1.   Notice

The Juno software stack uses the Yocto project to build a Board Support Package (BSP) and the Poky Linux distribution. The Yocto project uses Bitbake to build the software stack.

2.   Prerequisites

These instructions assume that:

• Your host PC is running Ubuntu Linux 18.04 LTS.
• You are running the provided scripts in a bash shell environment.

The following utilities must be available on your host PC:

• chrpath
• compression library
• diffstat
• gawk
• makeinfo
• openssl headers
• pip
• repo
• yocto

To resolve these dependencies, run:

sudo apt-get update
sudo apt-get install chrpath gawk texinfo libssl-dev diffstat wget git-core unzip gcc-multilib \
build-essential socat cpio python python3 python3-pip python3-pexpect xz-utils debianutils \
iputils-ping python3-git python3-jinja2 libegl1-mesa libsdl1.2-dev pylint3 xterm git-lfs openssl \
curl libncurses-dev libz-dev python-pip repo

Note that this software has been tested with

• repo version 2.11
• python version 2.7

3.   Provided components

Within the Yocto project, each component included in the Juno software stack is specified as a bitbake recipe. The recipes specific to Juno are located at: <workspace>/layers/meta-arm.

4.   Syncing and Building software stack

Create a new folder that will be your workspace, which will henceforth be referred to as <workspace> in these instructions

mkdir <workspace>
cd <workspace>
repo init -u https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms-manifest.git -m juno-yocto.xml -b refs/tags/JUNO-2021.04.27
repo sync -j$(nproc)
export DISTRO="poky"
export MACHINE="juno"
source setup-environment
bitbake core-image-minimal

The initial clean build will be lengthy, given that all host utilities are to be built as well as the target images. This includes host executables (python, cmake, etc.) and the required toolchain(s)

Once the build is successful, all images will be placed in the <workspace>/build-poky/tmp-poky/deploy/images/juno directory.

Note that the BSP includes the Poky Linux distribution, which offers BusyBox-like utilities.

Connect Juno's serial port and USB type B port (both on the back panel) to the computer
Open a terminal emulator (e.g. minicom) on the computer
Power on the Juno board
On the terminal emulator:
Cmd> usb_on

On the host computer:
(adjust path to JUNO mount point as necessary):
rm -rf /media/username/JUNO/* # make a back-up first
tar -xf <workspace>/build-poky/tmp-poky/deploy/image/juno/firmware-image-juno.tar.gz -C /media/username/JUNO/
umount /media/username/JUNO/ # may take some time to sync

sudo dd if=<workspace>/build-poky/tmp-poky/deploy/image/juno/core-image-minimal-juno.ext4 of=/dev/sdX bs=1M
sudo eject /dev/sdX

Insert the USB stick in Juno board (bottom-right port on the back panel)

Refer Juno Getting Started documentation
https://developer.arm.com/tools-and-software/development-boards/juno-development-board

mkdir /path/to/nfsroot
cd /path/to/nfsroot
sudo tar xjf <workspace>/build-poky/tmp-poky/deploy/image/juno/core-image-minimal-juno.tar.bz2 # root is required

Set up an NFS server and export the nfsroot in /etc/exports:

/path/to/nfsroot *(rw,nohide,insecure,no_subtree_check,async,no_root_squash)

Restart the NFS server or run:

sudo exportfs -a

configure u-boot bootcmd
https://community.arm.com/developer/tools-software/oss-platforms/w/docs/542/nfs-remote-network-userspace-using-u-boot

https://community.arm.com/developer/tools-software/oss-platforms/w/docs/495/tftp-remote-network-kernel-using-u-boot

5.   AArch32 builds for Juno development board

yocto support for juno 32-bit is not supported

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