Mount the flex SSD in a linux device (or USB boot). Identify the EFI partition
sudo fdisk -l
to identify the EFI System partition which in my case was /dev/sdb12
Edit file grub.cfg
and add cros_debug
to the various options
Saved the grub.cfg
file
For meltdown/spectre add kvm-intel.vmentry_l1d_flush=always
to the kernel command line the same way you added cros_debug
to enable some software mitigations.
First make sure your machine is set to developer mode and then reboot to apply any pending updates.
Execute the following to remove the root FS verification:
sudo /usr/share/vboot/bin/make_dev_ssd.sh --remove_rootfs_verification
The command will fail with a warning and tell you to run the same command with --partitions 4
flag at the end where 4 can be any number. Run the command again with the new flag.
Then set the following variable:
sudo crossystem dev_boot_signed_only=0
Then remount your root FS with:
sudo mount -o remount,rw /
References:
https://www.reddit.com/r/ChromeOSFlex/comments/swxlz8/tutorial_enable_developer_mode_on_cros
https://www.reddit.com/r/chromeos/comments/stl9fq/enabled_developer_mode_on_chromeos_flex_by/
https://old.reddit.com/r/ChromeOSFlex/comments/w3ehw7/fixing_audio_on_bay_trail_chromebooks/