in your
local.conf
file, which is found in the
Build Directory.
Although you can use this variable from within a recipe,
best practices dictate that you do not.
IMAGE_FEATURES
variable.
Here are some examples of features you can add:
"dbg-pkgs" - Adds -dbg packages for all installed packages including symbol information for debugging and profiling. "debug-tweaks" - Makes an image suitable for development. For example, ssh root access has a blank password. You should remove this feature before you produce a production image. "dev-pkgs" - Adds -dev packages for all installed packages. This is useful if you want to develop against the libraries in the image. "read-only-rootfs" - Creates an image whose root filesystem is read-only. See the "Creating a Read-Only Root Filesystem" section in the Yocto Project Development Manual for more information "tools-debug" - Adds debugging tools such as gdb and strace. "tools-profile" - Adds profiling tools such as oprofile, exmap, lttng and valgrind (x86 only). "tools-sdk" - Adds development tools such as gcc, make, pkgconfig and so forth. "tools-testapps" - Adds useful testing tools such as ts_print, aplay, arecord and so forth.
For a complete list of image features that ships with the Yocto Project, see the "Image Features" section.
For an example that shows how to customize your image by
using this variable, see the
"Customizing Images Using Custom IMAGE_FEATURES
and EXTRA_IMAGE_FEATURES
"
section in the Yocto Project Development Manual.
A list of recipes to build that do not provide packages for installing into the root filesystem.
Sometimes a recipe is required to build the final image but is not
needed in the root filesystem.
You can use the EXTRA_IMAGEDEPENDS
variable to
list these recipes and thus specify the dependencies.
A typical example is a required bootloader in a machine configuration.
Additional cmake
options.
Additional configure
script options.
Additional GNU make
options.
When a recipe inherits the
scons
class, this variable specifies additional configuration
options you want to pass to the
scons
command line.
Configuration variables or options you want to pass to
qmake
.
Use this variable when the arguments need to be after the
.pro
file list on the command line.
This variable is used with recipes that inherit the
qmake_base
class or other classes that inherit
qmake_base
.
Configuration variables or options you want to pass to
qmake
.
Use this variable when the arguments need to be before the
.pro
file list on the command line.
This variable is used with recipes that inherit the
qmake_base
class or other classes that inherit
qmake_base
.
When a recipe inherits the
extrausers
class, this variable provides image level user and group
operations.
This is a more global method of providing user and group
configuration as compared to using the
useradd
class, which ties user and group configurations to a
specific recipe.
The set list of commands you can configure using the
EXTRA_USERS_PARAMS
is shown in the
extrausers
class.
These commands map to the normal Unix commands of the same
names:
# EXTRA_USERS_PARAMS = "\ # useradd -p '' tester; \ # groupadd developers; \ # userdel nobody; \ # groupdel -g video; \ # groupmod -g 1020 developers; \ # usermod -s /bin/sh tester; \ # "
Points to the base URL of the server and location within
the document-root that provides the metadata and
packages required by OPKG to support runtime package
management of IPK packages.
You set this variable in your
local.conf
file.
Consider the following example:
FEED_DEPLOYDIR_BASE_URI = "http://192.168.7.1/BOARD-dir"
This example assumes you are serving your packages over
HTTP and your databases are located in a directory
named BOARD-dir
, which is underneath
your HTTP server's document-root.
In this case, the OpenEmbedded build system generates a set
of configuration files for you in your target that work
with the feed.
The list of directories or files that are placed in packages.
To use the FILES
variable, provide a package name
override that identifies the resulting package.
Then, provide a space-separated list of files or paths that identifies the
files you want included as part of the resulting package.
Here is an example:
FILES_${PN} += "${bindir}/mydir1/ ${bindir}/mydir2/myfile"
FILES
variable,
it is good practice to use appropriate path variables.
For example, use ${sysconfdir}
rather than
/etc
, or ${bindir}
rather
than /usr/bin
.
You can find a list of these variables at the top of the
meta/conf/bitbake.conf
file in the
Source Directory.
If some of the files you provide with the FILES
variable
are editable and you know they should not be
overwritten during the package update process by the Package Management
System (PMS), you can identify these files so that the PMS will not
overwrite them.
See the CONFFILES
variable for information on how to identify these files to the PMS.
Extends the search path the OpenEmbedded build system uses
when looking for files and patches as it processes recipes
and append files.
The default directories BitBake uses when it processes
recipes are initially defined by the
FILESPATH
variable.
You can extend FILESPATH
variable
by using FILESEXTRAPATHS
.
Best practices dictate that you accomplish this by using
FILESEXTRAPATHS
from within a
.bbappend
file and that you prepend
paths as follows:
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
In the above example, the build system first looks for files in a directory that has the same name as the corresponding append file.
When extending FILESEXTRAPATHS
,
be sure to use the immediate expansion
(:=
) operator.
Immediate expansion makes sure that BitBake evaluates
THISDIR
at the time the directive is encountered rather than at
some later time when expansion might result in a
directory that does not contain the files you need.
Also, include the trailing separating colon character if you are prepending. The trailing colon character is necessary because you are directing BitBake to extend the path by prepending directories to the search path.
Here is another common use:
FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
In this example, the build system extends the
FILESPATH
variable to include a
directory named files
that is in the
same directory as the corresponding append file.
Here is a final example that specifically adds three paths:
FILESEXTRAPATHS_prepend := "path_1:path_2:path_3:"
By prepending paths in .bbappend
files, you allow multiple append files that reside in
different layers but are used for the same recipe to
correctly extend the path.
A subset of OVERRIDES
used by the OpenEmbedded build system for creating
FILESPATH
.
You can find more information on how overrides are handled
in the BitBake Manual that is located at
bitbake/doc/manual
in the
Source Directory.
By default, the FILESOVERRIDES
variable is defined as:
FILESOVERRIDES = "${TRANSLATED_TARGET_ARCH}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}"
FILESOVERRIDES
variable.
The values match up with expected overrides and are
used in an expected manner by the build system.
The default set of directories the OpenEmbedded build system
uses when searching for patches and files.
During the build process, BitBake searches each directory in
FILESPATH
in the specified order when
looking for files and patches specified by each
file://
URI in a recipe.
The default value for the FILESPATH
variable is defined in the base.bbclass
class found in meta/classes
in the
Source Directory:
FILESPATH = "${@base_set_filespath(["${FILE_DIRNAME}/${BP}", \ "${FILE_DIRNAME}/${BPN}", "${FILE_DIRNAME}/files"], d)}"
FILESPATH
variable.
If you want the build system to look in directories
other than the defaults, extend the
FILESPATH
variable by using the
FILESEXTRAPATHS
variable.
Be aware that the default FILESPATH
directories do not map to directories in custom layers
where append files (.bbappend
)
are used.
If you want the build system to find patches or files
that reside with your append files, you need to extend
the FILESPATH
variable by using
the
FILESEXTRAPATHS
variable.
Allows you to define your own file permissions settings table as part of your configuration for the packaging process. For example, suppose you need a consistent set of custom permissions for a set of groups and users across an entire work project. It is best to do this in the packages themselves but this is not always possible.
By default, the OpenEmbedded build system uses the fs-perms.txt
, which
is located in the meta/files
folder in the
Source Directory.
If you create your own file permissions setting table, you should place it in your
layer or the distro's layer.
You define the FILESYSTEM_PERMS_TABLES
variable in the
conf/local.conf
file, which is found in the
Build Directory, to
point to your custom fs-perms.txt
.
You can specify more than a single file permissions setting table.
The paths you specify to these files must be defined within the
BBPATH
variable.
For guidance on how to create your own file permissions settings table file,
examine the existing fs-perms.txt
.
When a recipe inherits the
fontcache
class, this variable identifies packages containing font
files that need to be cached by Fontconfig.
By default, the fontcache
class assumes
that fonts are in the recipe's main package
(i.e. ${
PN
}
).
Use this variable if fonts you need are in a package
other than that main package.
The options to pass in
TARGET_CFLAGS
and CFLAGS
when compiling an optimized system.
This variable defaults to
"-O2 -pipe ${DEBUG_FLAGS}".
When a recipe inherits the
useradd
class, this variable
specifies for a package what parameters should be passed
to the groupadd
command
if you wish to add a group to the system when the package
is installed.
Here is an example from the dbus
recipe:
GROUPADD_PARAM_${PN} = "-r netdev"
For information on the standard Linux shell command
groupadd
, see
http://linux.die.net/man/8/groupadd.
When a recipe inherits the
useradd
class, this variable
specifies for a package what parameters should be passed
to the groupmems
command
if you wish to modify the members of a group when the
package is installed.
For information on the standard Linux shell command
groupmems
, see
http://linux.die.net/man/8/groupmems.
Configures the GNU GRand Unified Bootloader (GRUB) to have
graphics and serial in the boot menu.
Set this variable to "1" in your
local.conf
or distribution
configuration file to enable graphics and serial
in the menu.
See the
grub-efi
class for more information on how this variable is used.
Additional options to add to the GNU GRand Unified
Bootloader (GRUB) configuration.
Use a semi-colon character (;
) to
separate multiple options.
The GRUB_OPTS
variable is optional.
See the
grub-efi
class for more information on how this variable is used.
Specifies the timeout before executing the default
LABEL
in the GNU GRand Unified
Bootloader (GRUB).
The GRUB_TIMEOUT
variable is optional.
See the
grub-efi
class for more information on how this variable is used.
For recipes that inherit the
gtk-immodules-cache
class, this variable specifies the packages that contain the
GTK+ input method modules being installed when the modules
are in packages other than the main package.
Website where more information about the software the recipe is building can be found.
Specifies the system, including the architecture and the operating system, for with the build is occurring in the context of the current recipe. The OpenEmbedded build system automatically sets this variable. You do not need to set the variable yourself.
Here are two examples:
Given a native recipe on a 32-bit x86 machine running Linux, the value is "i686-linux".
Given a recipe being built for a little-endian MIPS target running Linux, the value might be "mipsel-linux".
Points to the icecc-create-env
script
that you provide.
This variable is used by the
icecc
class.
You set this variable in your
local.conf
file.
If you do not point to a script that you provide, the
OpenEmbedded build system uses the default script provided
by the icecc-create-env.bb
recipe,
which is a modified version and not the one that comes with
icecc
.
The location of the icecc
binary.
You can set this variable in your
local.conf
file.
If your local.conf
file does not define
this variable, the
icecc
class attempts to define it by locating
icecc
using which
.
Identifies user classes that you do not want the
Icecream distributed compile support to consider.
This variable is used by the
icecc
class.
You set this variable in your
local.conf
file.
When you list classes using this variable, you are "blacklisting" them from distributed compilation across remote hosts. Any classes you list will be distributed and compiled locally.
Identifies user recipes that you do not want the
Icecream distributed compile support to consider.
This variable is used by the
icecc
class.
You set this variable in your
local.conf
file.
When you list packages using this variable, you are "blacklisting" them from distributed compilation across remote hosts. Any packages you list will be distributed and compiled locally.
Identifies user recipes that use an empty
PARALLEL_MAKE
variable that you want to force remote distributed
compilation on using the Icecream distributed compile
support.
This variable is used by the
icecc
class.
You set this variable in your
local.conf
file.
The base name of image output files.
This variable defaults to the recipe name
(${
PN
}
).
A list of classes that all images should inherit. You typically use this variable to specify the list of classes that register the different types of images the OpenEmbedded build system creates.
The default value for IMAGE_CLASSES
is
image_types
.
