Re: UEFI multiboot control usurped with each kernel update

[John Little]

On 2018-10-17-09:38:39+0100 Barry Jackson said:
>On 09/08/18 06:10, Felix Miata wrote:
>> With 3 distro installations on one disk, each OS as a kernel update is 
>> installed
>> updates NVRAM to make its entry in the ESP partition top priority. How can I
>> stop that from happening, so that my choice of priority remains first 
>> instead of
>> me needing to remember before shutdown or reboot to run efibootmgr to put it
>> back like it was before the kernel update? I don't want to prevent the update
>> from creating a new /boot/grub/grub.cfg, only from usurping boot priority.
>
>In Mageia you can use drakboot (from MCC) and select to "not touch MBR
>or ESP" in an Advanced screen.
>This adds switches ( --bootloader-id=tmp --no-nvram) to grub2-install in
>/boot/grub2/install.sh (which is used during kernel updates) to stop the
>nvram entries being upset.

Ubuntu, and I presume other debian-derived distros, supports
--no-nvram, but it's not
enough. There's a debconf config:

grub2/update_nvram: false

but when APT gets a new version of grub, and the post install script
runs, grub-install
doesn't get the memo and still overwrites grubx64.efi in the EFI
partition, pointing
the boot directory back to where it thinks it should go.

My solution for this is make a copy of ubuntu/grubx64.efi when it has the boot
directory I want (usually to a dedicated, independent of any distro,
grub partition or
subvolume) and set an EFI boot entry that uses my copy.  Now any Ubuntu distro's
grub-install won't interfere.

-- 
Regards, John Little