Common Use-cases/tasksCreating a new DistributionCreating a new distribution is not complicated, however we urge you
to try existing distributions first, because it's also very easy to do
wrong. The config need to be created in /conf/distro directory. So what
has to be inside? DISTRO_VERSION so users will know which
version of distribution they use.DISTRO_TYPE (release/debug) variable is
used in some recipes to enable/disable some features - for example
kernel output on screen for "debug" builds.Type of libc used: will it be glibc
(TARGET_OS = "linux") or uclibc
(TARGET_OS = "linux-uclibc")?Toolchain versions - for example gcc 3.4.4 based distro will
have:
PREFERRED_PROVIDERS += " virtual/${TARGET_PREFIX}gcc-initial:gcc-cross-initial"
PREFERRED_PROVIDERS += " virtual/${TARGET_PREFIX}gcc:gcc-cross"
PREFERRED_PROVIDERS += " virtual/${TARGET_PREFIX}g++:gcc-cross"
PREFERRED_VERSION_binutils = "2.16"
PREFERRED_VERSION_binutils-cross = "2.16"
PREFERRED_VERSION_gcc = "3.4.4"
PREFERRED_VERSION_gcc-cross = "3.4.4"
PREFERRED_VERSION_gcc-initial-cross = "3.4.4"
DISTRO_FEATURES which describe which
features distro has. More about it in task-base section.Versions of kernels used for supported devices:
PREFERRED_VERSION_linux-omap1_omap5912osk ?= "2.6.18+git"
PREFERRED_VERSION_linux-openzaurus ?= "2.6.17"
To get more stable build it is good to make use of
sane-srcdates.inc file which contain working SRCDATE for many of
floating recipes.
require conf/distro/include/sane-srcdates.inc
It also should have global SRCDATE
value set (format is ISO date: YYYYMMDD):
SRCDATE = "20061014"
Adding a new MachineTo be able to build for device OpenEmbedded have to know it, so
machine config file need to be written. All those configs are stored in
/conf/machine/ directory.As usual some variables are required: TARGET_ARCH which describe which CPU
architecture does machine use.MACHINE_FEATURES which describe which
features device has. More about it in task-base section.PREFERRED_PROVIDER_virtual/kernel has to
point into proper kernel recipe for this machine.Next kernel recipe needs to be added.Adding a new PackageThis section is a stub, help us by expanding it. Learn by example, go through the
recipes that are already there and mimic them to do what you want.building from unstable source codeBuilding against the latest, bleeding-edge source has some intricacies of its own.
For one, it is desirable to pin down a souce code revision that is known to build to
prevent random breakage in OE at the most inopportune time for all OE users. Here is
how to do that properly.
for svn: add 'PV = "1.1+svnr${SRCREV}"' to your bb file.for cvs: add 'PV = "1.1+cvs${SRCREV}"' to your bb file.
Accompany either with an entry to conf/distro/include/sane-srcrevs.inc for a revision that you know
builds successfully.
If you really absolutely have to follow the latest commits, you can do that by adding
'SRCREV_pn-linux-davinci ?= ${AUTOREV}' to your local.conf, for example. In this case,
you'd build against the most recent and unstable source for the pn-linux-davinci package.
Creating your own imageCreating own image is easy - only few variables needs to be set:
IMAGE_BASENAME to give a name for your own
imagePACKAGE_INSTALL to give a list of packages
to install into the imageRDEPENDS to give a list of recipes which
are needed to be built to create this imageIMAGE_LINGUAS is an optional list of
languages which has to be installed into the image Then adding of the image class use:
inherit image
And the image recipe is ready for usage.Using a prebuilt toolchain to create your packagesIt might be necessary to integrate a prebuilt toolchain and other
libraries but still be use OpenEmbedded to build packages. One of many
approaches is shown and discussed here.The toolchainWe assume the toolchain provides a C and C++ compiler, an
assembler and other tools to build packages. The list below shows a gcc
3.4.4 toolchain for ARM architectures using glibc. We assume that the
toolchain is in your PATH.ls pre-built/cross/bin
arm-linux-g++
arm-linux-ld
arm-linux-ranlib
arm-linux-ar
arm-linux-g77
arm-linux-readelf
arm-linux-as
arm-linux-gcc
arm-linux-gcc-3.4.4
arm-linux-c++
arm-linux-size
arm-linux-c++filt
arm-linux-nm
arm-linux-strings
arm-linux-cpp
arm-linux-objcopy
arm-linux-strip
arm-linux-objdump
The prebuilt librariesWe need the header files and the libraries itself. The following
directory layout is assumed. PRE_BUILT has two
subdirectories one is called include and holds the
header files and the other directory is called lib
and holds the shared and static libraries. Additionally a Qt2 directory
is present having a include and
lib sub-directory.ls $PRE_BUILT
include
lib
qt2
Setting up OpenEmbeddedOpenEmbedded will be setup here. We assume that your machine and
distribution is not part of OpenEmbedded and they will be created ad-hoc
in the local.conf file. You will need to have
BitBake and a current OpenEmbedded version
available.Sourcable scriptTo ease the usage of OpenEmbedded we start by creating a
source-able script. This is actually a small variation from the
already seen script. We will name it build_source
and you will need to source it.