You can set this variable in your
local.conf
or in a distribution
configuration file.
For more information, see
meta/classes/image_types.bbclass
in the
Source Directory.
The primary list of features to include in an image.
Typically, you configure this variable in an image recipe.
Although you can use this variable from your
local.conf
file, which is found in the
Build Directory,
best practices dictate that you do not.
EXTRA_IMAGE_FEATURES
variable.
For a list of image features that ships with the Yocto Project, see the "Image Features" section.
For an example that shows how to customize your image by
using this variable, see the
"Customizing Images Using Custom IMAGE_FEATURES
and EXTRA_IMAGE_FEATURES
"
section in the Yocto Project Development Manual.
Specifies the formats the OpenEmbedded build system uses
during the build when creating the root filesystem.
For example, setting IMAGE_FSTYPES
as follows causes the build system to create root
filesystems using two formats: .ext3
and .tar.bz2
:
IMAGE_FSTYPES = "ext3 tar.bz2"
For the complete list of supported image formats from which
you can choose, see
IMAGE_TYPES
.
IMAGE_FSTYPES
inside an image recipe, be sure that you do so prior to the
"inherit image" line of the recipe or the live image will
not build.
_append
or
_prepend
. To add one or more
additional options to this variable the
+=
operator must be used.
Specifies the packages to install into an image.
The IMAGE_INSTALL
variable is a mechanism for an image
recipe and you should use it with care to avoid ordering issues.
Image recipes set IMAGE_INSTALL
to specify the
packages to install into an image through image.bbclass
.
Additionally, "helper" classes exist, such as core-image.bbclass
,
that can take
IMAGE_FEATURES
lists
and turn these into auto-generated entries in
IMAGE_INSTALL
in addition to its default contents.
Using IMAGE_INSTALL
with the +=
operator from the /conf/local.conf
file or from within
an image recipe is not recommended as it can cause ordering issues.
Since core-image.bbclass
sets IMAGE_INSTALL
to a default value using the ?=
operator, using a
+=
operation against IMAGE_INSTALL
will result in unexpected behavior when used in
conf/local.conf
.
Furthermore, the same operation from within an image recipe may or may not
succeed depending on the specific situation.
In both these cases, the behavior is contrary to how most users expect
the +=
operator to work.
When you use this variable, it is best to use it as follows:
IMAGE_INSTALL_append = " package-name"
Be sure to include the space between the quotation character and the start of the package name or names.
Specifies the list of locales to install into the image
during the root filesystem construction process.
The OpenEmbedded build system automatically splits locale
files, which are used for localization, into separate
packages.
Setting the IMAGE_LINGUAS
variable
ensures that any locale packages that correspond to packages
already selected for installation into the image are also
installed.
Here is an example:
IMAGE_LINGUAS = "pt-br de-de"
In this example, the build system ensures any Brazilian
Portuguese and German locale files that correspond to
packages in the image are installed (i.e.
*-locale-pt-br
and *-locale-de-de
as well as
*-locale-pt
and *-locale-de
, since some software
packages only provide locale files by language and not by
country-specific language).
The name of the output image files minus the extension.
This variable is derived using the
IMAGE_BASENAME
,
MACHINE
,
and
DATETIME
variables:
IMAGE_NAME = "${IMAGE_BASENAME}-${MACHINE}-${DATETIME}"
Defines a multiplier that the build system applies to the initial image
size for cases when the multiplier times the returned disk usage value
for the image is greater than the sum of
IMAGE_ROOTFS_SIZE
and
IMAGE_ROOTFS_EXTRA_SPACE
.
The result of the multiplier applied to the initial image size creates
free disk space in the image as overhead.
By default, the build process uses a multiplier of 1.3 for this variable.
This default value results in 30% free disk space added to the image when this
method is used to determine the final generated image size.
You should be aware that post install scripts and the package management
system uses disk space inside this overhead area.
Consequently, the multiplier does not produce an image with
all the theoretical free disk space.
See IMAGE_ROOTFS_SIZE
for information on how the build system determines the overall image size.
The default 30% free disk space typically gives the image enough room to boot and allows for basic post installs while still leaving a small amount of free disk space. If 30% free space is inadequate, you can increase the default value. For example, the following setting gives you 50% free space added to the image:
IMAGE_OVERHEAD_FACTOR = "1.5"
Alternatively, you can ensure a specific amount of free disk space is added
to the image by using the
IMAGE_ROOTFS_EXTRA_SPACE
variable.
Defines the package type (DEB, RPM, IPK, or TAR) used
by the OpenEmbedded build system.
The variable is defined appropriately by the
package_deb
,
package_rpm
,
package_ipk
,
or
package_tar
class.
The
package_sdk_base
and
image
classes use the IMAGE_PKGTYPE
for
packaging up images and SDKs.
You should not set the IMAGE_PKGTYPE
manually.
Rather, the variable is set indirectly through the
appropriate
package_*
class using the
PACKAGE_CLASSES
variable.
The OpenEmbedded build system uses the first package type
(e.g. DEB, RPM, or IPK) that appears with the variable
.tar
format are
never used as a substitute packaging format for DEB,
RPM, and IPK formatted files for your image or SDK.
Added by classes to run post processing commands once the OpenEmbedded build system has created the image. You can specify shell commands separated by semicolons:
IMAGE_POSTPROCESS_COMMAND += "<shell_command>; ... "
If you need to pass the path to the root filesystem within
the command, you can use
${IMAGE_ROOTFS}
, which points to
the root filesystem image.
The location of the root filesystem while it is under
construction (i.e. during do_rootfs
).
This variable is not configurable.
Do not change it.
Defines additional free disk space created in the image in Kbytes.
By default, this variable is set to "0".
This free disk space is added to the image after the build system determines
the image size as described in
IMAGE_ROOTFS_SIZE
.
This variable is particularly useful when you want to ensure that a specific amount of free disk space is available on a device after an image is installed and running. For example, to be sure 5 Gbytes of free disk space is available, set the variable as follows:
IMAGE_ROOTFS_EXTRA_SPACE = "5242880"
For example, the Yocto Project Build Appliance specifically requests 40 Gbytes of extra space with the line:
IMAGE_ROOTFS_EXTRA_SPACE = "41943040"
Defines the size in Kbytes for the generated image. The OpenEmbedded build system determines the final size for the generated image using an algorithm that takes into account the initial disk space used for the generated image, a requested size for the image, and requested additional free disk space to be added to the image. Programatically, the build system determines the final size of the generated image as follows:
if (image-du * overhead) < rootfs-size: internal-rootfs-size = rootfs-size + xspace else: internal-rootfs-size = (image-du * overhead) + xspace where: image-du = Returned value of the du command on the image. overhead = IMAGE_OVERHEAD_FACTOR rootfs-size = IMAGE_ROOTFS_SIZE internal-rootfs-size = Initial root filesystem size before any modifications. xspace = IMAGE_ROOTFS_EXTRA_SPACE
See the IMAGE_OVERHEAD_FACTOR
and IMAGE_ROOTFS_EXTRA_SPACE
variables for related information.
Specifies the complete list of supported image types by default:
jffs2 sum.jffs2 cramfs ext2 ext2.gz ext2.bz2 ext3 ext3.gz ext2.lzma btrfs live squashfs squashfs-xz ubi ubifs tar tar.gz tar.bz2 tar.xz cpio cpio.gz cpio.xz cpio.lzma vmdk elf
For more information on how these types of images, see
meta/classes/image_types*.bbclass
in the
Source Directory.
Helps define the recipe revision for recipes that share
a common include
file.
You can think of this variable as part of the recipe revision
as set from within an include file.
Suppose, for example, you have a set of recipes that
are used across several projects.
And, within each of those recipes the revision
(its PR
value) is set accordingly.
In this case, when the revision of those recipes changes,
the burden is on you to find all those recipes and
be sure that they get changed to reflect the updated
version of the recipe.
In this scenario, it can get complicated when recipes
that are used in many places and provide common functionality
are upgraded to a new revision.
A more efficient way of dealing with this situation is
to set the INC_PR
variable inside
the include
files that the recipes
share and then expand the INC_PR
variable within the recipes to help
define the recipe revision.
The following provides an example that shows how to use
the INC_PR
variable
given a common include
file that
defines the variable.
Once the variable is defined in the
include
file, you can use the
variable to set the PR
values in
each recipe.
You will notice that when you set a recipe's
PR
you can provide more granular
revisioning by appending values to the
INC_PR
variable:
recipes-graphics/xorg-font/xorg-font-common.inc:INC_PR = "r2" recipes-graphics/xorg-font/encodings_1.0.4.bb:PR = "${INC_PR}.1" recipes-graphics/xorg-font/font-util_1.3.0.bb:PR = "${INC_PR}.0" recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
The first line of the example establishes the baseline
revision to be used for all recipes that use the
include
file.
The remaining lines in the example are from individual
recipes and show how the PR
value
is set.
Specifies a space-separated list of license names
(as they would appear in
LICENSE
)
that should be excluded from the build.
Recipes that provide no alternatives to listed incompatible
licenses are not built.
Packages that are individually licensed with the specified
incompatible licenses will be deleted.
INCOMPATIBLE_LICENSE = "GPLv3"Although you can use other settings, you might be required to remove dependencies on or provide alternatives to components that are required to produce a functional system image.
Prevents the default dependencies, namely the C compiler
and standard C library (libc), from being added to
DEPENDS
.
This variable is usually used within recipes that do not
require any compilation using the C compiler.
Set the variable to "1" to prevent the default dependencies from being added.
If set to "1", causes the build to not strip binaries in resulting packages.
Causes the named class to be inherited at this point during parsing. The variable is only valid in configuration files.
Lists classes that will be inherited at the distribution level. It is unlikely that you want to edit this variable.
The default value of the variable is set as follows in the
meta/conf/distro/defaultsetup.conf
file:
INHERIT_DISTRO ?= "debian devshell sstate license"
Defines the format for the output image of an initial
RAM disk (initramfs), which is used during boot.
Supported formats are the same as those supported by the
IMAGE_FSTYPES
variable.
Indicates a filesystem image to use as an initial RAM
disk (initrd
).
The INITRD
variable is an optional
variable used with the
buildimg
class.
The filename of the initialization script as installed to
${sysconfdir}/init.d
.
This variable is used in recipes when using update-rc.d.bbclass
.
The variable is mandatory.
A list of the packages that contain initscripts.
If multiple packages are specified, you need to append the package name
to the other INITSCRIPT_*
as an override.
This variable is used in recipes when using update-rc.d.bbclass
.
The variable is optional and defaults to the
PN
variable.
Specifies the options to pass to update-rc.d
.
Here is an example:
INITSCRIPT_PARAMS = "start 99 5 2 . stop 20 0 1 6 ."
In this example, the script has a runlevel of 99, starts the script in initlevels 2 and 5, and stops the script in levels 0, 1 and 6.
The variable is mandatory and is used in recipes when using
update-rc.d.bbclass
.
Specifies the QA checks to skip for a specific package
within a recipe.
For example, to skip the check for symbolic link
.so
files in the main package of a
recipe, add the following to the recipe.
The package name override must be used, which in this
example is ${PN}
:
INSANE_SKIP_${PN} += "dev-so"
See the "insane.bbclass
"
section for a list of the valid QA checks you can
specify using this variable.
When the IPK backend is in use and package management
is enabled on the target, you can use this variable to
set up opkg
in the target image
to point to package feeds on a nominated server.
Once the feed is established, you can perform
installations or upgrades using the package manager
at runtime.
