Yocto

The Yocto Project (YP) is a popular open-source collaboration project focused on embedded Linux developers. In early versions of YP it could be problematic to get it running on Arch Linux. In later versions this is no longer the case, and hopefully in the future it will be even easier. For information about how to get it running on older version, there is a good guide here.

To use bitbake as a standalone tool, install bitbake^AUR. To edit bitbake recipes in vim, install bitbake-vim^AUR.

For this guide the focus will be on YP Core 1.8 (Fido) and newer.

Note: Arch Linux is not validated to work with Yocto/Poky.

Installation

Install the git, diffstat, unzip, texinfo, python, chrpath, wget, xterm, sdl, rpcsvc-proto, socat, cpio and inetutils packages.

Enable the multilib repository and install the multilib-devel group.

Clone the official git repository. In this example the morty branch is used.

$ git clone --branch morty git://git.yoctoproject.org/poky.git ~/poky

YP Core from Fido but before Morty

YP Core required python2, from the Python page:

$ mkdir -p ~/bin
$ ln -s /usr/bin/python2 ~/bin/python
$ ln -s /usr/bin/python2-config ~/bin/python-config
$ export PATH=~/bin:$PATH

Note: You will probably not get notified with any message if building the environment script fails because of invalid Python version.

Build core-image-minimal

Time to build the core-image-minimal target. First place yourself in the poky directory and source the environment script. Then build it with bitbake:

$ cd ~/poky
$ source oe-init-build-env build-qemux86

Tip:

In ~/poky/build-qemux86/conf/local.conf:

• Change the directory for downloads in order to reuse them, example DL_DIR ?= "~/poky-downloads".
• The build system can use a substantial amount of disk space during the build process, in order to preserve disk space add the line INHERIT += "rm_work".

$ bitbake core-image-minimal

WARNING: Host distribution "Arch-Linux" has not been validated with this version of the build system; you may possibly experience unexpected failures. It is recommended that you use a tested distribution.
Parsing recipes: 100%
|########################################################################################################################################################################################################################################################################################| Time: 00:02:42
Parsing of 884 .bb files complete (0 cached, 884 parsed). 1285 targets, 41 skipped, 0 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies

Build Configuration:
BB_VERSION        = "1.26.0"
BUILD_SYS         = "x86_64-linux"
NATIVELSBSTRING   = "Arch-Linux"
TARGET_SYS        = "i586-poky-linux"
MACHINE           = "qemux86"
DISTRO            = "poky"
DISTRO_VERSION    = "1.8"
TUNE_FEATURES     = "m32 i586"
TARGET_FPU        = ""
meta              
meta-yocto        
meta-yocto-bsp    = "fido:08d32590411568e7bf11612ac695a6e9c6df6286"

NOTE: Preparing RunQueue
NOTE: Executing SetScene Tasks
NOTE: Executing RunQueue Tasks
WARNING: Failed to fetch URL http://downloads.sourceforge.net/project/libpng/libpng16/1.6.16/libpng-1.6.16.tar.xz, attempting MIRRORS if available
NOTE: Tasks Summary: Attempted 1989 tasks of which 9 did not need to be rerun and all succeeded.

Summary: There were 2 WARNING messages shown.

This will take some time to complete. For more details about yocto there is a Quick Start Guide.

Note: The first warning about Arch Linux not been validated is expected. The second warning can happen when failing to download a resource, the build system will then attempt to get that resource from the next mirror.

Run core-image-minimal

To run this image in QEMU, start it with the runqemu command as follows:

$ runqemu qemux86

Continuing with the following parameters:
KERNEL: [/home/user/poky/build-qemux86/tmp/deploy/images/qemux86/bzImage-qemux86.bin]
ROOTFS: [/home/user/poky/build-qemux86/tmp/deploy/images/qemux86/core-image-minimal-qemux86-20150804095542.rootfs.ext4]
FSTYPE: [ext4]
Setting up tap interface under sudo
[sudo] password for user: 
Acquiring lockfile for tap0...
Running qemu-system-i386...
/home/user/poky/build-qemux86/tmp/sysroots/x86_64-linux/usr/bin/qemu-system-i386 -kernel /home/user/poky/build-qemux86/tmp/deploy/images/qemux86/bzImage-qemux86.bin -net nic,vlan=0 -net tap,vlan=0,ifname=tap0,script=no,downscript=no -cpu qemu32 -hda /home/user/poky/build-qemux86/tmp/deploy/images/qemux86/core-image-minimal-qemux86-20150804095542.rootfs.ext4 -show-cursor -usb -usbdevice wacom-tablet -vga vmware -no-reboot -m 256 --append "vga=0 uvesafb.mode_option=640x480-32 root=/dev/hda rw mem=256M ip=192.168.7.2::192.168.7.1:255.255.255.0 oprofile.timer=1 rootfstype=ext4 "
Set 'tap0' nonpersistent
Releasing lockfile of preconfigured tap device 'tap0'

Tip: If the kernel was recently updated, rebooting might help you avoid issues with tunctl.