By default Debian using the Grub bootloader, if you want to change a few settings you can either edit the configuration files manually

There is a section in the Debian Administrators Handbook which covers Grub, and also the LILO boot loader(s).

If you are not comfortable with this then you can use a program such as grub-customizer.

apt install grub-customizer

So the first screen you see is a list of installed operating systems.

So you can fine tune which kernel or add extra parameters.

The next tab

Allows you to customize how Grub works, you can change how long the Grub menu appears for, or hide it altogether.

You can also change how grub looks

Advanced tab should only be touched if you know what you are doing, here for reference anyway.

Don't forget to save your settings, however if you exit without saving then you will lose changes. This is good if you think you may have messed something up.

#debian,#boot,#Grub,#Configuration,#grub-customizer