Defines the kernel architecture used when assembling the configuration. Architectures supported for this release are:
powerpc i386 x86_64 arm qemu mips
You define the KARCH
variable in the
BSP Descriptions.
A regular expression used by the build process to explicitly identify the kernel
branch that is validated, patched and configured during a build.
The KBRANCH
variable is optional.
You can use it to trigger checks to ensure the exact kernel branch you want is
being used by the build process.
Values for this variable are set in the kernel's recipe file and the kernel's
append file.
For example, if you are using the Yocto Project kernel that is based on the
Linux 3.4 kernel, the kernel recipe file is the
meta/recipes-kernel/linux/linux-yocto_3.4.bb
file.
Following is the default value for KBRANCH
and the default
override for the architectures the Yocto Project supports:
KBRANCH_DEFAULT = "standard/base" KBRANCH = "${KBRANCH_DEFAULT}"
This branch exists in the linux-yocto-3.4
kernel Git
repository http://git.yoctoproject.org/cgit.cgi/linux-yocto-3.4/refs/heads.
This variable is also used from the kernel's append file to identify the kernel
branch specific to a particular machine or target hardware.
The kernel's append file is located in the BSP layer for a given machine.
For example, the kernel append file for the Crown Bay BSP is in the
meta-intel
Git repository and is named
meta-crownbay/recipes-kernel/linux/linux-yocto_3.4.bbappend
.
Here are the related statements from the append file:
COMPATIBLE_MACHINE_crownbay = "crownbay" KMACHINE_crownbay = "crownbay" KBRANCH_crownbay = "standard/crownbay" COMPATIBLE_MACHINE_crownbay-noemgd = "crownbay-noemgd" KMACHINE_crownbay-noemgd = "crownbay" KBRANCH_crownbay-noemgd = "standard/crownbay"
The KBRANCH_*
statements identify the kernel branch to
use when building for the Crown Bay BSP.
In this case there are two identical statements: one for each type of
Crown Bay machine.
Defines the Linux kernel source repository's default
branch used to build the Linux kernel.
The KBRANCH_DEFAULT
value is
the default value for
KBRANCH
.
Unless you specify otherwise,
KBRANCH_DEFAULT
initializes to
"master".
Specifies additional make
command-line arguments the OpenEmbedded build system
passes on when compiling the kernel.
Includes additional metadata from the Yocto Project kernel Git repository.
In the OpenEmbedded build system, the default Board Support Packages (BSPs)
Metadata
is provided through
the KMACHINE
and KBRANCH
variables.
You can use the KERNEL_FEATURES
variable to further
add metadata for all BSPs.
The metadata you add through this variable includes config fragments and
features descriptions,
which usually includes patches as well as config fragments.
You typically override the KERNEL_FEATURES
variable
for a specific machine.
In this way, you can provide validated, but optional, sets of kernel
configurations and features.
For example, the following adds netfilter
to all
the Yocto Project kernels and adds sound support to the qemux86
machine:
# Add netfilter to all linux-yocto kernels KERNEL_FEATURES="features/netfilter" # Add sound support to the qemux86 machine KERNEL_FEATURES_append_qemux86=" cfg/sound"
The type of kernel to build for a device, usually set by the
machine configuration files and defaults to "zImage".
This variable is used
when building the kernel and is passed to make
as the target to
build.
The location of the kernel sources.
This variable is set to the value of the
STAGING_KERNEL_DIR
within the module.bbclass
class.
For information on how this variable is used, see the
"Incorporating Out-of-Tree Modules"
section.
The KERNEL_SRC
variable is identical to the KERNEL_PATH
variable.
The location of the kernel sources.
This variable is set to the value of the
STAGING_KERNEL_DIR
within the module.bbclass
class.
For information on how this variable is used, see the
"Incorporating Out-of-Tree Modules"
section.
The KERNEL_PATH
variable is identical to the KERNEL_SRC
variable.
Provides a short description of a configuration fragment.
You use this variable in the .scc
file that describes a configuration fragment file.
Here is the variable used in a file named
smp.scc
to describe SMP being
enabled:
define KFEATURE_DESCRIPTION "Enable SMP"
The machine as known by the kernel.
Sometimes the machine name used by the kernel does not match the machine name
used by the OpenEmbedded build system.
For example, the machine name that the OpenEmbedded build system understands as
qemuarm
goes by a different name in the Linux Yocto kernel.
The kernel understands that machine as arm_versatile926ejs
.
For cases like these, the KMACHINE
variable maps the
kernel machine name to the OpenEmbedded build system machine name.
Kernel machine names are initially defined in the
Yocto Linux Kernel's meta
branch.
From the meta
branch, look in
the meta/cfg/kernel-cache/bsp/<bsp_name>/<bsp-name>-<kernel-type>.scc
file.
For example, from the meta
branch in the
linux-yocto-3.0
kernel, the
meta/cfg/kernel-cache/bsp/cedartrail/cedartrail-standard.scc
file
has the following:
define KMACHINE cedartrail define KTYPE standard define KARCH i386 include ktypes/standard branch cedartrail include cedartrail.scc
You can see that the kernel understands the machine name for
the Cedar Trail Board Support Package (BSP) as
cedartrail
.
If you look in the Cedar Trail BSP layer in the
meta-intel
Source Repositories
at meta-cedartrail/recipes-kernel/linux/linux-yocto_3.0.bbappend
,
you will find the following statements among others:
COMPATIBLE_MACHINE_cedartrail = "cedartrail" KMACHINE_cedartrail = "cedartrail" KBRANCH_cedartrail = "yocto/standard/cedartrail" KERNEL_FEATURES_append_cedartrail += "bsp/cedartrail/cedartrail-pvr-merge.scc" KERNEL_FEATURES_append_cedartrail += "cfg/efi-ext.scc" COMPATIBLE_MACHINE_cedartrail-nopvr = "cedartrail" KMACHINE_cedartrail-nopvr = "cedartrail" KBRANCH_cedartrail-nopvr = "yocto/standard/cedartrail" KERNEL_FEATURES_append_cedartrail-nopvr += " cfg/smp.scc"
The KMACHINE
statements in the kernel's append file make sure that
the OpenEmbedded build system and the Yocto Linux kernel understand the same machine
names.
This append file uses two KMACHINE
statements.
The first is not really necessary but does ensure that the machine known to the
OpenEmbedded build system as cedartrail
maps to the machine
in the kernel also known as cedartrail
:
KMACHINE_cedartrail = "cedartrail"
The second statement is a good example of why the KMACHINE
variable
is needed.
In this example, the OpenEmbedded build system uses the cedartrail-nopvr
machine name to refer to the Cedar Trail BSP that does not support the proprietary
PowerVR driver.
The kernel, however, uses the machine name cedartrail
.
Thus, the append file must map the cedartrail-nopvr
machine name to
the kernel's cedartrail
name:
KMACHINE_cedartrail-nopvr = "cedartrail"
BSPs that ship with the Yocto Project release provide all mappings between the Yocto
Project kernel machine names and the OpenEmbedded machine names.
Be sure to use the KMACHINE
if you create a BSP and the machine
name you use is different than that used in the kernel.
Defines the kernel type to be used in assembling the configuration. The linux-yocto recipes define "standard", "tiny", and "preempt-rt" kernel types. See the "Kernel Types" section in the Yocto Project Linux Kernel Development Manual for more information on kernel types.
You define the KTYPE
variable in the
BSP Descriptions.
The value you use must match the value used for the
LINUX_KERNEL_TYPE
value used by the kernel recipe.
Provides a list of targets for automatic configuration.
See the
grub-efi
class for more information on how this variable is used.
Lists the layers that this recipe depends upon, separated by spaces.
Optionally, you can specify a specific layer version for a dependency
by adding it to the end of the layer name with a colon, (e.g. "anotherlayer:3"
to be compared against
LAYERVERSION
_anotherlayer
in this case).
An error will be produced if any dependency is missing or
the version numbers do not match exactly (if specified).
This variable is used in the conf/layer.conf
file
and must be suffixed with the name of the specific layer (e.g.
LAYERDEPENDS_mylayer
).
When used inside the layer.conf
configuration
file, this variable provides the path of the current layer.
This variable is not available outside of layer.conf
and references are expanded immediately when parsing of the file completes.
Optionally specifies the version of a layer as a single number.
You can use this within
LAYERDEPENDS
for another layer in order to depend on a specific version
of the layer.
This variable is used in the conf/layer.conf
file
and must be suffixed with the name of the specific layer (e.g.
LAYERVERSION_mylayer
).
Specifies the lead (or primary) compiled library file
(.so
) that the
debian
class applies its naming policy to given a recipe that
packages multiple libraries.
This variable works in conjunction with the
debian
class.
Checksums of the license text in the recipe source code.
This variable tracks changes in license text of the source code files. If the license text is changed, it will trigger a build failure, which gives the developer an opportunity to review any license change.
This variable must be defined for all recipes (unless
LICENSE
is set to "CLOSED")
For more information, see the Tracking License Changes section
The list of source licenses for the recipe. Follow these rules:
Do not use spaces within individual license names.
Separate license names using | (pipe) when there is a choice between licenses.
Separate license names using & (ampersand) when multiple licenses exist that cover different parts of the source.
You can use spaces between license names.
Here are some examples:
LICENSE = "LGPLv2.1 | GPLv3" LICENSE = "MPL-1 & LGPLv2.1" LICENSE = "GPLv2+"
The first example is from the recipes for Qt, which the user
may choose to distribute under either the LGPL version
2.1 or GPL version 3.
The second example is from Cairo where two licenses cover
different parts of the source code.
The final example is from sysstat
,
which presents a single license.
You can also specify licenses on a per-package basis to handle situations where components of the output have different licenses. For example, a piece of software whose code is licensed under GPLv2 but has accompanying documentation licensed under the GNU Free Documentation License 1.2 could be specified as follows:
LICENSE = "GFDL-1.2 & GPLv2" LICENSE_${PN} = "GPLv2" LICENSE_${PN}-doc = "GFDL-1.2"
Path to additional licenses used during the build.
By default, the OpenEmbedded build system uses COMMON_LICENSE_DIR
to define the directory that holds common license text used during the build.
The LICENSE_PATH
variable allows you to extend that
location to other areas that have additional licenses:
LICENSE_PATH += "/path/to/additional/common/licenses"
Defines the kernel type to be used in assembling the configuration. The linux-yocto recipes define "standard", "tiny", and "preempt-rt" kernel types. See the "Kernel Types" section in the Yocto Project Linux Kernel Development Manual for more information on kernel types.
If you do not specify a
LINUX_KERNEL_TYPE
, it defaults to
"standard".
Together with
KMACHINE
,
the LINUX_KERNEL_TYPE
variable
defines the search
arguments used by the kernel tools to find the appropriate
description within the kernel
Metadata
with which to build out the sources and configuration.
The Linux version from kernel.org
on which the Linux kernel image being built using the
OpenEmbedded build system is based.
You define this variable in the kernel recipe.
For example, the linux-yocto-3.4.bb
kernel recipe found in
meta/recipes-kernel/linux
defines the variables as follows:
LINUX_VERSION ?= "3.4.24"
The LINUX_VERSION
variable is used to
define PV
for the recipe:
PV = "${LINUX_VERSION}+git${SRCPV}"
A string extension compiled into the version string of the Linux kernel built with the OpenEmbedded build system. You define this variable in the kernel recipe. For example, the linux-yocto kernel recipes all define the variable as follows:
LINUX_VERSION_EXTENSION ?= "-yocto-${LINUX_KERNEL_TYPE}"
Defining this variable essentially sets the
Linux kernel configuration item
CONFIG_LOCALVERSION
, which is visible
through the uname
command.
