Yocto Packages
Please read the great Yocto Reference manual before proceeding:
Often a developer will want to add a new package such as tcpdump or openvpn, or other standard packages.
There are presumably many ways to do this, some of which are better than others.
GUI Method
A GUI for bitbake is called Hob. See more information here
Package Feed types
Note that packages are split into feeds based on their type called 'feeds'
On the target, the /etc/opkg/arch.conf file lists all types appropriate for your target and prioritizes them in case a package exists in multiple feeds.
On the build host, packages are placed into directories for each feed.
Some examples of standard feeds include:
- all - packages that are applicable for all targets (ie scripts, text files, cross-platform data files)
- armv7a - packages that are applicable for the armv7a instruction set only (ie compiled applications)
- armv7a-vfp-neon - packages that are applicable for the armv7a instruction set using NEON hardware floating point
- ventana - packages that are applicable to the ventana machine target (ie kernel and kernel modules)
Package Building (using bitbake)
The following steps provide an example of building a package (in this case e2fsprogs):
- Find package you want. You can use bitbake-layers show-recipes to search for packages:
$ bitbake-layers show-recipes | grep e2f Parsing recipes..done. meta 1.8.2+git1+e398e374e2ff0e88bc1d63577a192f8ca04a1cb5 e2fsprogs: meta 0.1+git1+a0be2fe4b5f12b8b07f4e3bd624b3729657f0ac5
- Compile and build package with bitbake command. Example shown:
$ bitbake e2fsprogs
- Find outputted compiled .ipk file in one of the folders inside the ipk directory. Example shown:
$ ls build/tmp/deploy/ipk all armv7a-vfp-neon Packages Packages.flock Packages.gz Packages.stamps ventana
This case
$ ls build/tmp/deploy/ipk/armv7a-vfp-neon/e2fsprogs-mke2fs_1.42.1-r4_armv7a-vfp-neon.ipk
Installing packages onto target (manually one at a time)
- Transfer desired .ipk file to Gateworks board that is running Yocto already. Use a tool such as wget.
- Use the opkg install command to install on target. Example shown:
root@ventana:~# opkg install e2fsprogs-mke2fs_1.42.1-r4_armv7a-vfp-neon.ipk
2a. This case there was a error because this package has dependencies that are not installed. Please install these first!root@ventana:~# opkg install e2fsprogs-mke2fs_1.42.1-r4_armv7a-vfp-neon.ipk Installing e2fsprogs-mke2fs (1.42.1-r4) to root... Collected errors: * satisfy_dependencies_for: Cannot satisfy the following dependencies for e2fsprogs-mke2fs: * libcom-err2 (>= 1.42.1) * libe2p2 (>= 1.42.1) * libext2fs2 (>= 1.42.1) * * opkg_install_cmd: Cannot install package e2fsprogs-mke2fs.
2b. After installing the dependencies, try againroot@ventana:~# opkg install e2fsprogs-mke2fs_1.42.1-r4_armv7a-vfp-neon.ipk Installing e2fsprogs-mke2fs (1.42.1-r4) to root... Configuring e2fsprogs-mke2fs. root@ventana:~#
- Test package / command . Example shown
root@ventana:~# mk mkdir mkfs.ext2 mkfs.ext4dev mkfs.ubifs mktemp mke2fs mkfs.ext3 mkfs.jffs2 mknod mkfifo mkfs.ext4 mkfs.minix mkswap root@ventana:~# mkfs.ext4 Usage: mkfs.ext4 [-c|-l filename] [-b block-size] [-C cluster-size] [-i bytes-per-inode] [-I inode-size] [-J journal-options] [-G flex-group-size] [-N number-of-inodes] [-m reserved-blocks-percentage] [-o creator-os] [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory] [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]] [-t fs-type] [-T usage-type ] [-U UUID] [-jnqvFKSV] device [blocks-count]
Installing using package feeds
Setting up a package feed is the easiest way to install packages, but it does require setting up a web server on your build host and adding in a feed conf file.
