Raspberry Pi Compute Module 3

sumo
yocto
raspberrypi-cm3

#1

Board description

The Compute Module 3 is a Raspberry Pi 3 in a more flexible form factor, intended for industrial application which contains 4GB eMMC with combination of the BCM2837 processor and 1GB RAM.

URL: https://www.raspberrypi.org/products/compute-module-3/

Test results

The Yocto Project releases in the table below have been tested by the Mender community. Please update it if you have tested this integration on other Yocto Project releases:

Yocto Project Build Runtime
thud (2.6) :test_works: :test_works: 1
sumo (2.5) :test_works: :test_works:

1. Disabled GRUB integration for ARM systems which is default in meta-mender/thud. U-boot is still primary integration method for this platform.

Build Means that the Yocto Project build using this Mender integration completes without errors and outputs images.
Runtime Means that Mender has been verified to work on the board. For U-Boot-based boards, the integration checklist has been verified.

Getting started

Prerequisites

  • A supported Linux distribution and dependencies installed on your workstation/laptop as described in the Yocto Mega Manual
    • NOTE. Instructions depend on which Yocto version you intend to use.
  • Google repo tool installed and in your PATH .

Setup Yocto environment

Set the Yocto Project branch you are building for:

# set to your branch, make sure it is supported (see table above)
export BRANCH="sumo"  

Create a directory for your mender-raspberrypi setup to live in and clone the
meta information.

mkdir mender-raspberrypi && cd mender-raspberrypi

Initialize repo manifest:

repo init -u https://github.com/mendersoftware/meta-mender-community \
           -m meta-mender-raspberrypi/scripts/manifest-raspberrypi.xml \
           -b ${BRANCH}

Fetch layers in manifest:

repo sync

Next, initialize the build environment:

source setup-environment raspberrypi

Building the image

You can now proceed with building an image:

MACHINE=raspberrypi-cm3 bitbake core-image-base

Replace core-image-base with your desired image target.

Using the build output

  • tmp/deploy/images/raspberrypi0-wifi/core-image-base-raspberrypi-cm3.sdimg
  • tmp/deploy/images/raspberrypi0-wifi/core-image-base-raspberrypi-cm3.mender

The disk image (with .sdimg suffix) is used to provision the device storage for devices without Mender running already. Please proceed to the official documentation on provisioning a new device for steps to do this.

On the other hand, if you already have Mender running on your device and want to deploy a rootfs update using this build, you should use the Mender Artifact files, which have .mender suffix. You can either deploy this Artifact in managed mode with the Mender server as described in Deploy to physical devices or by using the Mender client only in Standalone deployments.

Flash instructions

For flashing we need compute module io board V3 or custom hardware where module is attached.

Following setup will describe flashing sdimg to module by using Compute module IO board.

To store sdimg to eMMC we need to install usbboot tool which will mount eMMC on host computer. Tool can be fetched from usbboot. Follow instructions in Readme how to compile and install.

When installed run:

sudo ./rpiboot

Afterwards change J4 on compute module to position USB SLAVE and connect usb with host PC and power on board. After few seconds partitions of eMMC should appear. Then follow the official documentation on provisioning a new device to store sdimg to device.
When flashing is done disconnect usb from host PC and switch jumper back to BOOT ENABLE position.

References

  • The official Mender documentation explains how Mender works. This is simply a board-specific complement to the official documentation.

Known issues


#2

Hi There,
Not sure how to edit a page, but here are two issues worth mentioning:

Currently the contents of the uboot partition (mmcblk0p1) will not be updated through mender. Files under here include the DTB files, uboot and the the kernel command line parameter file cmdline.txt.

Mender upgrades the kernel successfully by including a copy on the root filesystem and directs uboot to use this. However, a copy of the kernel uImage which came with the original sdimg will be located on the uboot partition, but not used.

Hope this helps.

BR,
Donal


#3

@DonalHEmb yes that is true and valid point. I think it should be added for all RPI based board not only this one. Some discussion about that topic: https://groups.google.com/a/lists.mender.io/forum/#!msg/mender/98PMIMUp8kA/haIrX1b1CwAJ

@mirzak what is your opinion about that? Thanks.


#4

Yes, we should definitely add this information under “Known Issues”. We have a lot of resources regarding this, so mostly copy/pasting :slight_smile:

Addition information can be found here, https://github.com/mendersoftware/meta-mender/tree/master/meta-mender-raspberrypi

@DonalHEmb, everyone should be able to edit as long as you have an account. Should be an edit button at the bottom of the post. Please let me know if you can not see it.


#5

@mirzak, I’m logged in and only have like, link and bookmark icon/buttons along with a “Reply” button.


#6

@DonalHEmb, I increased your trust level. Can you see it now?


#7

@mirzak, yes I can, thank you.