[SOLVED] GRUB2 change default to custom kernel

stormtracknole · 07-14-2015, 11:52 AM

I have made the switch from LILO to GRUB2 on all my Slackware boxes. Still learning all the ins and outs. I am running into an issue though when I want to change the default kernel to a custom compiled on. No matter what I do, the changes won't take. Has anyone been successful in doing so? I have tried playing around with changing GRUB_DEFAULT=saved to GRUB_DEFAULT=2 and even using the actual title, but no success. I've also tried this:

Code:

Open /etc/default/grub and ensure this line exists:

GRUB_DEFAULT=saved
Apply the change to grub.cfg by running:

grub-mkconfig -o /boot/grub/grub.cfg
Now list all possible menu entries

grep "submenu\|^\smenuentry" /boot/grub/grub.cfg | cut -d "'" -f2
Now set the desired default menu entry

grub-set-default "<submenu title>><menu entry title>"
Verify the default menu entry

grub-editenv list

Which I modified from this link. Still no luck.

Any help would be appreciated.

stormtracknole · 07-14-2015, 01:09 PM

Figured it out! For GRUB_DEFAULT, I was using:

Code:

GRUB_DEFAULT="Slackware-14.1 GNU/Linux, with Linux 3.18.18-local"

However, upon running grub-mkconfig -o /boot/grub/grub.cfg, I was instructed to use this instead:

Code:

GRUB_DEFAULT="gnulinux-advanced-e246d5eb-623e-4518-ae21-96df0820c0c3>gnulinux-3.18.18-local-advanced-e246d5eb-623e-4518-ae21-96df0820c0c3"

I'm sure this code will be different depending on the kernel version used and probably other factors. I ran the grub-mkconfig command again, and this time, the correct kernel was loaded. Marking this thread as solved. Hopefully it can be of help to others.

syg00 · 07-14-2015, 08:39 PM

Why are you using (grub) submenus ?. Probably just complicating things.
I always create a 40_custom entry with a sane menuentry.

stormtracknole · 07-15-2015, 08:11 AM

Quote:

Originally Posted by syg00

Why are you using (grub) submenus ?. Probably just complicating things.
I always create a 40_custom entry with a sane menuentry.

Thanks for the tip. Like I mentioned, I'm still learning the ins and outs of grub2. Needless to say, it's a lot more complicated than grub1.

stormtracknole · 07-15-2015, 10:45 AM

Also, would you mind sharing what your 40_custom file looks like? I'm reading up on some documentation on how to set up a custom menu. I'm using the default menu entries.