Fully featured kernel debugging after a crash has happened, aka ramoops on steroids.
The kdump feature is controlled by the kdump USE flag. This is currently enabled only on dev/test images of amd64 boards.
To enable kdump on a supported device, run the following command to change the kernel booot cmdline parameters and reboot to make it take effect:
/usr/share/vboot/bin/make_dev_ssd.sh --partitions 2 --enable_kdump
After a kernel crash, the generated dump files can be found in /var/spool/kcrash.
Kdump functionality is mainly provided by the following packages:
sys-kernel/chromeos-kernel-kdump-5_15: The kdump kernel image.sys-boot/kdump-ramfs: The initramfs for the kdump kernel. It executes makedumpfile to generate the crash dump. Note that the artifacts of this package are only bundled into kdump kernel image, not the main device image.sys-apps/kexec-lite: A simple kexec-tools implementation to load the kdump kernel.sys-boot/kdump-init: The script that runs kexec-lite to load the kdump kernel.sys-apps/kdump-dev: The script that collects the dump files generated by kdump-ramfs and saves them to /var/spool/kcrash.