# Where to get more sources of kernel configration

## fangwen

I've been reading the Gentoo Linux Handbook recently. I find that the kernel configuration part is 

short for me.

So do you have some more kernel configuration related sources or any advice for me?

I want to get a full list of kernel configuration options, but where can I get it?

----------

## avx

Well, there's documentation inside the kernel-src itself, you can select help for any item in `make menuconfig`, you could start with a kernel seed and go from there and of course, there's always Google.

What exactly is your problem? Do you have fear of the kernel not being able to boot your system? Do you want to keep it small? Do you need special features usually not used on a desktop/notebook?

----------

## aCOSwt

I have frequently relied on what I could find under the /usr/src/linux/Documentation directory.

----------

## fangwen

I do have fear of the kernel not being able to boot up. Actually I have been preparing for Gentoo installation

for about 2 weeks and I am still a little confused. 

Will the default configuration work?

----------

## m.s.w

Don't be scared. Just find out how to configure your boot manager (LILO or GRUB, whichever you use) to have an selection at boot. Then you keep your working configuratin at one position, and the second one will be your testing one where you will test your new, "hand-made" kernel.

Mine /etc/lilo.conf

```

# $Header: /var/cvsroot/gentoo-x86/sys-boot/lilo/files/lilo.conf,v 1.2 2004/07/18 04:42:04 dragonheart Exp $

# Author: Ultanium

#

# Start LILO global section

#

lba32

# If lba32 do not work, use linear:

#linear

# MBR to install LILO to:

boot = /dev/sda

map = /boot/.map

install = /boot/boot-menu.b   

menu-scheme=Wb

prompt

timeout=20

delay = 20

#

# End LILO global section

#

#

# Linux bootable partition config begins

#

image = /boot/gentoo-2.6.39

        root = /dev/sda3

        label = Gentoo

        read-only # read-only for checking

        vga=0x31B

image = /boot/previous.kernel

        root = /dev/sda3

        label = Gentoo-old

        read-only # read-only for checking

        append="vt.default_utf8=0 video=uvesafb:1280x1024-32,mtrr:2,ywrap"

# Linux bootable partition config ends

#

#

# DOS bootable partition config begins

#

#other = /dev/sdb1

        #label = Windows

        #table = /dev/sdb

#

# DOS bootable partition config ends  

#

```

Thanks to above configuration, durig boot lilo shows a menu so I can choose between:

1. Gentoo

2. Gentoo-old

If one configuration is OK (Gentoo-old), then even If I fail to build correct kernel I can alway boot into old configuration to correct the new one.

I don't know how to do it in GRUB.

You need to know how to configure LILO and GRUB before you proceed.

Best Regards,

m.s.w

----------

## avx

 *fangwen wrote:*   

> Will the default configuration work?

 If you have fairly generic hardware, the default set might boot, but it surely isn't perfect for your system.

If you never built a kernel yourself, just use genkernel (in portage) to generate one and then have a look at it and see if you're sattisfied or if you'd like to change something.

As long as it boots and supports your hardware, you've done a lot and there aren't many things to do - ie, there's no magic "50% faster" switch. You can tweak for your needs and wishes, but maybe you should run the system first to see what's really needed.

----------

## Mepho

All I ever had to use was 'h' button for help, '/' for search in menuconfig. When I wasnt sure about anything, I either used google or experimented. 

Also this page may be helpfull:

http://kmuto.jp/debian/hcl/index.rhtmlx

Just drop in output from 'lspci -n' and it will search for compat. hw and needed kernel modules (keep in mind that it only works for pci components of mobo and such, but it helps a lot though it's lil outdated and tailored towards debianees).

----------

## gerard27

I am surprised no one mentioned Pappy's kernel seeds.

http://kernel-seeds.org/

Here you can find the info you need I think.

Gerard.

----------

## avx

 *gerard82 wrote:*   

> I am surprised no one mentioned Pappy's kernel seeds.
> 
> http://kernel-seeds.org/
> 
> Here you can find the info you need I think.
> ...

 I'm surprised you think no one mentioned it, look at my first post(first reply)  :Twisted Evil: 

----------

## gerard27

Sorry avx.

Must have overlooked it.

Gerard.

----------

## avx

No problem, can't be mentioned enough  :Smile: 

----------

## ultraslinky

Keep in mind... those kernel seeds say they are "tweaked for performance". A laptop / netbook won't like those settings very much, all the power saving options are turned off.

But hey fangwen, i recommend you don't use genkernel. Use the default kernel menuconfig, it's a learning experience. And the only kernel option that is really, really crucial to booting is the hard disk section: make sure you have that compiled into the kernel and not as a module (my first kernel failed booting because of that). And read the kernel helps, they are usually very informative. 

Or then you could use genkernel for the first kernel and then do as m.s.w said.

----------

## fangwen

Thank you so much for all your help and advice.

Now I am quite confident of kernel configuration. I am not going to use genkernel because the spirit of Gentoo is choice and DIY.

First make it run, then make it run faster, right?

----------

## ultraslinky

Well yeah, that's the spirit. Of course, as avx said, there's no "magic 50% speed increase" option, most of the options in the kernel are about device support, and if they are not used they will just make your kernel larger. Maybe the biggest speed increase i have seen by modifying the kernel options is to disable kernel debugging, but of course you only do that when your system is up and running fine  :Smile: 

----------

