fflash

go/cros-fflash

fflash is a tool to update a ChromiumOS device with a test image from gs:// (Google Cloud Storage).

Setup & Build

Dependencies:

• go 1.18 or later. Use go version to inspect the version.
• ninja. Check with ninja --version. ninja comes with depot_tools.

In-repo setup

cd ~/chromiumos/src/platform/dev/contrib/fflash
ninja -v

(Alternative) Out of source tree setup

git clone https://chromium.googlesource.com/chromiumos/platform/dev-util
cd dev-util/contrib/fflash
ninja -v

Run

1. Make sure you can ssh ${dut_host} without typing a password

2. # in the fflash directory
   bin/fflash ${dut_host}
   

   Where ${dut_host} is the ssh target.

Usage examples

bin/fflash ${dut_host}
bin/fflash ${dut_host} -R104
bin/fflash ${dut_host} -R104-14911.0.0
bin/fflash ${dut_host} --board=cherry64 -R104
bin/fflash ${dut_host} --gs=gs://chromeos-image-archive/cherry-release/R104-14911.0.0
bin/fflash --help

What fflash does

• flashes the specified image, or latest image on the device
• clobbers stateful
• disables verified boot
• clears tpm owner
• reboot the device

it does not

• ask for sudo password
• flash minios

fflash is faster than cros flash if the connection between cros flash and the DUT is slow. cros flash proxies the gs://chromeos-image-archive images for the DUT (Google Cloud -> workstation -> DUT). fflash makes the DUT download the OS images directly, by granting the DUT a restricted access token to the Chrome OS release image directory (Google Cloud -> DUT).

Development

Run unit tests

go test ./...