Here is an example that shows the extension assuming it
was set as previously shown:
$ uname -r 3.7.0-rc8-custom
Specifies the directory to which the OpenEmbedded build
system writes overall log files.
The default directory is ${TMPDIR}/log
.
For the directory containing logs specific to each task,
see the T
variable.
Specifies the target device for which the image is built.
You define MACHINE
in the
local.conf
file found in the
Build Directory.
By default, MACHINE
is set to
"qemux86", which is an x86-based architecture machine to
be emulated using QEMU:
MACHINE ?= "qemux86"
The variable corresponds to a machine configuration file of the
same name, through which machine-specific configurations are set.
Thus, when MACHINE
is set to "qemux86" there
exists the corresponding qemux86.conf
machine
configuration file, which can be found in the
Source Directory
in meta/conf/machine
.
The list of machines supported by the Yocto Project as shipped include the following:
MACHINE ?= "qemuarm" MACHINE ?= "qemumips" MACHINE ?= "qemuppc" MACHINE ?= "qemux86" MACHINE ?= "qemux86-64" MACHINE ?= "genericx86" MACHINE ?= "genericx86-64" MACHINE ?= "beagleboard" MACHINE ?= "mpc8315e-rdb" MACHINE ?= "routerstationpro"
The last five are Yocto Project reference hardware boards, which
are provided in the meta-yocto-bsp
layer.
MACHINE
.
A list of required machine-specific packages to install as part of
the image being built.
The build process depends on these packages being present.
Furthermore, because this is a "machine essential" variable, the list of
packages are essential for the machine to boot.
The impact of this variable affects images based on
packagegroup-core-boot
,
including the core-image-minimal
image.
This variable is similar to the
MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS
variable with the exception that the image being built has a build
dependency on the variable's list of packages.
In other words, the image will not build if a file in this list is not found.
As an example, suppose the machine for which you are building requires
example-init
to be run during boot to initialize the hardware.
In this case, you would use the following in the machine's
.conf
configuration file:
MACHINE_ESSENTIAL_EXTRA_RDEPENDS += "example-init"
A list of recommended machine-specific packages to install as part of
the image being built.
The build process does not depend on these packages being present.
However, because this is a "machine essential" variable, the list of
packages are essential for the machine to boot.
The impact of this variable affects images based on
packagegroup-core-boot
,
including the core-image-minimal
image.
This variable is similar to the
MACHINE_ESSENTIAL_EXTRA_RDEPENDS
variable with the exception that the image being built does not have a build
dependency on the variable's list of packages.
In other words, the image will still build if a package in this list is not found.
Typically, this variable is used to handle essential kernel modules, whose
functionality may be selected to be built into the kernel rather than as a module,
in which case a package will not be produced.
Consider an example where you have a custom kernel where a specific touchscreen
driver is required for the machine to be usable.
However, the driver can be built as a module or
into the kernel depending on the kernel configuration.
If the driver is built as a module, you want it to be installed.
But, when the driver is built into the kernel, you still want the
build to succeed.
This variable sets up a "recommends" relationship so that in the latter case,
the build will not fail due to the missing package.
To accomplish this, assuming the package for the module was called
kernel-module-ab123
, you would use the
following in the machine's .conf
configuration
file:
MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "kernel-module-ab123"
Some examples of these machine essentials are flash, screen, keyboard, mouse, or touchscreen drivers (depending on the machine).
A list of machine-specific packages to install as part of the image being built that are not essential for the machine to boot. However, the build process for more fully-featured images depends on the packages being present.
This variable affects all images based on
packagegroup-base
, which does not include the
core-image-minimal
or core-image-basic
images.
The variable is similar to the
MACHINE_EXTRA_RRECOMMENDS
variable with the exception that the image being built has a build
dependency on the variable's list of packages.
In other words, the image will not build if a file in this list is not found.
An example is a machine that has WiFi capability but is not
essential for the machine to boot the image.
However, if you are building a more fully-featured image, you want to enable
the WiFi.
The package containing the firmware for the WiFi hardware is always
expected to exist, so it is acceptable for the build process to depend upon
finding the package.
In this case, assuming the package for the firmware was called
wifidriver-firmware
, you would use the following in the
.conf
file for the machine:
MACHINE_EXTRA_RDEPENDS += "wifidriver-firmware"
A list of machine-specific packages to install as part of the image being built that are not essential for booting the machine. The image being built has no build dependency on this list of packages.
This variable affects only images based on
packagegroup-base
, which does not include the
core-image-minimal
or core-image-basic
images.
This variable is similar to the
MACHINE_EXTRA_RDEPENDS
variable with the exception that the image being built does not have a build
dependency on the variable's list of packages.
In other words, the image will build if a file in this list is not found.
An example is a machine that has WiFi capability but is not essential
For the machine to boot the image.
However, if you are building a more fully-featured image, you want to enable
WiFi.
In this case, the package containing the WiFi kernel module will not be produced
if the WiFi driver is built into the kernel, in which case you still want the
build to succeed instead of failing as a result of the package not being found.
To accomplish this, assuming the package for the module was called
kernel-module-examplewifi
, you would use the
following in the .conf
file for the machine:
MACHINE_EXTRA_RRECOMMENDS += "kernel-module-examplewifi"
Specifies the list of hardware features the
MACHINE
is capable
of supporting.
For related information on enabling features, see the
DISTRO_FEATURES
,
COMBINED_FEATURES
,
and
IMAGE_FEATURES
variables.
For a list of hardware features supported by the Yocto Project as shipped, see the "Machine Features" section.
Features to be added to
MACHINE_FEATURES
if not also present in
MACHINE_FEATURES_BACKFILL_CONSIDERED
.
This variable is set in the meta/conf/bitbake.conf
file.
It is not intended to be user-configurable.
It is best to just reference the variable to see which machine features are
being backfilled for all machine configurations.
See the "Feature backfilling" section for
more information.
Features from
MACHINE_FEATURES_BACKFILL
that should not be backfilled (i.e. added to
MACHINE_FEATURES
)
during the build.
See the "Feature backfilling" section for
more information.
Lists overrides specific to the current machine.
By default, this list includes the value
of MACHINE
.
You can extend the list to apply variable overrides for
classes of machines.
For example, all QEMU emulated machines (e.g. qemuarm,
qemux86, and so forth) include a common file named
meta/conf/machine/include/qemu.inc
that prepends MACHINEOVERRIDES
with
the following variable override:
MACHINEOVERRIDES =. "qemuall:"
Applying an override like qemuall
affects all QEMU emulated machines elsewhere.
Here is an example from the
connman-conf
recipe:
SRC_URI_append_qemuall = "file://wired.config \ file://wired-setup \ "
The email address of the distribution maintainer.
Specifies additional paths from which the OpenEmbedded
build system gets source code.
When the build system searches for source code, it first
tries the local download directory.
If that location fails, the build system tries locations
defined by
PREMIRRORS
,
the upstream source, and then locations specified by
MIRRORS
in that order.
Assuming your distribution
(DISTRO
)
is "poky", the default value for
MIRRORS
is defined in the
conf/distro/poky.conf
file in the
meta-yocto
Git repository.
Specifies a prefix has been added to
PN
to create a special version
of a recipe or package, such as a Multilib version.
The variable is used in places where the prefix needs to be
added to or removed from a the name (e.g. the
BPN
variable).
MLPREFIX
gets set when a prefix has been
added to PN
.
Controls creation of the modules-*.tgz
file.
Set this variable to "0" to disable creation of this
file, which contains all of the kernel modules resulting
from a kernel build.
Separates files for different machines such that you can build
for multiple target machines using the same output directories.
See the STAMP
variable
for an example.
A string identifying the host distribution.
Strings consist of the host distributor ID
followed by the release, as reported by the
lsb_release
tool
or as read from /etc/lsb-release
.
For example, when running a build on Ubuntu 12.10, the value
is "Ubuntu-12.10".
If this information is unable to be determined, the value
resolves to "Unknown".
This variable is used by default to isolate native shared
state packages for different distributions (e.g. to avoid
problems with glibc
version
incompatibilities).
Additionally, the variable is checked against
SANITY_TESTED_DISTROS
if that variable is set.
Prevents installation of all "recommended-only" packages.
Recommended-only packages are packages installed only
through the
RRECOMMENDS
variable).
Setting the NO_RECOMMENDATIONS
variable
to "1" turns this feature on:
NO_RECOMMENDATIONS = "1"
You can set this variable globally in your
local.conf
file or you can attach it to
a specific image recipe by using the recipe name override:
NO_RECOMMENDATIONS_pn-<target_image> = "<package_name>"
It is important to realize that if you choose to not install
packages using this variable and some other packages are
dependent on them (i.e. listed in a recipe's
RDEPENDS
variable), the OpenEmbedded build system ignores your
request and will install the packages to avoid dependency
errors.
IMAGE_INSTALL
variable.
Support for this variable exists only when using the IPK and RPM packaging backend. Support does not exist for DEB.
See the
BAD_RECOMMENDATIONS
and the
PACKAGE_EXCLUDE
variables for related information.
Causes the OpenEmbedded build system to skip building the
.hddimg
image.
The NOHDD
variable is used with the
buildimg
class.
Set the variable to "1" to prevent the
.hddimg
image from being built.
Causes the OpenEmbedded build system to skip building the
ISO image.
The NOISO
variable is used with the
buildimg
class.
Set the variable to "1" to prevent the ISO image from
being built.
When a recipe inherits the
binconfig.bbclass
class, this variable
specifies additional arguments passed to the "sed" command.
The sed command alters any paths in configuration scripts
that have been set up during compilation.
Inheriting this class results in all paths in these scripts
being changed to point into the
sysroots/
directory so that all builds
that use the script will use the correct directories
for the cross compiling layout.
See the meta/classes/binconfig.bbclass
in the
Source Directory
for details on how this class applies these additional
sed command arguments.
For general information on the
binconfig.bbclass
class, see the
"Binary Configuration Scripts - binconfig.bbclass
"
section.
An internal variable used to tell the OpenEmbedded build system what Python modules to import for every Python function run by the system.
Controls how the OpenEmbedded build system spawns
interactive terminals on the host development system
(e.g. using the BitBake command with the
-c devshell
command-line option).
For more information, see the
"Using a Development Shell" section
in the Yocto Project Development Manual.
You can use the following values for the
OE_TERMINAL
variable:
auto gnome xfce rxvt screen konsole none
OE_TERMINAL
The directory from which the top-level build environment
setup script is sourced.
The Yocto Project makes two top-level build environment
setup scripts available:
oe-init-build-env
and
oe-init-build-env-memres
.
When you run one of these scripts, the
OEROOT
variable resolves to the
directory that holds the script.
For additional information on how this variable is used, see the initialization scripts.
Declares the oldest version of the Linux kernel that the
produced binaries must support.
This variable is passed into the build of the Embedded
GNU C Library (eglibc
).
The default for this variable comes from the
meta/conf/bitbake.conf
configuration
file.
You can override this default by setting the variable
in a custom distribution configuration file.
BitBake uses OVERRIDES
to control
what variables are overridden after BitBake parses
recipes and configuration files.
You can find more information on how overrides are handled
in the BitBake Manual that is located at
bitbake/doc/manual
in the
Source Directory.
The recipe name and version.
P
is comprised of the following:
${PN}-${PV}
The architecture of the resulting package or packages.