Procedure:
- Install and configure a web server on your build host. For example, to install and configure 'lighttpd' on ubuntu:
# install the package $ sudo apt-get install lighttpd # add an alias for 'yocto' to your build hosts directory: $ sudo sh -c 'echo "alias.url += ( \"/yocto\" => \"/usr/src/yocto/build/tmp/deploy/ipk\" )" >> /etc/lighttpd/lighttpd.conf'
- On your target, point to the various feeds on your hosts build directory. For example, if your build host is at 192.168.1.1 and you setup the aliase above as 'yocto' to point to your build/tmp/deploy/ipk directory:
root@ventana:~# cat << EOF > /etc/opkg/base-feeds.conf # non-arch dependent files (scripts, config etc) src/gz all http://192.168.1.1/yocto/all # arch dependent files src/gz armv7a-vfp-neon http://192.168.1.1/yocto/armv7a-vfp-neon # machine dependent files (kernel, modules) src/gz imx6qsabresd http://192.168.1.1/yocto/ventana EOF
- update your feeds and install:
root@ventana:~# opkg update root@ventana:~# opkg install e2fsprogs-mke2fs
- you will need to update your feeds with 'opkg update' each time they change on your build host (ie you have built something new)
Package Development Workflow
A common question is 'how do I develop or modify a package in the bitbake environment'. Here is a step-by-step procedure that may prove useful as a guide:
- Create a new package (if not modifying an existing one)
- activate a bitbake shell and build the package (performs all necessary steps per package recipe to fetch,patch,configure,compile,install,package and results in an ipk in build/tmp/deploy)
bitbake <package>
- edit source in packages WORKDIR
- This will be in build/tmp/work in a subdirectory based on the feed for that package. For example packages that are independent of architecture, machine, etc (ie shell scripts, text files) will be in tmp/work/all-poky/linux and packages that are independent of machine but dependent on architecture (ie compiled apps or libs) will be in an arch specific subdir such as tmp/work/cortexa9hf-vfp-neon-poky-linux-gnueabi and packages that depend on the 'ventana' machine such as the kernel or kernel modules, will be in the tmp/work/ventana-poky-linux-gnueabi subdir.
- force bitbake (-f flag) to re-execute the 'compile' task (-ccompile) as bitbake won't know that source files have been changed in the WORKDIR and 'bitbake <package>' will think its already done
bitbake -f -ccompile <package>
- this forces all tasks dependent on the 'compile' tasks will now be flagged as dirty
- if you are copying build objects to your target manually from the package WORKDIR you can do that now, and simply repeat steps 3 and 4 until you are done with your development
- bitbake the package to complete all remaining tasks to create an ipk
bitbake <package>
- if using opkg to get the updated package on your target, update the package indexes
bitbake package-index
- if only using opkg for package updates you can now repeat steps 3, 4, 5, and 6 until you are done with your development
- if re-flashing the filesystem image rebuild that as well:
bitbake gateworks-image-test
- Note that bitbake stores filesystem images in the DEPLOY directory by timestamp, and they will never be removed. You may want to 'rm -rf tmp/deploy/images/ventana/gateworks-image-test*' prior to rebuilding to keep disk space down
- if using ubi filesystem for package updates you can now repeat steps 3, 4, 5, 6, and 7 until you are done with your development
If you are ultimately trying to produce a patch that will persist for the package you will want to use something like 'quilt' to track your patch in step 3. Then, when your development cycle is complete you can:
- take the resulting patch(es) produced by quilt and place them in an appropriate directory for that package (something thats in the filespath)
- add the patches to the SRC_URI of the package
- bump the package revision (PR) (or equivalent) so that bitbakes dependency system knows the package needs to be rebuilt in its entirety
- push your new recipe to your version control subsystem (or share it via mailist or public repository)
Alternatively if you are trying to 'upstream' your patches (which you should do to avoid future maintenance on your part):
- take the resulting patch(es) produced by quilt and submit them to the projects mailist
- once your patches are upstreamed you can update the package recipe SRCREV to pull the updated version from source control (or create a new recipe if appropriate). If you create a new recipe (because the version of the package changes) or bump the SRCREV (because the recipe pulls 'un-released' source from a source control repository) you don't need to bump the package revision (PR) as bitbake tracks the package by version.