BITBAKE_PATH=/where/is/bitbake/bin
TOOLCHAIN=/where/is/toolchain/bin
HOST_TOOLS=/where/is/hosttools/bin
export PRE_BUILT=/where/is/pre-built
export PATH=$BITBAKE_PATH:$TOOLCHAIN:$HOST_TOOLS:$PATH
export OEDIR=$PWD
export LOCALDIR=$PWD/secret-isv
Use source build_source to source the script,
use env to check that the variable where
exported.Creating the local.confWe will configure OpenEmbedded now, it is very similar to what
we have done above.
DL_DIR = "${OEDIR}/sources"
BBFILES := "${OEDIR}/openembedded/recipes/*/*.bb ${LOCALDIR}/recipes/*/*.bb"
BBFILE_COLLECTIONS = "upstream local"
BBFILE_PATTERN_upstream = "^${OEDIR}/openembedded/recipes/"
BBFILE_PATTERN_local = "^${LOCALDIR}/recipes/"
BBFILE_PRIORITY_upstream = "5"
BBFILE_PRIORITY_local = "10"
BBMASK = ""
${OEDIR}/openembedded will be a upstream release of
OpenEmbedded. Above we have assumed it is in the current working
directory. Additionally we have a ${LOCALDIR}, we combine these two
directories as a special BitBake
Collection.
#
# machine stuff
#
MACHINE = "secret-killer"
PACKAGE_EXTRA_ARCHS = "armv4 armv4t armv5te iwmmxt xscale""
TARGET_CC_ARCH = "-mcpu=xscale -mtune=iwmmxt"
TARGET_ARCH = "arm"
PACKAGE_ARCH="xscale"
We tell OpenEmbedded that we build for the ARM platform and
optimize for xscale and iwmmxt.
INHERIT += " package_ipk debian"
TARGET_OS = "linux"
TARGET_FPU = "soft"
DISTRO = "secret-disro"
DISTRO_NAME = "secret-distro"
DISTRO_VERSION = "x.y.z"
DISTRO_TYPE = "release"
Create a distribution ad-hoc as well. We tell OpenEmbedded that
we build for linux and glibc using soft float as fpu. If your
toolchain is a uclibc toolchain you will need to set
TARGET_OS to linux-uclibc.
export CC="${CCACHE}arm-linux-gcc-3.4.4 ${HOST_CC_ARCH}"
export CXX="${CCACHE}arm-linux-g++ ${HOST_CC_ARCH}"
export CPP="arm-linux-gcc-3.4.4 -E"
export LD="arm-linux-ld"
export AR="arm-linux-ar"
export AS="arm-linux-as"
export RANLIB="arm-linux-ranlib"
export STRIP="arm-linux-strip"
The above variables replace the ones from
bitbake.conf. This will make OpenEmbedded use the
prebuilt toolchain.
#
# point OE to the lib and include directory
#
TARGET_CPPFLAGS_append = " -I${PRE_BUILT}/include "
TARGET_LDFLAGS_prepend = " -L${PRE_BUILT}/qt2/lib -L${PRE_BUILT}/lib \
-Wl,-rpath-link,${PRE_BUILT}/lib -Wl,-rpath-link,${PRE_BUILT}/qt2/lib "
# special to Qt/Qtopia
QTDIR = "${PRE_BUILT}/qt2"
QPEDIR = "${PRE_BUILT}"
palmtopdir = "/opt/Qtopia"
palmqtdir = "/opt/Qtopia"
We will add the PRE_BUILT libraries to the
include and library paths. And the same is done for the special
version of Qt we have in your PRE_BUILT
directory.
ASSUME_PROVIDED += " virtual/${TARGET_PREFIX}gcc "
ASSUME_PROVIDED += " virtual/libc "
ASSUME_PROVIDED += " virtual/qte "
ASSUME_PROVIDED += " virtual/libqpe "
ASSUME_PROVIDED += " libqpe-opie "
Now we have told BitBake that the C
library, compiler and Qtopia is already provided. These lines will
avoid building binutils, gcc initial, glibc, gcc.source build_source
bitbake your-killer-app
You should be able to create the packages you want to using the
prebuilt toolchain now.Useful hintsIf you have more prebuilt libraries you need to add additional
ASSUME_PROVIDED lines to your
local.conf. Using bitbake -vvv
PACKAGE you can easily see the package names you could
ASSUME_PROVIDED if you have some prebuilt.Issues with this approach
NOTE: Couldn't find shared library provider for libqtopia.so.1
NOTE: Couldn't find shared library provider for libqtopia2.so.2
NOTE: Couldn't find shared library provider for libqpe.so.1
NOTE: Couldn't find shared library provider for libpthread.so.0
NOTE: Couldn't find shared library provider for libstdc++.so.6
NOTE: Couldn't find shared library provider for libqte.so.2
NOTE: Couldn't find shared library provider for libgcc_s.so.1
NOTE: Couldn't find shared library provider for libc.so.6
NOTE: Couldn't find shared library provider for libm.so.6
OpenEmbedded tries to automatically add run-time dependencies
(RDEPENDS) to generated packages. It is inspecting binaries and
libraries and uses the shlibs
system to do add dependencies for the linked libaries,
however in this case it was not able to find packages providing these
libraries as they were prebuilt.
One way to resolve this problem is to provide an explicit mapping
using the ASSUME_SHLIBS variable in a config file local.conf.
For example, for the libraries above (partial):
ASSUME_SHLIBS = "libqtopia2.so.2:qtopia2_2.4 libc.so.6:libc"
The format is shlib_file_name:package[_version]. If a version is specified it will be
used as the minimal (>=) version for the dependency.Using a new package formatThis section is a stub, help us by expanding it