Enables easily adding packages to
PACKAGES
before ${PN}
so that those added packages can pick up files that would normally be
included in the default package.
This variable, which is set in the
local.conf
configuration file found in
the conf
folder of the
Build Directory,
specifies the package manager the OpenEmbedded build system
uses when packaging data.
You can provide one or more of the following arguments for the variable:
PACKAGE_CLASSES ?= "package_rpm package_deb package_ipk package_tar"
The build system uses only the first argument in the list
as the package manager when creating your image or SDK.
However, packages will be created using any additional
packaging classes you specify.
For example, if you use the following in your
local.conf
file:
PACKAGE_CLASSES ?= "package_ipk package_tar"
The OpenEmbedded build system uses the IPK package manager to create your image or SDK as well as generating TAR packages.
You cannot specify the
package_tar
class first in the list.
Files using the .tar
format cannot
be used as a substitute packaging format
for DEB, RPM, and IPK formatted files for your image or SDK.
For information on packaging and build performance effects
as a result of the package manager in use, see the
"package.bbclass
"
section.
Lists packages that should not be installed into an image. For example:
PACKAGE_EXCLUDE = "<package_name> <package_name> <package_name> ..."
You can set this variable globally in your
local.conf
file or you can attach it to
a specific image recipe by using the recipe name override:
PACKAGE_EXCLUDE_pn-<target_image> = "<package_name>"
If you choose to not install
a package using this variable and some other package is
dependent on it (i.e. listed in a recipe's
RDEPENDS
variable), the OpenEmbedded build system generates a fatal
installation error.
Because the build system halts the process with a fatal
error, you can use the variable with an iterative
development process to remove specific components from a
system.
Support for this variable exists only when using the IPK and RPM packaging backend. Support does not exist for DEB.
See the
NO_RECOMMENDATIONS
and the
BAD_RECOMMENDATIONS
variables for related information.
Specifies the list of architectures compatible with the device CPU. This variable is useful when you build for several different devices that use miscellaneous processors such as XScale and ARM926-EJS).
Defines one or more packages to include in an image when
a specific item is included in
IMAGE_FEATURES
.
When setting the value, PACKAGE_GROUP
should have the name of the feature item as an override.
Here is an example:
PACKAGE_GROUP_widget = "package1 package2"
In this example, if "widget" were added to
IMAGE_FEATURES
, "package1" and
"package2" would be included in the image.
PACKAGE_GROUP
are often package
groups.
While similarly named, you should not confuse the
PACKAGE_GROUP
variable with
package groups, which are discussed elsewhere in the
documentation.
The final list of packages passed to the package manager
for installation into the image.
Because the package manager controls actual installation
of all packages, the list of packages passed using
PACKAGE_INSTALL
is not the final list
of packages that are actually installed.
This variable is internal to the image construction
code.
Use the
IMAGE_INSTALL
variable to specify packages for installation.
This variable provides a means of enabling or disabling
features of a recipe on a per-recipe basis.
PACKAGECONFIG
blocks are defined
in recipes when you specify features and then arguments
that define feature behaviors.
Here is the basic block structure:
PACKAGECONFIG ??= "f1 f2 f3 ..." PACKAGECONFIG[f1] = "--with-f1,--without-f1,build-deps-f1,rt-deps-f1" PACKAGECONFIG[f2] = "--with-f2,--without-f2,build-deps-f2,rt-deps-f2" PACKAGECONFIG[f3] = "--with-f3,--without-f3,build-deps-f3,rt-deps-f3"
The PACKAGECONFIG
variable itself specifies a space-separated list of the
features to enable.
Following the features, you can determine the behavior of
each feature by providing up to four order-dependent
arguments, which are separated by commas.
You can omit any argument you like but must retain the
separating commas.
The order is important and specifies the following:
Extra arguments
that should be added to the configure script
argument list
(EXTRA_OECONF
)
if the feature is enabled.
Extra arguments
that should be added to EXTRA_OECONF
if the feature is disabled.
Additional build dependencies
(DEPENDS
)
that should be added if the feature is enabled.
Additional runtime dependencies
(RDEPENDS
)
that should be added if the feature is enabled.
Consider the following
PACKAGECONFIG
block taken from the
librsvg
recipe.
In this example the feature is croco
,
which has three arguments that determine the feature's
behavior.
PACKAGECONFIG ??= "croco" PACKAGECONFIG[croco] = "--with-croco,--without-croco,libcroco"
The --with-croco
and
libcroco
arguments apply only if
the feature is enabled.
In this case, --with-croco
is
added to the configure script argument list and
libcroco
is added to
DEPENDS
.
On the other hand, if the feature is disabled say through
a .bbappend
file in another layer, then
the second argument --without-croco
is
added to the configure script rather than
--with-croco
.
The basic PACKAGECONFIG
structure
previously described holds true regardless of whether you
are creating a block or changing a block.
When creating a block, use the structure inside your
recipe.
If you want to change an existing
PACKAGECONFIG
block, you can do so
one of two ways:
Append file:
Create an append file named
<recipename>.bbappend
in your
layer and override the value of
PACKAGECONFIG
.
You can either completely override the variable:
PACKAGECONFIG="f4 f5"
Or, you can just append the variable:
PACKAGECONFIG_append = " f4"
Configuration file:
This method is identical to changing the block
through an append file except you edit your
local.conf
or
<mydistro>.conf
file.
As with append files previously described,
you can either completely override the variable:
PACKAGECONFIG_pn-<recipename>="f4 f5"
Or, you can just amend the variable:
PACKAGECONFIG_append_pn-<recipename> = " f4"
The list of packages to be created from the recipe. The default value is the following:
${PN}-dbg ${PN}-staticdev ${PN}-dev ${PN}-doc ${PN}-locale ${PACKAGE_BEFORE_PN} ${PN}
A promise that your recipe satisfies runtime dependencies
for optional modules that are found in other recipes.
PACKAGES_DYNAMIC
does not actually satisfy the dependencies, it only states that
they should be satisfied.
For example, if a hard, runtime dependency
(RDEPENDS
)
of another package is satisfied
at build time through the PACKAGES_DYNAMIC
variable, but a package with the module name is never actually
produced, then the other package will be broken.
Thus, if you attempt to include that package in an image,
you will get a dependency failure from the packaging system
during do_rootfs
.
Typically, if there is a chance that such a situation can
occur and the package that is not created is valid
without the dependency being satisfied, then you should use
RRECOMMENDS
(a soft runtime dependency) instead of
RDEPENDS
.
For an example of how to use the PACKAGES_DYNAMIC
variable when you are splitting packages, see the
"Handling Optional Module Packaging" section
in the Yocto Project Development Manual.
Extra options that are passed to the
make
command during the
do_compile
task in order to specify
parallel compilation.
This variable is usually in the form
-j 4
, where the number
represents the maximum number of parallel threads make can
run.
If you development host supports multiple cores a good
rule of thumb is to set this variable to twice the number
of cores on the host.
make
process in parallel.
Extra options passed to the
make install
command during the
do_install
task in order to specify
parallel installation.
This variable defaults to the value of
PARALLEL_MAKE
.
make install
process in parallel.
Determines the action to take when a patch fails. You can set this variable to one of two values: "noop" and "user".
The default value of "noop" causes the build to simply fail when the OpenEmbedded build system cannot successfully apply a patch. Setting the value to "user" causes the build system to launch a shell and places you in the right location so that you can manually resolve the conflicts.
Set this variable in your
local.conf
file.
Specifies the utility used to apply patches for a recipe
during do_patch
.
You can specify one of three utilities: "patch", "quilt", or
"git".
The default utility used is "quilt" except for the
quilt-native recipe itself.
Because the quilt tool is not available at the
time quilt-native is being patched, it uses "patch".
If you wish to use an alternative patching tool, set the variable in the recipe using one of the following:
PATCHTOOL = "patch" PATCHTOOL = "quilt" PATCHTOOL = "git"
the epoch of the recipe. By default, this variable is unset. The field is used to make upgrades possible when the versioning scheme changes in some backwards incompatible way.
Specifies the recipe or package name and includes all version and revision
numbers (i.e. eglibc-2.13-r20+svnr15508/
and
bash-4.2-r1/
).
This variable is comprised of the following:
${PN}-${EXTENDPE}${PV}-${PR}
When a recipe inherits the
pixbufcache
class, this variable identifies packages that contain
the pixbuf loaders used with
gdk-pixbuf
.
By default, the pixbufcache
class
assumes that the loaders are in the recipe's main package
(i.e. ${
PN
}
).
Use this variable if the loaders you need are in a package
other than that main package.
Points to the destination directory for files to be packaged before they are split into individual packages. This directory defaults to the following:
${WORKDIR}/package
Do not change this default.
Points to a shared, global-state directory that holds data
generated during the packaging process.
During the packaging process, the
do_packagedata
task packages
data for each recipe and installs it into this temporary,
shared area.
This directory defaults to the following:
${STAGING_DIR_HOST}/pkgdata
Do not change this default.
Points to the parent directory for files to be packaged after they have been split into individual packages. This directory defaults to the following:
${WORKDIR}/packages-split
Under this directory, the build system creates
directories for each package specified in
PACKAGES
.
Do not change this default.
Points to a temporary work area used by the
do_package
task to write output
from the do_packagedata
task.
The PKGDESTWORK
location defaults to
the following:
${WORKDIR}/pkgdata
The do_packagedata
task then packages
the data in the temporary work area and installs it into a
shared directory pointed to by
PKGDATA_DIR
.
Do not change this default.
This variable can have two separate functions depending on the context: a recipe name or a resulting package name.
PN
refers to a recipe name in the context of a file used
by the OpenEmbedded build system as input to create a package.
The name is normally extracted from the recipe file name.
For example, if the recipe is named
expat_2.0.1.bb
, then the default value of PN
will be "expat".
The variable refers to a package name in the context of a file created or produced by the OpenEmbedded build system.
If applicable, the PN
variable also contains any special
suffix or prefix.
For example, using bash
to build packages for the native
machine, PN
is bash-native
.
Using bash
to build packages for the target and for Multilib,
PN
would be bash
and
lib64-bash
, respectively.
Lists recipes you do not want the OpenEmbedded build system
to build.
This variable works in conjunction with the
blacklist
class, which the recipe must inherit globally.
To prevent a recipe from being built, inherit the class
globally and use the variable in your
local.conf
file.
Here is an example that prevents
myrecipe
from being built:
INHERIT += "blacklist" PNBLACKLIST[myrecipe] = "Not supported by our organization."
The revision of the recipe. The default value for this variable is "r0".
If multiple recipes provide an item, this variable
determines which recipe should be given preference.
You should always suffix the variable with the name of the
provided item, and you should set it to the
PN
of the recipe to which you want to give precedence.
Some examples:
PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto" PREFERRED_PROVIDER_virtual/xserver = "xserver-xf86" PREFERRED_PROVIDER_virtual/libgl ?= "mesa"
If there are multiple versions of recipes available, this
variable determines which recipe should be given preference.
You must always suffix the variable with the
PN
you want to select, and you should set the
PV
accordingly for precedence.
You can use the "%
" character as a
wildcard to match any number of characters, which can be
useful when specifying versions that contain long revision
numbers that could potentially change.
Here are two examples:
PREFERRED_VERSION_python = "2.7.3" PREFERRED_VERSION_linux-yocto = "3.10%"
Specifies additional paths from which the OpenEmbedded
build system gets source code.
When the build system searches for source code, it first
tries the local download directory.
