Bitbake & OpenEmbedded Overview

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bitbake

Using OpenEmbedded on Linux systems

Bitbake Tutorial

Image Types and Bitbake Targets

OpenEmbedded Directory Layout

Variable

# Path prefixes
export base_prefix = ""
export prefix = "/usr"
export exec_prefix = "/usr"

# Base paths
export base_bindir = "${base_prefix}/bin"
export base_sbindir = "${base_prefix}/sbin"
export base_libdir = "${base_prefix}/lib"

# Architecture independent paths
export datadir = "${prefix}/share"
export sysconfdir = "${base_prefix}/etc"
export servicedir = "${base_prefix}/srv"
export sharedstatedir = "${base_prefix}/com"
export localstatedir = "${base_prefix}/var"
export infodir = "${datadir}/info"
export mandir = "${datadir}/man"
export docdir = "${datadir}/doc"
.....
##################################################################
# Download locations and utilities.
##################################################################

OE_STRICT_CHECKSUMS ?= "1"

ADOBE_MIRROR = "http://fpdownload.macromedia.com/get/flashplayer/current/"
APACHE_MIRROR = "http://archive.apache.org/dist"
DEBIAN_MIRROR = "ftp://ftp.debian.org/debian/pool"
E_MIRROR = "http://download.enlightenment.org/releases"
E_SVN = "svn://svn.enlightenment.org/svn/e"
FREEBSD_MIRROR = "ftp://ftp.freebsd.org/pub/FreeBSD/"
FREEDESKTOP_CVS = "cvs://anoncvs:anoncvs@anoncvs.freedesktop.org/cvs"
FREESMARTPHONE_GIT = "git://git.freesmartphone.org"
GENTOO_MIRROR = "http://distfiles.gentoo.org/distfiles"
GNOME_GIT = "git://git.gnome.org"
...

conf/documentation.conf

OpenEmbedded HowTo

• Bitbake
  
  • Examples
    

    A bitbake nano will parse all *.bb files defined in local.conf, build a hash and build everything, which nano depends on and last but not least nano itself.

    A bitbake -c clean nano will clean the nano package.

    A bitbake -b whereYourOEPackageDirIsbitbake/nano/nano₁.3.5.bb / will just build nano. All depends have already to be fullfilled for that. This does not execute the bb file parsing and spares time (e.g. during debugging).

    A bitbake -b whereYourOEPackageDirIsbitbake/nano/nano₁.3.5.bb -f -c clean / will force a clean on the already builded nano package.

    A bitbake -b whereYourOEPackageDirIsbitbake/nano/nano₁.3.5.bb -f -c fetch / will force a fetch on the already builded nano package. The package source is downloaded again independent of the cache status.

    A bitbake -b whereYourOEPackageDirIsbitbake/nano/nano₁.3.5.bb -f -c build / will force a build on the nano package. This will execute all stages "before" compile like fetch, patch, configure … and compile itself.

    A bitbake -D -D -D nano will build the nano package and show you all files parsed.

    A bitbake virtual/kernel -c clean; bitbake virtual/kernel builds a new kernel for the opie-image and afterwards the related image.

• How the configuration works
  

  An example is described in the following list.

  • openembedded/conf/bitbake.conf This is where all parsing starts.
  • YourBuildDir/conf/local.conf Here you can do you local configuration. Most interesting options are MACHINE and DISTRO. A TARGET_OS or TARGET_ARCH are normally defined somewhere deeper in the conf tree.
  • openembedded/conf/machine/YourDefinedMachine.conf And all included machine_xxx.conf files. Here the HW-dependend options (kernel, etc …) are defined.
  • openembedded/conf/distro/YourDefinedDistro.conf And all included YourDefinedDistro_xxx.conf files (mostly none). Here the Distro dependend options are defined.
  • All BBFILES defined .bb files This is the final run.
• Cleaning
  

  For example a qte rebuild needs

  cd tmp/work
  rm -rf *opie*
  rm -rf libopie*
  rm -rf libq*
  rm -rf *qte*
  cd tmp/cache
  rm -rf *opie*
  rm -rf *libopie*
  rm -rf *libq*
  rm -rf *qte*
  cd tmp/stamps
  rm -rf *opie*
  rm -rf libopie*
  rm -rf libq*
  rm -rf *qte*
  

  before rebuilding.

• Debugging
  
  • Debugging output (-D) One option to get more information on the build process is to use additionally the -D option. This option may occur multiple times and thus increases the DebugLevel.

  bitbake -D -D -D nano
  

  • Show environment -e The option -e shows the environment variables set during a bitbake run.

  bitbake -e nano
  

  • Show package versions -s
  • Dry run -n The dry run can be used to check, whether all dependencies are fullfilled. Also versioning, etc. can be checked.
• Using the tmp/deploy/ipk dir as your local repository
  

  #!/bin/sh
  
  TFILE="doit.rc"
  rm -f ${TFILE}
  rm -f Packages.new
  
  echo -n "finding packages ... "
  find *.ipk | \
          awk --traditional '{ printf( "echo -n .;ar -p %s control.tar.gz", $1 );
                               printf( " | tar -xzO ./control >> Packages.new;" );
                               printf( "echo Filename: %s >> Packages.new;", $1 );
                               printf( "echo Size: %s >> Packages.new;", $1 );
                               printf( "echo >> Packages.new\n" ); }' >> ${TFILE}
  echo `cat doit.rc | wc -l` found.
  /bin/sh ${TFILE}
  

• Clean Package Dependends
  

  do\_clean.rc

  #!/bin/sh
  # V0.1.0
  # Used to clean up OE package dependencies.
  # Note, that all recursive dependencies are cleaned.
  
