Kernel Options

[Karol Kwiatkowski]

bsd hack wrote:

> Hi,
>     I am working with the Kernel config file to optimize it and also to 
> improve the overall security of the system!

Hi, that's good. I'll try to give you some ideas to start inline below:

> I have the following quetions:
> (1) There are a few options that are not available in the default 
> kernel... like the IPFIREWALL options(and the like)... I basically need to 
> know all possible options I can add to the kernel config file! 

Have a look at /usr/src/sys/i386/conf/NOTES file (assuming your machine
architecture is i386, if not look in specific directory):

# cat /usr/src/sys/i386/conf/NOTES | head
#
# NOTES -- Lines that can be cut/pasted into kernel and hints configs.
#
# This file contains machine dependent kernel configuration notes.  For
# machine independent notes, look in /sys/conf/NOTES.

It points you to another file: usr/src/sys/conf/NOTES. There are options
with explanations in both files.

Also check FreeBSD Handbook:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig-config.html

> (2) I guess these options can be used to set the kernel variables 
> accessible through the sysctl command. So can I create my own options so 
> that I can set a few kernel variables as and when I build the custom 
> kernel?

Any sysctl variable can be set in /etc/sysctl.conf file which is used
before system goes to multi-user state. Many of them can be even changed
"live". Check man sysctl(8), it will also bring loader.conf(5) to your
attention.

> Thank you.
>  
> -HKR

Good luck,

Karol

-- 
Karol Kwiatkowski  <freebsd at orchid dot homeunix dot org>