If that location fails, the build system tries locations
defined by PREMIRRORS
, the upstream
source, and then locations specified by
MIRRORS
in that order.
Assuming your distribution
(DISTRO
)
is "poky", the default value for
PREMIRRORS
is defined in the
conf/distro/poky.conf
file in the
meta-yocto
Git repository.
Typically, you could add a specific server for the
build system to attempt before any others by adding
something like the following to the
local.conf
configuration file in the
Build Directory:
PREMIRRORS_prepend = "\ git://.*/.* http://www.yoctoproject.org/sources/ \n \ ftp://.*/.* http://www.yoctoproject.org/sources/ \n \ http://.*/.* http://www.yoctoproject.org/sources/ \n \ https://.*/.* http://www.yoctoproject.org/sources/ \n"
These changes cause the build system to intercept
Git, FTP, HTTP, and HTTPS requests and direct them to
the http://
sources mirror.
You can use file://
URLs to point
to local directories or network shares as well.
Causes the PR
variable of .bbappend
files to
dynamically increment.
This increment minimizes the impact of layer ordering.
In order to ensure multiple .bbappend
files can co-exist,
PRINC
should be self-referencing.
This variable defaults to 0.
Following is an example that increments PR
by two:
PRINC := "${@int(PRINC) + 2}"
It is advisable not to use strings such as ".= '.1'" with the variable because
this usage is very sensitive to layer ordering.
You should avoid explicit assignments as they cannot
adequately represent multiple
.bbappend
files.
A list of aliases that a recipe also provides.
These aliases are useful for satisfying dependencies of
other recipes during the build (as specified by
DEPENDS
).
The network based
PR
service host and port.
The conf/local.conf.sample.extended
configuration file in the
Source Directory
shows how the PRSERV_HOST
variable is
set:
PRSERV_HOST = "localhost:0"
You must set the variable if you want to automatically
start a local
PR service.
You can set PRSERV_HOST
to other
values to use a remote PR service.
The version of the recipe.
The version is normally extracted from the recipe filename.
For example, if the recipe is named
expat_2.0.1.bb
, then the default value of PV
will be "2.0.1".
PV
is generally not overridden within
a recipe unless it is building an unstable (i.e. development) version from a source code repository
(e.g. Git or Subversion).
Specifies your own subset of .pro
files to be built for use with
qmake
.
If you do not set this variable, all
.pro
files in the directory pointed to
by S
will be built by default.
This variable is used with recipes that inherit the
qmake_base
class or other classes that inherit
qmake_base
.
The list of packages that conflict with packages. Note that packages will not be installed if conflicting packages are not first removed.
Like all package-controlling variables, you must always use them in conjunction with a package name override. Here is an example:
RCONFLICTS_${PN} = "another-conflicting-package-name"
BitBake, which the OpenEmbedded build system uses, supports
specifying versioned dependencies.
Although the syntax varies depending on the packaging
format, BitBake hides these differences from you.
Here is the general syntax to specify versions with
the RCONFLICTS
variable:
RCONFLICTS_${PN} = "<package> (<operator> <version>)"
For operator
, you can specify the
following:
= < > <= >=
For example, the following sets up a dependency on version
1.2 or greater of the package foo
:
RCONFLICTS_${PN} = "foo (>= 1.2)"
Lists a package's runtime dependencies (i.e. other packages) that must be installed in order for the built package to run correctly. If a package in this list cannot be found during the build, you will get a build error.
When you use the RDEPENDS
variable
in a recipe, you are essentially stating that the recipe's
do_build
task depends on the existence
of a specific package.
Consider this simple example for two recipes named "a" and
"b" that produce similarly named packages.
In this example, the RDEPENDS
statement appears in the "a" recipe:
RDEPENDS_${PN} = "b"
Here, the dependency is such that the
do_build
task for recipe "a" depends
on the do_package_write
task
of recipe "b".
This means the package file for "b" must be available when
the output for recipe "a" has been completely built.
More importantly, package "a" will be marked as depending
on package "b" in a manner that is understood by the
package manager in use (i.e. rpm, opkg, or dpkg).
The names of the packages you list within
RDEPENDS
must be the names of other
packages - they cannot be recipe names.
Although package names and recipe names usually match,
the important point here is that you are
providing package names within the
RDEPENDS
variable.
For an example of the default list of packages created from
a recipe, see the
PACKAGES
variable.
Because the RDEPENDS
variable applies
to packages being built, you should always use the variable
in a form with an attached package name.
For example, suppose you are building a development package
that depends on the perl
package.
In this case, you would use the following
RDEPENDS
statement:
RDEPENDS_${PN}-dev += "perl"
In the example, the development package depends on
the perl
package.
Thus, the RDEPENDS
variable has the
${PN}-dev
package name as part of the
variable.
The package name you attach to the
RDEPENDS
variable must appear
as it would in the PACKAGES
namespace before any renaming of the output package by
classes like debian.bbclass
.
In many cases you do not need to explicitly add
runtime dependencies using
RDEPENDS
since some automatic
handling occurs:
shlibdeps
: If
a runtime package contains a shared library
(.so
), the build
processes the library in order to determine other
libraries to which it is dynamically linked.
The build process adds these libraries to
RDEPENDS
when creating the runtime
package.
pcdeps
: If
the package ships a pkg-config
information file, the build process uses this file
to add items to the RDEPENDS
variable to create the runtime packages.
BitBake, which the OpenEmbedded build system uses, supports
specifying versioned dependencies.
Although the syntax varies depending on the packaging
format, BitBake hides these differences from you.
Here is the general syntax to specify versions with
the RDEPENDS
variable:
RDEPENDS_${PN} = "<package> (<operator> <version>)"
For operator
, you can specify the
following:
= < > <= >=
For example, the following sets up a dependency on version
1.2 or greater of the package foo
:
RDEPENDS_${PN} = "foo (>= 1.2)"
For information on build-time dependencies, see the
DEPENDS
variable.
When a recipe inherits the
distro_features_check
class, this
variable identifies distribution features that must
exist in the current configuration in order for the
OpenEmbedded build system to build the recipe.
In other words, if the
REQUIRED_DISTRO_FEATURES
variable
lists a feature that does not appear in
DISTRO_FEATURES
within the
current configuration, an error occurs and the
build stops.
Reclaims disk space by removing previously built
versions of the same image from the
images
directory pointed to by the
DEPLOY_DIR
variable.
Set this variable to "1" in your
local.conf
file to remove these
images.
With rm_work
enabled, this
variable specifies a list of recipes whose work directories
should not be removed.
See the "rm_work.bbclass
"
section for more details.
Indicates a filesystem image to include as the root filesystem.
The ROOTFS
variable is an optional
variable used with the
buildimg
class.
Added by classes to run post processing commands once the OpenEmbedded build system has created the root filesystem. You can specify shell commands separated by semicolons:
ROOTFS_POSTPROCESS_COMMAND += "<shell_command>; ... "
If you need to pass the path to the root filesystem within
the command, you can use
${IMAGE_ROOTFS}
, which points to
the root filesystem image.
A list of package name aliases that a package also provides.
These aliases are useful for satisfying runtime dependencies
of other packages both during the build and on the target
(as specified by
RDEPENDS
).
RPROVIDES
list.
As with all package-controlling variables, you must always use the variable in conjunction with a package name override. Here is an example:
RPROVIDES_${PN} = "widget-abi-2"
A list of packages that extends the usability of a package
being built.
The package being built does not depend on this list of
packages in order to successfully build, but needs them for
the extended usability.
To specify runtime dependencies for packages, see the
RDEPENDS
variable.
The OpenEmbedded build process automatically installs the
list of packages as part of the built package.
However, you can remove these packages later if you want.
If, during the build, a package from the
RRECOMMENDS
list cannot be
found, the build process continues without an error.
You can also prevent packages in the list from being
installed by using several variables.
See the
BAD_RECOMMENDATIONS
,
NO_RECOMMENDATIONS
,
and
PACKAGE_EXCLUDE
variables for more information.
Because the RRECOMMENDS
variable
applies to packages being built, you should always attach
an override to the variable to specify the particular
package whose usability is being extended.
For example, suppose you are building a development package
that is extended to support wireless functionality.
In this case, you would use the following:
RRECOMMENDS_${PN}-dev += "<wireless_package_name>"
In the example, the package name
(${PN}-dev
)
must appear as it would in the
PACKAGES
namespace before any renaming of the output package by
classes such as debian.bbclass
.
BitBake, which the OpenEmbedded build system uses, supports
specifying versioned recommends.
Although the syntax varies depending on the packaging
format, BitBake hides these differences from you.
Here is the general syntax to specify versions with
the RRECOMMENDS
variable:
RRECOMMENDS_${PN} = "<package> (<operator> <version>)"
For operator
, you can specify the
following:
= < > <= >=
For example, the following sets up a recommend on version
1.2 or greater of the package foo
:
RRECOMMENDS_${PN} = "foo (>= 1.2)"
A list of packages replaced by a package.
The package manager uses this variable to determine which
package should be installed to replace other package(s)
during an upgrade.
In order to also have the other package(s) removed at the
same time, you must add the name of the other
package to the
RCONFLICTS
variable.
As with all package-controlling variables, you must use this variable in conjunction with a package name override. Here is an example:
RREPLACES_${PN} = "other-package-being-replaced"
BitBake, which the OpenEmbedded build system uses, supports
specifying versioned replacements.
Although the syntax varies depending on the packaging
format, BitBake hides these differences from you.
Here is the general syntax to specify versions with
the RREPLACES
variable:
RREPLACES_${PN} = "<package> (<operator> <version>)"
For operator
, you can specify the
following:
= < > <= >=
For example, the following sets up a replacement using
version 1.2 or greater of the package
foo
:
RREPLACES_${PN} = "foo (>= 1.2)"
A list of additional packages that you can suggest for installation by the package manager at the time a package is installed. Not all package managers support this functionality.
As with all package-controlling variables, you must always use this variable in conjunction with a package name override. Here is an example:
RSUGGESTS_${PN} = "useful-package another-package"
The location in the
Build Directory
where unpacked recipe source code resides.
This location is within the work directory
(WORKDIR
),
which is not static.
The unpacked source location depends on the recipe name
(PN
) and
recipe version
(PV
) as
follows:
${WORKDIR}/${PN}-${PV}
As an example, assume a
Source Directory
top-level folder named poky
and a
default Build Directory at poky/build
.
In this case, the work directory the build system uses
to keep the unpacked recipe for db
is the following:
poky/build/tmp/work/qemux86-poky-linux/db/5.1.19-r3/db-5.1.19
A list of the host distribution identifiers that the
build system has been tested against.
Identifiers consist of the host distributor ID
followed by the release,
as reported by the lsb_release
tool
or as read from /etc/lsb-release
.
Separate the list items with explicit newline
characters (\n
).
If SANITY_TESTED_DISTROS
is not empty
and the current value of
NATIVELSBSTRING
does not appear in the list, then the build system reports
a warning that indicates the current host distribution has
not been tested as a build host.
The target architecture for the SDK.
Typically, you do not directly set this variable.
Instead, use
SDKMACHINE
.
The directory set up and used by the
populate_sdk_base
to which the SDK is deployed.
The populate_sdk_base
class defines
SDK_DEPLOY
as follows:
SDK_DEPLOY = "${TMPDIR}/deploy/sdk"
The parent directory used by the OpenEmbedded build system
when creating SDK output.
The
populate_sdk_base
class defines the variable as follows:
SDK_DIR = "${WORKDIR
}/sdk"
SDK_DIR
directory is a
temporary directory as it is part of
WORKDIR
.
