Chrome OS Firmware Updater Package

This folder contains resources for packaging new Chrome OS firmware updater.

Format

The package is a ZIP format file with simple UNIX shell stub as SFX (self-extracting archive) program.

The SFX stub program is sfx2.sh.

Contents

• The package file will always start with the SFX stub program.
• The packer program will put firmware images and extra tools or files into package.
• The package will contain a signing instruction file signer_config.csv with at least following columns:
  • model_name: Platform model name.
  • firmware_image: Path to the AP (host) firmware image.
  • key_id: Signing key name, usually same as the model name.
  • ec_image: Path to the Embedded Controller firmware image.
• For platforms that supports Custom Label (LOEM), the keys for each LOEM must be put in keyset folder, with a customlabel_tag as suffix (${model}-${loem}):
  • rootkey.$CLTAG: The firmware root key
  • vblock_A.$CLTAG: The vblock in A section
  • vblock_B.$CLTAG: The vblock in A section

Create initial package

Assume you have all contents ready in $PATH_TO_DIR, just do:

cp -f sfx2.sh chromeos-firmwareupdate
./chromeos-firmwareupdate --repack $PATH_TO_DIR

Update package contents

Run command:

chromeos-firmwareupdate --repack $PATH_TO_DIR

If ZIP programs are available, you may also update directly:

(cd $PATH_TO_DIR; zip PATH_TO/chromeos-firmwareupdate .)

Extract package contents

Extract to a destination folder:

chromeos-firmwareupdate --unpack $PATH_TO_DIR

The package is using ZIP format and can also be extracted using other tools:

unzip chromeos-firmwareupdate

Check contents info

For debugging, run command:

cromeos-firmwareupdate -V

For machine friendly parsing, run following command to get JSON output:

cromeos-firmwareupdate --manifest