Adding Packages to Image
One very simple way to do this that may or may not work depending on the complexity and dependencies is:
- Build Yocto according to the instructions at Yocto/Building
- Add the following line to the conf/local.conf file
IMAGE_INSTALL_append = " package"
- Note package would be replaced by something such as tcpdump or openvpn, etc
IMAGE_INSTALL_append = " tcpflow tcpdump openvpn"
- Note package would be replaced by something such as tcpdump or openvpn, etc
- Recompile by using the bitbake command as explained on the Building page here:
- Look for the .ipk file in the location tmp/deploy/ipk/armv7a-vfp-neon folder.
$ find ./tmp/deploy/ipk -name "*openvpn*.ipk" ./tmp/deploy/ipk/armv7a-vfp-neon/openvpn_2.1.3-r0_armv7a-vfp-neon.ipk ./tmp/deploy/ipk/armv7a-vfp-neon/openvpn-dev_2.1.3-r0_armv7a-vfp-neon.ipk ./tmp/deploy/ipk/armv7a-vfp-neon/openvpn-doc_2.1.3-r0_armv7a-vfp-neon.ipk ./tmp/deploy/ipk/armv7a-vfp-neon/openvpn-dbg_2.1.3-r0_armv7a-vfp-neon.ipk
- There are a few ipk files, however they are for dev, doc, and dbg (debug). For main purposes, use the main one (eg openvpn_2.1.3-r0_armv7a-vfp-neon.ipk)
- Place this file onto the Ventana board through a method such as wget. Then install using the opkg install command
root@ventana:/tmp# wget http://192.168.1.22/ipk/openvpn_2.1.3-r0_armv7a-vfp-neon.ipk --2014-02-19 04:27:59-- http://192.168.1.22/ipk/openvpn_2.1.3-r0_armv7a-vfp-neon.ipk Connecting to 192.168.1.22:80... connected. HTTP request sent, awaiting response... 200 OK Length: 208174 (203K) Saving to: 'openvpn_2.1.3-r0_armv7a-vfp-neon.ipk' 100%[======================================>] 208,174 --.-K/s in 0.02s 2014-02-19 04:27:59 (12.9 MB/s) - 'openvpn_2.1.3-r0_armv7a-vfp-neon.ipk' saved [208174/208174] root@ventana:/tmp# opkg install openvpn_2.1.3-r0_armv7a-vfp-neon.ipk Installing openvpn (2.1.3-r0) to root... openvpn: unsatisfied recommendation for kernel-module-tun Configuring openvpn. root@ventana:/tmp#
Modifying Packages through BB configuration File
Here is an example.
Let's use the gst-plugins-bad package as an example. This package has quite a few items inside of it. This will all be controlled in it's bb file.
Location: sources/poky/meta/recipes-multimedia/gstreamer/gst-plugins-bad_0.10.23.bb
Open this file, and modify it. In this example, we want to be sure that the mpegtsdemux is built and added, so inside the file, we add mpegtsdemux into the EXTRA_OECONF variable under the --with-plugins flag
EXTRA_OECONF += "--disable-examples --disable-experimental --disable-sdl --disable-cdaudio --disable-directfb \
--with-plugins=musicbrainz,wavpack,ivorbis,mpegvideoparse,mpegtsdemux --disable-vdpau --disable-apexsink \
--disable-orc"
After modifying the file, save it.
Then, build the package individually like in the examples above on this page:
bitbake gst-plugins-bad
The artifacts will be in the usual location:
./build/tmp/deploy/ipk/armv7a-vfp-neon/gst-plugins-bad-mpegtsdemux_0.10.23-r2_armv7a-vfp-neon.ipk
Kernel Configuration
Bitbake Menu Config
You can modify the kernel configuration using the 'menuconfig' task. For example:
bitbake -c menuconfig linux-imx
Then, navigate through the menu and enable or disable the desired items.
Once done and saved, this stores a modified config file in the kernel's work-dir (it will not be persistent if you clean or remove the workdir).
See the yocto documentation for more info
References
Please consult the Yocto project website for more information regarding their OS.
