Harmonize kernel parameters add

[eroussy]

Abstract
Two different methods are used to add new kernel parameters between Debian and Yocto. We should be able to use the same.

Current status
On Yocto:

• Ansible variable extra_kernel_parameters
• Applied by the role roles/yocto/kernel_params

On Debian:

• Ansible variable grub_append
• Applied during the role roles/debian

Detailed Description
The mechanism is the same in the two cases :

• mount /boot partition if not done
• modify grub.cfg file
• regenerate grub

A common playbook/role must be used

Benefits to SEAPATH

• Simpler for new user
• Clearer

Work to be done
Create a common role that works both on Debian and Yocto

• Make the mount and umount of /boot optional
• keep the kernel_parameters_restart variable to eventually reboot the machine once it is done
• Remove old mechanism in Debian and yocto roles
• update ABB inventory example

[eroussy]

@insatomcat @dupremathieu What do you think of this proposition ?

[insatomcat]

On debian, we change the /etc/default/grub file and call update-grub, which is a command that will generate the grub.cfg.
On Yocto, if I understand the role correctly you mount the /boot, change the grub.cfg directly and unmount the /boot.
It does not seem like yocto and debian share any logic, so I don't really see the point of a common role.