To build the kernel you will need the actual kernel sources.

root# emerge gentoo-sources
        

Point /usr/src/linux to the correct kernel sources:

root# cd /usr/src
root# rm linux
root# ln -s linux-2.6.17-gentoo-r7 linux
        

Now we want to pick which pieces of the kernel we want, and which parts we don't want. The following command will open up a very simple but somewhat graphical interface that lets you pick which elements you want to include/exclude from your kernel. You also have the option to load some things as "Modules" that can loaded dynamically using insmod or modprobe:

root# cd /usr/src/linux
root# make menuconfig
        

Tip

You can find most of the hardware information you'll need by using lspci.

If you are using SCSI but aren't sure which modules you need here are some commands that might help:

1. root# dmesg | grep SCSI
2. root# lsmod | grep SCSI

Here are some of the features that you will need if your running Gentoo like all the cool kids do. It's helpfull to remember that options will be marked (*) when they are compiled directly into the kernel, and (M) when it's to be compiled as a kernel module (and then loaded at a later time)

Processor Type and Features -->
    Processor Family -->
        *pick your processor, and hit the spacebar
Device Drivers -->
    ATA/ATAPI/MFM/RLL support -->
        [*] VIA82CXXX chipset support #dmesg | grep IDE to see what you need
    SCSI device support -->
        SCSI low-level drivers ->
            #Remove drivers you don't need
	    #Compile directly in the drivers you need [NOT AS MODULES!]
    Networking device support -->
        Ethernet (10 or 100Mbit) -->
            #Remove drivers you don't need
            #Compile AS MODULES, the drivers you need
        Ethernet (1000Mbit) -->
            #Add drivers as needed AS MODULES
    Sound -->
        Advanced Linux Sound Architecture -->
	    #Uncheck Advanced Linux Sound Architecture if you don't need sound
	    #Add drivers AS MODULES if you need them
File systems -->
    ( ) Deselect EXT3
    (*) Reiserfs support
        

Once your finished making your selections you can close the menuconfig interface and it will ask you to save the file. Go ahead and do this, saving the file under the name /usr/src/linux/.config

Now it's time to actually compile the kernel

root# make && make modules_install
        

In order to boot from your new kernel, it must be on the boot partition

root# cp arch/i386/boot/bzImage /boot/kernel-2.6.17-gentoo-r7
        

root# cp System.map /boot/System.map-2.6.17-gentoo-r7
        

root# cd /boot
root# rm System.map
root# ln -s System.map-2.6.17-gentoo-r7 System.map
        

root# nano -w /boot/grub/grub.conf

# Make file look like this:
default 0
timeout 30
title=Gentoo Linux 2.6.17
root (hd0,0)
kernel /kernel-2.6.17-gentoo-r7 root=/dev/hda3
	

root# nano -w /etc/fstab

# Make file look like this:
/dev/hda1           /boot           ext2            defaults,noatime    1 2
/dev/hda3           /               reiserfs        noatime,notail      0 1
/dev/hda2           none            swap            sw                  0 0
/dev/cdroms/cdrom0  /mnt/cdrom      auto            noauto,ro,user      0 0
none                /proc           proc            defaults            0 0
none                /dev/shm        tmpfs           defaults            0 0
	

root# cat /proc/mounts > /etc/mtab
root# grub-install /dev/hda
    	

Tip

If you have problems with grub hanging as it tries to probe devices, you should know that grub-install gets all confused if you don't have a floppy. If you find yourself in this situation, try:

root# grub-install --recheck --no-floppy /dev/hda

If you are currently following the Gentoo install howto, you can go back resume by clicking here.

If your an alsa user (which is a good idea) you'll want to make sure you have the needed alsa utilities

user# sudo emerge -a alsa-utils alsa-driver
        

After installing a new kernel of any version, it is important that you have the appropriate /etc/modules.autoload.d/kernel-X.Y created (X.Y is the first 2 parts of your new kernel version)

For example, this kernel will require:
/etc/modules.autoload.d/kernel-2.6

If all goes well, your machine will startup with a shiney new 2.6 kernel. Enjoy!