The final output directory is
SDK_DEPLOY
.
The base name for SDK output files.
The name is derived from the
DISTRO
,
TCLIBC
,
SDK_ARCH
,
IMAGE_BASENAME
,
and
TUNE_PKGARCH
variables:
SDK_NAME = "${DISTRO}-${TCLIBC}-${SDK_ARCH}-${IMAGE_BASENAME}-${TUNE_PKGARCH}"
The location used by the OpenEmbedded build system when
creating SDK output.
The
populate_sdk_base
class defines the variable as follows:
SDK_OUTPUT = "${SDK_DIR}/image"
SDK_OUTPUT
directory is a
temporary directory as it is part of
WORKDIR
by way of
SDK_DIR
.
The final output directory is
SDK_DEPLOY
.
Equivalent to
IMAGE_FEATURES
.
However, this variable applies to the SDK generated from an
image using the following command:
$ bitbake -c populate_sdk imagename
The architecture of the machine that runs Application Development Toolkit (ADT) items. In other words, packages are built so that they will run on the target you specify with the argument. This implies that you can build out ADT/SDK items that run on an architecture other than that of your build host. For example, you can use an x86_64-based build host to create packages that will run on an i686-based SDK Machine.
You can use "i686" and "x86_64" as possible values for this
variable.
The variable defaults to "i686" and is set in the
local.conf
file in the
Build Directory.
SDKMACHINE ?= "i686"
The section in which packages should be categorized. Package management utilities can make use of this variable.
The variable takes the value of
FULL_OPTIMIZATION
unless DEBUG_BUILD
= "1".
In this case the value of
DEBUG_OPTIMIZATION
is used.
Defines a serial console (TTY) to enable using getty. Provide a value that specifies the baud rate followed by the TTY device name separated by a space. You cannot specify more than one TTY device:
SERIAL_CONSOLE = "115200 ttyS0"
Defines the serial consoles (TTYs) to enable using getty. Provide a value that specifies the baud rate followed by the TTY device name separated by a semicolon. Use spaces to separate multiple devices:
SERIAL_CONSOLES = "115200;ttyS0 115200;ttyS1"
Similar to
SERIAL_CONSOLES
except the device is checked for existence before attempting
to enable it.
This variable is currently only supported with SysVinit
(i.e. not with systemd).
A list of recipe dependencies that should not be used to determine signatures of tasks from one recipe when they depend on tasks from another recipe. For example:
SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS += "intone->mplayer2"
In this example, intone
depends on
mplayer2
.
Use of this variable is one mechanism to remove dependencies that affect task signatures and thus force rebuilds when a recipe changes.
A list of recipes that are completely stable and will never change. The ABI for the recipes in the list are presented by output from the tasks run to build the recipe. Use of this variable is one way to remove dependencies from one recipe on another that affect task signatures and thus force rebuilds when the recipe changes.
Specifies the number of bits for the target system CPU. The value should be either "32" or "64".
Specifies the endian byte order of the target system. The value should be either "le" for little-endian or "be" for big-endian.
Groups together machines based upon the same family
of SOC (System On Chip).
You typically set this variable in a common
.inc
file that you include in the
configuration files of all the machines.
conf/machine/include/soc-family.inc
for this variable to appear in
MACHINEOVERRIDES
.
Defines the suffix for shared libraries used on the
target platform.
By default, this suffix is ".so.*" for all Linux-based
systems and is defined in the
meta/conf/bitbake.conf
configuration
file.
You will see this variable referenced in the default values
of FILES_${PN}
.
Defines the suffix for the development symbolic link
(symlink) for shared libraries on the target platform.
By default, this suffix is ".so" for Linux-based
systems and is defined in the
meta/conf/bitbake.conf
configuration
file.
You will see this variable referenced in the default values
of FILES_${PN}-dev
.
Defines your own
PREMIRRORS
from which to first fetch source before attempting to fetch
from the upstream specified in
SRC_URI
.
To use this variable, you must globally inherit the
own-mirrors
class and then provide the URL to your mirrors.
Here is an example:
INHERIT += "own-mirrors" SOURCE_MIRROR_URL = "http://example.com/my-source-mirror"
SOURCE_MIRROR_URL
.
A list of prefixes for PN
used by the
OpenEmbedded build system to create variants of recipes or packages.
The list specifies the prefixes to strip off during certain circumstances
such as the generation of the BPN
variable.
The list of source files - local or remote.
This variable tells the OpenEmbedded build system which bits
to pull in for the build and how to pull them in.
For example, if the recipe or append file only needs to
fetch a tarball from the Internet, the recipe or
append file uses a single SRC_URI
entry.
On the other hand, if the recipe or append file needs to
fetch a tarball, apply two patches, and include a custom
file, the recipe or append file would include four
instances of the variable.
The following list explains the available URI protocols:
file://
-
Fetches files, which are usually files shipped with
the
Metadata,
from the local machine.
The path is relative to the
FILESPATH
variable.
Thus, the build system searches, in order, from the
following directories, which are assumed to be a
subdirectories of the directory in which the
recipe file (.bb
) or
append file (.bbappend
)
resides:
${BPN}
-
The base recipe name without any special
suffix or version numbers.
${BP}
-
${BPN}-${PV}
.
The base recipe name and version but without
any special package name suffix.
files -
Files within a directory, which is named
files
and is also
alongside the recipe or append file.
SRC_URI
statement from your append file, you need to be
sure to extend the
FILESPATH
variable by also using the
FILESEXTRAPATHS
variable from within your append file.
bzr://
- Fetches files from a
Bazaar revision control repository.
git://
- Fetches files from a
Git revision control repository.
osc://
- Fetches files from
an OSC (OpenSUSE Build service) revision control repository.
repo://
- Fetches files from
a repo (Git) repository.
svk://
- Fetches files from
an SVK revision control repository.
http://
- Fetches files from
the Internet using http
.
https://
- Fetches files
from the Internet using https
.
ftp://
- Fetches files
from the Internet using ftp
.
cvs://
- Fetches files from
a CVS revision control repository.
hg://
- Fetches files from
a Mercurial (hg
) revision control repository.
p4://
- Fetches files from
a Perforce (p4
) revision control repository.
ssh://
- Fetches files from
a secure shell.
svn://
- Fetches files from
a Subversion (svn
) revision control repository.
Standard and recipe-specific options for SRC_URI
exist.
Here are standard options:
apply
- Whether to apply
the patch or not.
The default action is to apply the patch.
striplevel
- Which
striplevel to use when applying the patch.
The default level is 1.
patchdir
- Specifies
the directory in which the patch should be applied.
The default is ${
S
}
.
Here are options specific to recipes building code from a revision control system:
mindate
-
Apply the patch only if
SRCDATE
is equal to or greater than mindate
.
maxdate
-
Apply the patch only if SRCDATE
is not later than mindate
.
minrev
-
Apply the patch only if SRCREV
is equal to or greater than minrev
.
maxrev
-
Apply the patch only if SRCREV
is not later than maxrev
.
rev
-
Apply the patch only if SRCREV
is equal to rev
.
notrev
-
Apply the patch only if SRCREV
is not equal to rev
.
Here are some additional options worth mentioning:
unpack
- Controls
whether or not to unpack the file if it is an archive.
The default action is to unpack the file.
subdir
- Places the file
(or extracts its contents) into the specified
subdirectory of WORKDIR
.
This option is useful for unusual tarballs or other archives that
do not have their files already in a subdirectory within the archive.
name
- Specifies a
name to be used for association with SRC_URI
checksums
when you have more than one file specified in SRC_URI
.
downloadfilename
- Specifies
the filename used when storing the downloaded file.
By default, the OpenEmbedded build system automatically detects whether
SRC_URI
contains files that are machine-specific.
If so, the build system automatically changes
PACKAGE_ARCH
.
Setting this variable to "0" disables this behavior.
The date of the source code used to build the package. This variable applies only if the source was fetched from a Source Code Manager (SCM).
Returns the version string of the current package.
This string is used to help define the value of
PV
.
The SRCPV
variable is defined in the
meta/conf/bitbake.conf
configuration
file in the
Source Directory
as follows:
SRCPV = "${@bb.fetch2.get_srcrev(d)}"
Recipes that need to define PV
do so
with the help of the SRCPV
.
For example, the ofono
recipe
(ofono_git.bb
) located in
meta/recipes-connectivity
in the
Source Directory defines PV
as
follows:
PV = "0.12-git${SRCPV}"
The revision of the source code used to build the package.
This variable applies to Subversion, Git, Mercurial and Bazaar
only.
Note that if you wish to build a fixed revision and you wish
to avoid performing a query on the remote repository every time
BitBake parses your recipe, you should specify a SRCREV
that is a
full revision identifier and not just a tag.
The directory for the shared state cache.
Configures the OpenEmbedded build system to search other
mirror locations for prebuilt cache data objects before
building out the data.
This variable works like fetcher
MIRRORS
and PREMIRRORS
and points to the cache locations to check for the shared
objects.
You can specify a filesystem directory or a remote URL such as HTTP or FTP. The locations you specify need to contain the shared state cache (sstate-cache) results from previous builds. The sstate-cache you point to can also be from builds on other machines.
If a mirror uses the same structure as
SSTATE_DIR
,
you need to add
"PATH" at the end as shown in the examples below.
The build system substitutes the correct path within the
directory structure.
SSTATE_MIRRORS ?= "\ file://.* http://someserver.tld/share/sstate/PATH \n \ file://.* file:///some/local/dir/sstate/PATH"
The directory with kernel headers that are required to build out-of-tree modules.
Specifies the base path used to create recipe stamp files.
The path to an actual stamp file is constructed by evaluating this
string and then appending additional information.
Currently, the default assignment for STAMP
as set in the meta/conf/bitbake.conf
file
is:
STAMP = "${STAMPS_DIR}/${MULTIMACH_TARGET_SYS}/${PN}/${EXTENDPE}${PV}-${PR}"
See STAMPS_DIR
,
MULTIMACH_TARGET_SYS
,
PN
,
EXTENDPE
,
PV
, and
PR
for related variable
information.
Specifies the base directory in which the OpenEmbedded
build system places stamps.
The default directory is
${TMPDIR}/stamps
.
The short (72 characters or less) summary of the binary package for packaging
systems such as opkg
, rpm
or
dpkg
.
By default, SUMMARY
is used to define
the DESCRIPTION
variable if DESCRIPTION
is not set
in the recipe.
Specifies the kernel boot default console. If you want to use a console other than the default, set this variable in your recipe as follows where "X" is the console number you want to use:
SYSLINUX_DEFAULT_CONSOLE = "console=ttyX"
The
syslinux
class initially sets this variable to null but then checks
for a value later.
Lists additional options to add to the syslinux file.
You need to set this variable in your recipe.
If you want to list multiple options, separate the options
with a semicolon character (;
).
The
syslinux
class uses this variable to create a set of options.
Specifies the alternate serial port or turns it off.
To turn off serial, set this variable to an empty string
in your recipe.
The variable's default value is set in the
syslinux
as follows:
SYSLINUX_SERIAL ?= "0 115200"
The class checks for and uses the variable as needed.
An .LSS
file used as the background
for the VGA boot menu when you are using the boot menu.
You need to set this variable in your recipe.
The
syslinux
class checks for this variable and if found, the
OpenEmbedded build system installs the splash screen.
Specifies the alternate console=tty... kernel boot argument.
