Specifications

1.2 Related Documentation
For a while now, the kernel source has come with the file
linux/Documentation/kernel−parameters.txt. This file contains a brief listing of all the boot
time arguments that you can provide, along with quick pointers to where in the source you can find where the
arguments are parsed. The idea is that this file gives developers a quick and easy place to add in a brief
description of any new arguments that they add while working on the source. As such, it will probably always
be more up to date than this document. Actually, I'm considering discontinuing this document in light of the
existence of kernel−parameters.txt. (Opinions?)
The linux directory is usually found in /usr/src/ for most distributions. All references in this document
to files that come with the kernel will have their pathname abbreviated to start with linux − you will have to
add the /usr/src/ or whatever is appropriate for your system. Some distributions may not install the full
kernel source by default, and only put in the linux/include directory. If you can't find the file in
question, then install the kernel source and/or make use of the find and locate commands. If you can't
find the kernel source package in your distribution then the kernel source is available at:
Kernel Source Home
The next best thing to reading the kernel C source itself, will be any of the other documentation files that are
distributed with the kernel itself. There are now quite a few of these, and most of them can be found in the
directory linux/Documentation and subdirectories from there. Sometimes there will be README.foo
files that can be found in the related driver directory (e.g. linux/drivers/???/, where examples of ???
could be scsi, char, or net). The general trend is to move these files into the Documentation directory, so
if a file mentioned in this document is no longer there, chances are it has been moved.
If you have figured out what boot−args you intend to use, and now want to know how to get that information
to the kernel, then look at the documentation that comes with the software that you use to boot the kernel (e.g.
LILO or loadlin). A brief overview is given below, but it is no substitute for the documentation that comes
with the booting software.
1.3 New Versions of this Document
New versions of this document can be retrieved via anonymous FTP from most Linux FTP sites in the
directory /pub/Linux/docs/HOWTO/. Updates will be made as new information and/or drivers becomes
available. If this copy that you are presently reading is more than six months old, then you should probably
check to see if a newer copy exists. I would recommend viewing this via a WWW browser or in the
Postscript/dvi format. Both of these contain cross−references that are lost in a simple plain text version.
If you want to get the official copy, here is URL.
BootPrompt−HOWTO
2. Overview of Boot Prompt Arguments
This section gives some examples of software that can be used to pass kernel boot−time arguments to the
kernel itself. It also gives you an idea of how the arguments are processed, what limitations there are on the
boot args, and how they filter down to each appropriate device that they are intended for.
The Linux BootPrompt−HowTo
1.2 Related Documentation 4