PXE

This page is about using Gentoo as a PXE server to boot just about any operating system or bootable tool. Please extend it with your own experience. The primary focus is to boot live images and the page can get renamed once we have a better name for it.

TFTP server

Create the TFTP root directory, where the chosen bootloader will be served from. Also make /tftproot owned by a user to not have to be root to do modifications.

root #mkdir /tftproot

root #chown user:usergroup /tftproot

Then choose a TFTP server, pick one of these:

atftp

One of the easiest TFTP servers to setup on Gentoo is net-ftp/atftp.

root #emerge --ask net-ftp/atftp

Add to default startup, and start service.

root #rc-update add atftp default

root #/etc/init.d/atftp restart

tftp-hpa

Many have good experience with net-ftp/tftp-hpa.

root #emerge --ask net-ftp/tftp-hpa

To run it temporarily, use the following command line.

root #in.tftpd -L --secure /tftproot

Bootloaders

The article about Diskless nodes contains plenty of useful information on how to setup a PXE environment.

GRUB2

For client configuration, see for example: Setup PXE boot with EFI Using Grub2 from openSUSE wiki.

Verify that sys-boot/grub was installed with GRUB_PLATFORMS efi-32, efi-64, pc

Next "install" needed grub files to /tftproot

user $grub-mknetdir --net-directory /tftproot

Netboot directory for i386-pc created. Configure your DHCP server to point to /tftproot/boot/grub/i386-pc/core.0
Netboot directory for i386-efi created. Configure your DHCP server to point to /tftproot/boot/grub/i386-efi/core.efi
Netboot directory for x86_64-efi created. Configure your DHCP server to point to /tftproot/boot/grub/x86_64-efi/core.efi

iPXE

There are a few different options to get the iPXE bootloaders.

The quickest way:

CODE Grabbing prebuilt binaries

cd /tftproot
for i in ipxe.efi snponly.efi undionly.kpxe ipxe.pxe; do wget -nc http://boot.ipxe.org/$i; done

But building from source (highly recommended from iPXE folks) is not hard, and allows for easy modifications.

Verify that some needed dependencies are installed:

root #emerge --ask --oneshot dev-vcs/git

CODE lets get going

git clone git://git.ipxe.org/ipxe.git
cd ipxe/src

# pcbios files
make -j8 bin/undionly.kpxe bin/ipxe.pxe
cp bin/undionly.kpxe bin/ipxe.pxe /tftproot/

# x86_64 efi files
make -j8 bin-x86_64-efi/snponly.efi bin-x86_64-efi/ipxe.efi
cp bin-x86_64-efi/snponly.efi bin-x86_64-efi/ipxe.efi /tftproot/

# x86_32 efi files
make -j8 bin-i386-efi/snponly.efi bin-i386-efi/ipxe.efi
cp bin-i386-efi/snponly.efi /tftproot/snponlyx32.efi
cp bin-i386-efi/ipxe.efi /tftproot/ipxex32.efi

The package sys-firmware/ipxe can be used, but needs USE flags such as efi, undi and still does not have all of the files we want.

PXELINUX

Exists as sys-boot/syslinux in portage and can be installed with

root #emerge --ask sys-boot/syslinux

Copy over needed files to our /tftproot this is only basic files for pcbios kernel boot, other files might be needed for other platforms

user $

cp /usr/share/syslinux/pxelinux.0 /tftproot

user $cp /usr/share/syslinux/ldlinux.c32 /tftproot

DHCP server

Bootable images

Gentoo installation

See Installation Alternatives - Diskless install using PXE for a guide on Gentoo.

Some projects exist to help setup such an environment

numberly/gentoo-pxe-builder with focus on Pxelinux and SSH automation for installation
NiKiZe/Gentoo-iPXE with focus on iPXE

Fedora installation

The following script creates a TFTP directory tree, downloads kernel and initrd images from a Fedora mirror and configures a netbootable instance of GRUB.

FILE ~/bin/fedora-pxe-install

#!/bin/bash -xe

# Mirror URL
mirror="http://dl.fedoraproject.org/pub/fedora/linux/"
# Releases
[ $# -eq 0 ] && releases="22 21/Server 21-Alpha/Workstation 20/Fedora" || releases="$*"
# Architecture: x86 | x86_64 | ...
architectures="x86_64 i386"
# TFTP directory path
prefix=/tftproot

test -n "$prefix"

menuentry() { cat &lt;&lt; EOF
menuentry "Install Fedora $release $arch ($state)" {
    linux /boot/$kernel repo=$repo
    initrd /boot/$initrd
}
EOF
}

check() {
    state="$1"
    repo="$mirror$state/$release/$arch/os"

    curl --silent --fail --head "$repo/" &gt;/dev/null
}

download() {
    test -e "$1" && { echo "Skipping: $1" &gt;&2; return 0; }
    echo "Downloading: $1 from $2" &gt;&2
    curl --silent --fail --output "$1" "$2"
}

grub2-mknetdir --net-directory "$prefix"
for release in $releases; do
    for arch in $architectures; do
        check releases || check development || check releases/test || { echo "# Check failed for $release $arch"; break; }

        kernel="fedora-$(echo "$release" | tr / -)-$arch-kernel"
        initrd="fedora-$(echo "$release" | tr / -)-$arch-initrd"
        pxerepo="$repo/images/pxeboot"

        download "$prefix/boot/$kernel" "$pxerepo/vmlinuz" || { echo "# Couldn't download kernel for $release $arch"; break; }
        download "$prefix/boot/$initrd" "$pxerepo/initrd.img" || { echo "# Couldn't download initrd for $release $arch"; break; }
        menuentry
    done
done | tee "$prefix/boot/grub/grub.cfg"

Adjust it to your needs and then run it without parameters.

root #fedora-pxe-install

Now you just need to configure TFTP and DHCP so that /tftproot is available to the netbooted machine and so that it requests /boot/grub/i386-pc/core.0 via TFTP.

Ubuntu installation

To install Ubuntu to a device via PXE, simply download an Ubuntu netboot image for the appropriate architecture. Note that most of the files in the release and architecture-specific directory are unnecessary, you simply need netboot.tar.gz (about 40MB).

Extract that file to an appropriate TFTP-served directory and configure your DHCP server with the filename directive to point at pxelinux.0 for the machine or subnet in question.

Note that you will also need to give the host(s) internet access as the netboot images are configured to pull packages down from the internet.