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Documentation for the grub.cfg file

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pwzhangzz
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Documentation for the grub.cfg file

#1 Post by pwzhangzz »

Many of the components in the grub.cfg file are not explained. Where can I find the explanations?

OS: Sid and Bullseye

p.H
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Re: Documentation for the grub.cfg file

#2 Post by p.H »


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Re: Documentation for the grub.cfg file

#3 Post by pwzhangzz »

pwzhangzz wrote: 2022-11-07 10:12 Many of the components in the grub.cfg file are not explained.
For example, in the installed version of Sid,

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linux /boot/vmlinuz-5.10.0-14-amd64 root=UUID=19827f6b-f130-4776-a0e7-70bf25bd1ed2 ro quiet splash
The word "splash" (splash screen) was never explained in the official GRUG manuals, although we all know what is means.

In the hybrid iso (of Bullseye),

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linux  /live/vmlinuz-5.10.0-18-amd64 boot=live components splash quiet "${loopback}"
I couldn't find documentation as to whether the kernel parameter "live" refers to an instruction to boot from a live usb (which would have seemed to be redundant as evidenced by the subsequent loopback boot parameter), or it refers to the "live" directory of the root partition (where the filesystem.squashfs is located)? ? ?

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Re: Documentation for the grub.cfg file

#4 Post by p.H »

Most kernel command-line parameters are meaningless to GRUB (vga= is an exception), they are just arbitrary strings.
They may be interpreted by the kernel, kernel modules, the initramfs or any userspace program.

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Re: Documentation for the grub.cfg file

#5 Post by pwzhangzz »

Looks like the grub.cfg file is indeed a hodgepodge of a number of configuration tools. I'm mainly interested in knowing what the word "live" means as a kernel boot parameter. This is what I have been inspired to find out:

From Debian Manpage (7):

https://manpages.debian.org/bullseye/op ... .7.en.html

https://manpages.debian.org/bullseye/li ... .7.en.html

the word "live" means both (1) as a kernel parameter to activate a live-boot system (such as a live usb), as well as (2) the /live directory in root partition which contains the filesystem.squashfs image to create an aufs-based read-writable environment to boot the system from.

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Re: Documentation for the grub.cfg file

#6 Post by p.H »

pwzhangzz wrote: 2022-11-07 14:17 I'm mainly interested in knowing what the word "live" means as a kernel boot parameter
It does not mean anything to GRUB and the kernel. I guess It is intended to the live initramfs.
Yet another XY problem. If you are interested in the live system parameters, you should open a topic with the proper subject.

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Re: Documentation for the grub.cfg file

#7 Post by abu_bua »

You can either look at the lThe Linux Kernel Documentation

or the way I prefer to install the docs (you have the documented kernel of YOUR installed kernel) :

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sudo apt install linux-doc
This will install the htmls in /usr/share/doc/linux-doc-6.0 for instance, depending on the actual version.

You can now open the doc e.g. with

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open  file:///usr/share/doc/linux-doc-6.0/html/index.html
The documentation is really good and I like it also as an hardware/software instructional book!

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