  PAC=${1}
  DEPLIST=""
  DEPCNT="0"
  
  usage()
  {
          echo "usage : ${0} path/to/xx.bb"
          echo "        cleans all xx.bb dependend packages"
  }
  
  get_args()
  {
          if [ "${PAC}" == "" ]; then
                  usage
                  exit 1;
          fi
  
  }
  
  get_deps()
  {
          DEPLIST=`bbread ${PAC} | grep -E -i -e "^DEPENDS=" | sed -e 's/.*=\"//'`
          DEPLIST=`echo ${DEPLIST} | sed -e 's/\"//'`
          SELF=`echo ${PAC} | sed -e 's/\.bb$//'`
          SELF=`echo ${SELF} | sed -e 's/.*\///'`
          SELF=`echo ${SELF} | sed -e 's/_.*$//'`
          DEPLIST="${DEPLIST} ${SELF}"
          DEPCNT=`echo ${DEPLIST} | wc -w`
          echo found ${DEPCNT} dependend packages.
  }
  
  askme()
  {
          TMP=""
          TR="1"
  
          for r in ${DEPLIST}; do
                  if [ "${TR}" != "" ]; then
                          echo -n "Clean '${r}' Yes/(N)o/Rest ? : "
                          read aa
                  fi
                  case "${aa}" in
                          Y )
                          TMP="${TMP} ${r}"
                          ;;
                          R )
                          TR=""
                          TMP="${TMP} ${r}"
                          ;;
                  esac
          done
  
          DEPLIST=${TMP}
          DEPCNT=`echo ${DEPLIST} | wc -w`
  }
  
  grepit()
  {
          echo -n "Enter a : pattern to grep  "
          read REGI
  
          TMP=""
          for r in ${DEPLIST}; do
                  s=`echo ${r} | grep -v ${REGI}`
                  TMP="${TMP} ${s}"
          done
  
          DEPLIST=${TMP}
          DEPCNT=`echo ${DEPLIST} | wc -w`
  }
  
  ask_user()
  {
          if [ "${DEPCNT}" == "0" ]; then
                  echo "Nothing to clean ;-)"
                  exit 0
          fi
  
          echo Really clean the following packages ?
          echo "======================================================="
          echo ${DEPLIST}
          echo "======================================================="
          echo -n "Yes/(N)o/Askme/Grep : "
          read aa
  
          case "${aa}" in
                  Y )
                          ;;
                  G )
                          grepit
                          ask_user
                          ;;
                  A )
                          askme
                          ask_user
                          ;;
                  * )
                          echo "aborted :-("
                          exit 1
                          ;;
          esac
  }
  
  doit()
  {
          echo
          echo -n cleaning, please wait 
          bitbake -c clean ${DEPLIST}
  }
  
  get_args
  get_deps
  ask_user
  doit
  

  • use

  $ do_clean.rc ../openembedded/packages/meta/opie-image.bb
  

• Customize to you needs
  
  • Adding another package repository
    

    The new BBFILES line(s) are e.g.

    BBFILES := "${HOME}/dev/oe/org.openembedded.dev/packages/*/*.bb"
    BBFILES += "${HOME}/myoe/packages/*/*.bb"
    

  • Adding a new machine
    
  • Adding a new distro
    
  • Adding a new bootstrap-image
    
  • Build the above mentioned bootstrap-image
    
  • Example : Adding a new package (from existing sources)
    

    Info: Preparing the Makefile

    This subsection describes the changes I had to do on the Makefile and the way to create and provide an appropriate patch.

    Unpack the sources tgz or the cvs dir into your patch dir and create a copy of the resulting dir named xxx_orig.
    Edit the non _orig's Makefile.
    Remove (or comment) the CC entry to force CROSS usage
    Remove (or comment) the CFLAGS entry to force bitbake CFLAGS usage.
    Note, that this may be wrong, when non standard entries need to be provided. Change the CFLAGS to e.g. CYFLAGS entry in the complete Makefile in this case.
    Added $(DESTDIR) to the PRFIX variable to cause make to install binaries to the ${D} dir instead to /
    Potentially you do not want to install something like includ or man pages.
    remove that targets from Makefile then.
    Create a patch calling diff -Naur xxx xxx_orig > xxx_make.patch where xxx is your packages dir name.
    Copy that patch to myoe/packages/schedutils/schedutils dir (matching the SRC_URI's patch entry described above ).
    

    Done that changes, you have the chance to build your new package.

• FAQ
  
  • During build process, a package complains not to find shared libs for installation
    

    This occured e.g. with the readline package for opie image. I did not find out, why this happens. The possible solution (at least it works on my system) is a manual (non bitbake) make clean;./configure and afterwards a bitbake -b ../.../readline_x.y.bb -c build. It seems to have something to do with the configuration phase of bitbake for this package.

  • How can I add a customized /etc/fstab ?
    

    /oe/sources/openembedded/recipes/base-files/base-files/fstab