[PLUG] Anyone can still remember Grub2 insides?

[tomas.kuchta.lists at gmail.com]

Hi,

I have forgotten grub2 internals since I needed them 5 years ago - Grub
documentation is not great outside normal usage.

Can anyone give me a hand here.

I want to modify Grub2 menu in a linux installation media - under mounted
/boot/grub.cfg
The installation media does not have /etc/grub.d - so, I cannot make changes in
/etc and use chroot grub2-mkconfig to apply the change.

Editing the /boot/grub.cfg has no effect.

Thanks,
Tomas