update_kernel

Source code: update_kernel.py

Applies new kernel to DUT (for testing).

Description

This test helps replacing kernel on DUT.

Sometimes in early builds, we do need to update kernel on DUT for enabling extra drivers, bug fixes, or few workarounds. Sometimes we may want to enable or disable few kernel command line arguments.

Another case is to allow finalizing with a DEV signed firmware (due to last minute changes in manufacturing line and no time to wait for a signed complete release), we have to re-sign release image kernel with DEV keys (see http://go/cros-factory-fw-in-early-builds for more details).

All these leads to the demand of updating kernel on DUT, with the ability to resign or changing kernel command line, and that’s all supported by this test.

Test Procedure

This is an automated test without user interaction.

After started, the test will replace kernel on device partition by given arguments.

Dependency

• The DUT must be running Chrome OS image.

• flashrom and gooftool are needed if argument to_release is True.

• futility is needed if argument kernel_config is set.

Examples

To replace the kernel on TEST image partition and keep old kernel command line:

{
  "pytest_name": "update_kernel",
  "args": {
    "kernel_image": "/usr/local/factory/board/test_kernel.bin"
  }
}

To re-sign kernel on RELEASE image partition with DEV key:

{
  "pytest_name": "update_kernel",
  "args": {
    "to_release": true
  }
}

To change kernel command line of the kernel on TEST image partition:

{
  "pytest_name": "update_kernel",
  "args": {
    "kernel_config": "/usr/local/factory/board/test_kernel.cmdline"
  }
}

Test Arguments

Name	Type	Description
kernel_image	str, None	(optional; default: None) Full path of kernel.bin
kernel_config	str, None	(optional; default: None) Path to a file containing kernel command line.
to_release	bool	(optional; default: False) Set to True to update on release partition, otherwise update on test partition.