What You Will Learn

Prerequisites

Step 1: Install Host Packages

Every Yocto release documents an exact list of required host packages in its reference manual, and it does change slightly between releases, so always check the manual for the branch you are building. On a Debian/Ubuntu host, a typical starting set looks like this:

$ sudo apt update
$ sudo apt install -y gawk wget git diffstat unzip texinfo gcc build-essential 
    chrpath socat cpio python3 python3-pip python3-pexpect xz-utils debianutils 
    iputils-ping python3-git python3-jinja2 libegl1-mesa liberror-perl 
    python3-subunit zstd liblz4-tool file locales
$ sudo locale-gen en_US.UTF-8

Step 2: Clone Poky on the Current LTS Branch

Rather than cloning the default branch, always clone the codename of the release you want. At the time of writing, the current LTS release is 6.0 “Wrynose”, with 5.0 “Scarthgap” still under support as the previous LTS. Pick whichever your product’s support window calls for:

$ git clone -b wrynose git://git.yoctoproject.org/poky.git
$ cd poky

You will find everything — oe-core, BitBake, and the reference Poky configuration — inside this single poky directory.

Step 3: Set Up the Build Environment

Every new terminal session needs the environment script sourced before any bitbake command will work:

$ source oe-init-build-env

This creates and switches into a working directory named build, and drops you into it as your current directory. You can also name the directory explicitly, which is useful for keeping several targets side by side:

$ source oe-init-build-env build-ep-qemuarm64

Step 4: Configure the Target Machine

Open conf/local.conf in your build directory and set the MACHINE variable to a QEMU target. For a 64-bit ARM target:

$ sed -i 's/^MACHINE ??= "qemux86-64"/MACHINE ??= "qemuarm64"/' conf/local.conf
$ grep '^MACHINE' conf/local.conf

MACHINE ??= "qemuarm64"

It’s also worth pointing the shared caches outside your build directory the first time, so every future build directory you create reuses already-built artifacts instead of rebuilding from scratch:

DL_DIR ?= "/home/ravi/yocto-shared/downloads"
SSTATE_DIR ?= "/home/ravi/yocto-shared/sstate-cache"

Step 5: Build and Boot an Image

With the machine configured, build a minimal image. Expect the very first build to take anywhere from thirty minutes to a few hours depending on your hardware and network, since it compiles the entire toolchain and root filesystem from source:

$ bitbake core-image-minimal

Typical tail of a successful build looks like this:

NOTE: Tasks Summary: Attempted 3842 tasks of which 0 didn't need to be rerun
      and all succeeded.
Summary: There was 1 WARNING message.

Boot the resulting image straight in QEMU:

$ runqemu qemuarm64 nographic

Poky (Yocto Project Reference Distro) 6.0 ep-qemuarm64 ttyAMA0
ep-qemuarm64 login: root

Common Mistakes

Best Practices

Summary and Key Takeaways

Frequently Asked Questions