fwup meta layer

This is a Yocto meta layer for building fwup into Yocto projects.

Dependencies:

This layer depends on:

URI: https://github.com/openembedded/meta-openembedded.git layers: meta-oe branch: master

Usage

For conf/bblayers.conf you have to add

BBLAYERS ?= " \
   ...
  path_to_source/sources/meta-fwup \
  "

There are two main use cases:

One is to add IMAGE_INSTALL_append = "fwup" in conf/local.conf and run bitbake core-image-minimal to get an image with fwup support.

The second one is to add the following configuration in conf/local.conf:

# Add image_types_fwup to the system
IMAGE_CLASSES += "image_types_fwup"

# Declare that we want to make fwup images
IMAGE_FSTYPES = "fwup"

# It's mandatory to define a fwup config file format
FWUP_FILE = "sdimg-raspberrypi0-wifi.fwup"

When running bitbake core-image-minimal a .fw image will be created at tmp/deploy/image/<MACHINE NAME>/core-image-minimal-<MACHINE NAME>.rootfs.fw

Firmware authentication

fwup is able to create firmware authenticated archives. It's also possible to sign firmware archives generated by image_types_fwup image class. The following configuration can be added into local.conf configuration:

# Enable fwup sign
FWUP_SIGN_ENABLE = "1"

# Private key file location
FWUP_PRIVATE_KEY_FILE = "/data-work/yocto/work/fwup/build/fwup-key.priv"

# Public key file location
FWUP_PUBLIC_KEY_FILE = "/data-work/yocto/work/fwup/build/fwup-key.pub"

The variable FWUP_SIGN_ENABLE enables the code responsible for calling fwup command with the right parameters. Also the variables FWUP_PRIVATE_KEY_FILE and FWUP_PUBLIC_KEY_FILE have to point to the correct location of private and public key files.

One way to create a key pair is using the command fwup -g. However, others methods also exist.