The variable's default value is set in the
syslinux
as follows:
SYSLINUX_SERIAL_TTY ?= "console=ttyS0,115200"
The class checks for and uses the variable as needed.
A list of functions to execute after files are staged into the sysroot. These functions are usually used to apply additional processing on the staged files, or to stage additional files.
For recipes that inherit the
systemd
class, this variable specifies whether the service you have
specified in
SYSTEMD_SERVICE
should be started automatically or not.
By default, the service is enabled to automatically start
at boot time.
The default setting is in the
systemd
class as follows:
SYSTEMD_AUTO_ENABLE ??= "enable"
You can disable the service by setting the variable to "disable."
For recipes that inherit the
systemd
class, this variable locates the systemd unit files when
they are not found in the main recipe's package.
By default, the
SYSTEMD_PACKAGES
variable is set
such that the systemd unit files are assumed to reside in
the recipes main package:
SYSTEMD_PACKAGES ?= "${PN}"
If these unit files are not in this recipe's main
package, you need to use
SYSTEMD_PACKAGES
to list the package
or packages in which the build system can find the systemd
unit files.
For recipes that inherit the
systemd
class, this variable specifies the systemd service name for
a package.
When you specify this file in your recipe, use a package name override to indicate the package to which the value applies. Here is an example from the connman recipe:
SYSTEMD_SERVICE_${PN} = "connman.service"
This variable points to a directory were BitBake places temporary files, which consist mostly of task logs and scripts, when building a particular recipe. The variable is typically set as follows:
T = "${WORKDIR}/temp"
The WORKDIR
is the directory into which BitBake unpacks and builds the
recipe.
The default bitbake.conf
file sets this variable.
The T
variable is not to be confused with
the TMPDIR
variable,
which points to the root of the directory tree where BitBake
places the output of an entire build.
The target machine's architecture. The OpenEmbedded build system supports many architectures. Here is an example list of architectures supported. This list is by no means complete as the architecture is configurable:
arm i586 x86_64 powerpc powerpc64 mips mipsel
Flags passed to the C compiler for the target system.
This variable evaluates to the same as
CFLAGS
.
Specifies the method for handling FPU code. For FPU-less targets, which include most ARM CPUs, the variable must be set to "soft". If not, the kernel emulation gets used, which results in a performance penalty.
Specifies the target's operating system.
The variable can be set to "linux" for eglibc
-based systems and
to "linux-uclibc" for uclibc
.
For ARM/EABI targets, there are also "linux-gnueabi" and
"linux-uclibc-gnueabi" values possible.
Specifies which variant of the GNU standard C library (libc
)
to use during the build process.
This variable replaces POKYLIBC
, which is no longer
supported.
You can select eglibc
or uclibc
.
glibc
implementation of libc
.
The toolchain selector.
This variable replaces POKYMODE
, which is no longer
supported.
The TCMODE
variable selects the external toolchain
built using the OpenEmbedded build system or a few supported combinations of
the upstream GCC or CodeSourcery Labs toolchain.
The variable identifies the tcmode-*
files used in
the meta/conf/distro/include
directory, which is found in the
Source Directory.
By default, TCMODE
is set to "default", which
chooses the tcmode-default.inc
file.
The variable is similar to
TCLIBC
, which controls
the variant of the GNU standard C library (libc
)
used during the build process: eglibc
or uclibc
.
Automatically runs the series of automated tests for images when an image is successfully built.
These tests are written in Python making use of the
unittest
module, and the majority of
them run commands on the target system over
ssh
.
You can set this variable to "1" in your
local.conf
file in the
Build Directory
to have the OpenEmbedded build system automatically run
these tests after an image successfully builds:
TEST_IMAGE = "1"
For more information on enabling, running, and writing
these tests, see the
"Performing Automated Runtime Testing"
section in the Yocto Project Development Manual and the
"testimage.bbclass
"
section.
The time in seconds allowed for an image to boot before
automated runtime tests begin to run against an
image.
The default timeout period to allow the boot process to
reach the login prompt is 500 seconds.
You can specify a different value in the
local.conf
file.
For more information on testing images, see the "Performing Automated Runtime Testing" section in the Yocto Project Development Manual.
An ordered list of tests (modules) to run against an image when performing automated runtime testing.
The OpenEmbedded build system provides a core set of tests that can be used against images.
Tests include ping
,
ssh
, df
among
others.
You can add your own tests to the list of tests by
appending TEST_SUITES
as follows:
TEST_SUITES_append = " mytest"
Alternatively, you can provide the "auto" option to have all applicable tests run against the image.
TEST_SUITES_append = " auto"
Using this option causes the build system to automatically run tests that are applicable to the image. Tests that are not applicable are skipped.
The order in which tests are run is important.
Tests that depend on another test must appear later in the
list than the test on which they depend.
For example, if you append the list of tests with two
tests (test_A
and
test_B
) where
test_B
is dependent on
test_A
, then you must order the tests
as follows:
TEST_SUITES = " test_A test_B"
For more information on testing images, see the "Performing Automated Runtime Testing" section in the Yocto Project Development Manual.
The directory in which the file BitBake is currently parsing is located. Do not manually set this variable.
This variable is the base directory the OpenEmbedded
build system uses for all build output and intermediate
files (other than the shared state cache).
By default, the TMPDIR
variable points
to tmp
within the
Build Directory.
If you want to establish this directory in a location other
than the default, you can uncomment and edit the following
statement in the
conf/local.conf
file in the
Source Directory:
#TMPDIR = "${TOPDIR}/tmp"
This variable lists packages the OpenEmbedded build system
uses when building an SDK, which contains a
cross-development environment.
The packages specified by this variable are part of the
toolchain set that runs on the
SDKMACHINE
,
and each package should usually have the prefix
"nativesdk-".
When building an SDK using
bitbake -c populate_sdk <imagename>
,
a default list of packages is set in this variable, but
you can add additional packages to the list.
For background information on cross-development toolchains in the Yocto Project development environment, see the "Cross-Development Toolchain Generation" section. For information on setting up a cross-development environment, see the "Installing the ADT and Toolchains" section in the Yocto Project Application Developer's Guide.
This variable lists packages the OpenEmbedded build system uses when it creates the target part of an SDK (i.e. the part built for the target hardware), which includes libraries and headers.
For background information on cross-development toolchains in the Yocto Project development environment, see the "Cross-Development Toolchain Generation" section. For information on setting up a cross-development environment, see the "Installing the ADT and Toolchains" section in the Yocto Project Application Developer's Guide.
This variable points to the Build Directory. BitBake automatically sets this variable.
A sanitized version of
TARGET_ARCH
.
This variable is used where the architecture is needed in
a value where underscores are not allowed, for example
within package filenames.
In this case, dash characters replace any underscore
characters used in TARGET_ARCH.
Do not edit this variable.
The package architecture understood by the packaging system to define the architecture, ABI, and tuning of output packages.
Configures the
UBOOT_MACHINE
and can also define
IMAGE_FSTYPES
for individual cases.
Following is an example from the
meta-fsl-arm
layer.
UBOOT_CONFIG ??= "sd" UBOOT_CONFIG[sd] = "mx6qsabreauto_config,sdcard" UBOOT_CONFIG[eimnor] = "mx6qsabreauto_eimnor_config" UBOOT_CONFIG[nand] = "mx6qsabreauto_nand_config,ubifs" UBOOT_CONFIG[spinor] = "mx6qsabreauto_spinor_config"
In this example, "sd" is selected as the configuration
of the possible four for the
UBOOT_MACHINE
.
The "sd" configuration defines "mx6qsabreauto_config"
as the value for UBOOT_MACHINE
, while
the "sdcard" specifies the
IMAGE_FSTYPES
to use for the U-boot
image.
For more information on how the
UBOOT_CONFIG
is handled, see the
uboot-config
class.
Specifies the entry point for the U-Boot image.
During U-Boot image creation, the
UBOOT_ENTRYPOINT
variable is passed
as a command-line parameter to the
uboot-mkimage
utility.
Specifies the load address for the U-Boot image.
During U-Boot image creation, the
UBOOT_LOADADDRESS
variable is passed
as a command-line parameter to the
uboot-mkimage
utility.
Appends a string to the name of the local version of the U-Boot image. For example, assuming the version of the U-Boot image built was "2013.10, the full version string reported by U-Boot would be "2013.10-yocto" given the following statement:
UBOOT_LOCALVERSION = "-yocto"
Specifies the value passed on the
make
command line when building
a U-Boot image.
The value indicates the target platform configuration.
You typically set this variable from the machine
configuration file (i.e.
conf/machine/<machine_name>.conf
).
Specifies the target called in the
Makefile
.
The default target is "all".
Points to the generated U-Boot extension.
For example, u-boot.sb
has a
.sb
extension.
The default U-Boot extension is
.bin
Specifies the target used for building U-Boot. The target is passed directly as part of the "make" command (e.g. SPL and AIS). If you do not specifically set this variable, the OpenEmbedded build process passes and uses "all" for the target during the U-Boot building process.
A list of classes to globally inherit.
These classes are used by the OpenEmbedded build system
to enable extra features (e.g.
buildstats
,
image-mklibs
, and so forth).
The default list is set in your
local.conf
file:
USER_CLASSES ?= "buildstats image-mklibs image-prelink"
For more information, see
meta-yocto/conf/local.conf.sample
in
the
Source Directory.
When a recipe inherits the
useradd
class, this variable
specifies the individual packages within the recipe that
require users and/or groups to be added.
You must set this variable if the recipe inherits the class. For example, the following enables adding a user for the main package in a recipe:
USERADD_PACKAGES = "${PN}"
USERADD_PACKAGES
variable,
you need to set one or more of the
USERADD_PARAM
,
GROUPADD_PARAM
,
or
GROUPMEMS_PARAM
variables.
When a recipe inherits the
useradd
class, this variable
specifies for a package what parameters should be passed
to the useradd
command
if you wish to add a user to the system when the package
is installed.
Here is an example from the dbus
recipe:
USERADD_PARAM_${PN} = "--system --home ${localstatedir}/lib/dbus \ --no-create-home --shell /bin/false \ --user-group messagebus"
For information on the standard Linux shell command
useradd
, see
http://linux.die.net/man/8/useradd.
Specifies the quality assurance checks whose failures are
reported as warnings by the OpenEmbedded build system.
You set this variable in your distribution configuration
file.
For a list of the checks you can control with this variable,
see the
"insane.bbclass
"
section.
The pathname of the work directory in which the OpenEmbedded build system
builds a recipe.
This directory is located within the
TMPDIR
directory structure and changes
as different packages are built.
The actual WORKDIR
directory depends on several things:
For packages that are not dependent on a particular machine,
WORKDIR
is defined as follows:
${TMPDIR}/work/${PACKAGE_ARCH}-poky-${TARGET_OS}/${PN}/${PV}-${PR}
As an example, assume a
Source Directory top-level
folder name poky
and a default
Build Directory
at poky/build
.
In this case, the work directory the build system uses to build
the v86d
package is the following:
poky/build/tmp/work/qemux86-poky-linux/v86d/01.9-r0
For packages that are dependent on a particular machine, WORKDIR
is defined slightly differently:
${TMPDIR}/work/${MACHINE}-poky-${TARGET_OS}/${PN}/${PV}-${PR}
As an example, again assume a Source Directory top-level folder
named poky
and a default Build Directory
at poky/build
.
In this case, the work directory the build system uses to build
the acl
recipe, which is being built for a
MIPS-based device, is the following:
poky/build/tmp/work/mips-poky-linux/acl/2.2.51-r2