Yocto Quick Reference

Topic Command or Configuration Description
Add a package conf/local.conf or image recipe:
IMAGE_INSTALL_append = " package1 package2"
This is the simplest way to add packages to a Yocto build.
Use your own package name in place of package1, package2. Note the leading space before the package name.
For more information, read this chapter in the Yocto Project manual: http://www.yoctoproject.org/docs/current/dev-manual/dev-manual.html#usingpoky-extend-customimage-localconf
Compile the bootloader
$ bitbake virtual/bootloader
This command will compile the bootloader.
Compile the kernel
$ bitbake virtual/kernel
This command will compile the kernel.
Customize kernel configuration
$ bitbake -c menuconfig virtual/kernel
This command will open the ncurses menuconfig interface for the target Linux kernel.
Generate a cross-toolchain
$ bitbake meta-ide-support
This command will generate a cross-toolchain that can be used outside the Yocto build environment. An environment setup script is also generated in the tmp/ directory - which can be sourced to setup the current shell for cross-compilation.
Generate an SDK
$ bitbake <recipe> -c populate_sdk
This command will create a self-extracting SDK installer, containing the cross-toolchain, for a given recipe. The SDK installer executable can be found in the tmp/deploy/sdk directory.
Host requirements https://www.yoctoproject.org/docs/current/mega-manual/mega-manual.html#required-packages-for-the-build-host Instructions to host install required packages to build the base Yocto distribution can be found at this link.
Image types conf/local.conf or machine configuration file:
IMAGE_FSTYPES = "type1 type2"

Specifies what boot image formats are created upon build completion. The base types are defined in the IMAGE_TYPES variable in poky/meta/classes/image_types.bbclass. Supported notable types include: cpio, wic, tar.bz2, ext2, ext3, ext4, jffs2, ubifs, cramfs, squashfs
Maintaining Build Quality conf/local.conf:
INHERIT += "buildhistory" 
This can be a useful tool to maintain build quality as a build changes (eg, when using a new version of a package or experimenting with new configure options). More details can be found here: https://www.yoctoproject.org/docs/current/dev-manual/dev-manual.html#maintaining-build-output-quality
Remove temporary work conf/local.conf:
INHERIT += "rm_work"
Removes package source in tmp directory after the build completes. Drastically lowers amount of host hard drive space used for a build.
Rootfs overlay Image recipe:

rfs_overlay() {
        rsync -a ${THISDIR}/rootfs/* ${WORKDIR}/rootfs

Create a rootfs/ directory in the image recipe directory.
This configuration can be used to add directories and files exactly as you want on the target RFS. Add files and directories to the created rootfs/ directory.
If your recipe is empty/does nothing other than edit the rootfs, then also add the following to the recipe to avoid a missing package error in the do_rfs step:
FILES_${PN} = ""