Re: Is GRUB2 customizeable enough?

[Simon Hobson]

Andrei Borzenkov <address@hidden> wrote:

> On Mon, Jul 25, 2016 at 12:01 PM, Simon Hobson <address@hidden> wrote:
>> Slightly modify the files in (rom memory) /etc/grub that build grub.cfg. 
>> Arrange for your primary "safe" OS to have a distinct label, then set that 
>> label as the default OS.
> 
> If we are speaking about grub2, you should use menu entry ID, not
> titles, and make sure to generate unique ID using e.g. uuidgen. Like
> 
> srv:~ # uuidgen
> 6927bd1a-8755-4cc4-8335-78f68075fcd4
> 
> and in grub.cfg
> 
> set default=6927bd1a-8755-4cc4-8335-78f68075fcd4
> ...
> menuentry "My default entry" --id 6927bd1a-8755-4cc4-8335-78f68075fcd4 {
> ...
> }


Ah, another feature I'd never heard of. I do recall in the past the advice 
handed out here (as an alternative to renaming the files in /etc/grub to get 
Xen to boot by default for example) was to specify the default option to be 
selected in /etc/default/grub (Debian system). So for example, I have in my 
defaults file :
GRUB_DEFAULT="Xen 4.0-i386>Debian GNU/Linux, with Xen 4.0-i386 and Linux 
3.2.0-4-686-pae"
(which ends up as "set default= ..." in grub.cfg)

If you are now saying there's another alternative, that's of interest.
For the OP, he'll need to know how to specify that to the OS tools so that 
update-grub[2] will handle it correctly.