Yocto Project Cheatsheet

A summary of all things one might need to work with Yocto Project. One stop repository for Yocto since there are so many variables and CLIs to work with.

Commands

All hints for CLIs like bitbake, bitbake-layers, devtool etc. used within common Yocto Project development

Purpose	Command(s)
Populate Classic SDK	bitbake -c populate_sdk <IMAGE_NAME>
Populate Extensible SDK	bitbake -c populate_sdk_ext <IMAGE_NAME>
Start build from scratch	cd $BUILD_DIR && rm -Rf tmp sstate-cache
Supported HW Boards	ls sources/meta-<hardware>*/recipes*/conf/machine/*.conf
Supported Images	ls sources/meta-<hardware>*/recipes*/images/*.bb
Single PR Server instance	bitbake-prserv --host <server_ip> --port <port> --start
Find a package in a layer	cd sources && find --name "*busybox*"
Find a recipe in a layer	cd sources && find --name "*busybox*.bb*"
Search recipe	bitbake-layers show-recipes "gdb*"
Find dependency cache	devtool search <RegEx>
Dump global env & find	bitbake -e|grep -w DISTRO_FEATURES
Locate source directory	bitbake -e <recipe>|grep ^S=
Locate working directory	bitbake -e <recipe>|grep ^WORKDIR=
devshell	bitbake -c devshell <target>
devpyshell	bitbake -c devpyshell <target>
List tasks for a recipe	bitbake -c listtasks <target>
Force a build	bitbake -f <target>
Force-run a specific task	bitbake -c compile -f <target>
Current/given pkg version	bitbake --show-versions
Verbose output	bitbake -v <target>
Display debug information	bitbake -DDD <target>
Send error report	send-error-report ${LOG_DIR}/error-report/error-report_${TSTAMP}
Create a new layer	yocto-layer create <layer_name>
Add custom layer	bitbake-layers add-layer /path/to/your_meta-layer
Remove custom layer	bitbake-layers remove-layer /path/to/your_meta-layer
Find all recipe layers	bitbake-layers show-recipes
Find all clashing recipe	bitbake-layers show-overlayed
Show all bbappend files	bitbake-layers show-appends
Flatten all Layers	bitbake-layers flatten <output_dir>
Show recipe cross-depends	bitbake-layers show-cross-depends
List layer dependencies from OE Index	bitbake-layers layerindex-show-depends <layer_name>
Fetch & add layer using OE Index	bitbake-layers layerindex-fetch <layer name>

Configuration

NOTE: This section is a WIP and under consideration from the Yocto Project members for Improvements. Until Further Updated this Section will not be changed.

All variables that can be added to files like bblayers.conf or local.conf or other configuration files in Yocto.

Purpose	File	Variable(s)
Add systemd	local.conf	DISTRO_FEATURES_append = " systemd" VIRTUAL-RUNTIME_init_manager = "systemd"
Remove sysvinit	local.conf	DISTRO_FEATURES_BACKFILL_CONSIDERED = "sysvinit" VIRTUAL-RUNTIME_initscripts = ""
Add strace	local.conf	CORE_IMAGE_EXTRA_INSTALL += "strace"
root Login w/o Password	local.conf	EXTRA_IMAGE_FEATURES ?= "debug-tweaks"
Add gcc	local.conf	EXTRA_IMAGE_FEATURES ?= "tools-sdk"
Add dropbear-ssh-server	local.conf	EXTRA_IMAGE_FEATURES ?= "ssh-server-dropbear"
Add virtualization	local.conf	DISTRO_FEATURES_append = " virtualization"
Persistent Bitbake server	local.conf	BB_SERVER_TIMEOUT= "n" # n in seconds
Remove build packages	local.conf	INHERIT += "rm_work"
Exclude packages from cleaning	local.conf	RM_WORK_EXCLUDE += "recipe_name"
Avoid -dbg packages	local.conf	INHIBIT_PACKAGE_DEBUG_SPLIT = "1"
Accept FSL's EULA license	local.conf	ACCEPT_FSL_EULA = "1"
Download Directory	local.conf	DL_DIR ?= "${BSP_DIR}/downloads/"
Configuring a Pre-mirror	local.conf	INHERIT += "own-mirrors" SOURCE_MIRROR_URL = "http://example.com/source-mirror"
tarballs of git repos.	local.conf	BB_GENERATE_MIRROR_TARBALLS = "1"
Build using Pre-mirrors only	local.conf	BB_FETCH_PREMIRRORONLY = "1"
Add Package Mgmt. System	local.conf	EXTRA_IMAGE_FEATURES += "package-management"
Simple PR server	local.conf	PRSERV_HOST = "<server_ip>:<port>"
Enable build history	local.conf	INHERIT += "buildhistory"
Store build history in repo.	local.conf	BUILDHISTORY_COMMIT = "1"
Track image, pkg, SDKs change	local.conf	BUILDHISTORY_FEATURES = "image" # package or sdk
Track a file for buildhistory	local.conf	BUILDHISTORY_IMAGE_FILES += "/path/to/file"
Terminal for dev(py)shell	local.conf	OE_TERMINAL = "screen"
Submit Failed build error	local.conf	INHERIT += "report-error"
Number of parallel tasks	local.conf	BB_NUMBER_THREADS ?= "${@oe.utils.cpu_count()}"
Value of -j in make	local.conf	PARALLEL_MAKE ?= "-j ${@oe.utils.cpu_count()}"
Add Real-Time Kernel	local.conf	PREFERRED_PROVIDER_virtual/kernel = "<RT_Kernel_Image_name_from_Meta-Layer>"

Misc.

All miscellaneous resources once can find for understanding the Yocto Project and working with it.

Documentation / Websites

• repo Command Reference
• OpenEmbedded Layers Index
• OpenEmbedded Errors Index

Repositories

• yocto-research by @davisRoman
• meta-diet layer, part of Blog by Johan Thelin (@e8johan)

Blogs

• Blogs by Johan Thelin (@e8johan)
  • Yocto part I – baseline boot time
  • Yocto part II – baseline image size
  • Yocto part III – a custom meta layer
  • Yocto part IV – going on a diet
• Blog by Khem Raj (@kraj)
  • Bake 64-bit Raspberry Pi 3 images with Yocto, Openembedded

Videos

• Yocto Project YouTube Channel
• Live Coding with Yocto Project Playlist