Gentoo is a Linux distribution which excels at flexibility and recommends itself for easy customization. These qualities make it especially well-suited for scientific computing or for dedicated systems. The Raspberry Pi is one of the most popular (though not the only - see Cubieboard as an alternate example) single-board computers to date, and is often deployed for dedicated tasks: scientific computing, home automation, etc.

Installing Gentoo on a dedicated platform makes it easy for the user to strip down his system to suit his needs precisely - e.g. in the guise of an ultra-minimalist installation. Here we provide an overview of current means of installing Gentoo on your Raspberry Pi.

Stage 3 - without cross-compiling

This is standard “quick” way of installing Gentoo on the Raspberry Pi. It is widely recommended and features its own Gentoo Wiki guide, mainly because it is consistent with common ways of deploying Gentoo, and more-or-less conveniently circumvents the need for cross-compiling. Sadly, this approach leads to a number of drawbacks, mainly revolving around the fact that it necessitates compiling everything with the limited resources of the Raspberry Pi.

Strengths:

• Flexible (you can tailor your system from the very start, but you have to use the default kernel to start with)
• Widely used (you are very likely to get good support)

Weaknesses:

• Time consuming once you start working on the Pi.
• Requires copying a a number of sources via USB (dhcpcd, connman, etc.) before you can connect to the internet, and download everything else.

Stage 3 - with cross-compiling

This installation method allows you to unload all compilation work for the Raspberry Pi to the machine from which you are installing. As your desktop machine will have a different architecture than the Raspberry Pi, this requires cross-compiling. There are a number of Gentoo tools which help you set up cross-compilation toolchains - and some of them are covered specifically for our use case by unofficial blogs.

A few guides for a Raspberry Pi cross-compile installation with: crossdev, static QEMU, QEMU. Please note that static QEMU will not work if your system uses systemd (last checked May 2014); and crossdev-toolchains are known for being prone to compilation errors.

Strengths:

• Very Flexible (you can tailor your system from the very start, and start off with a custom kernel)
• Used by some (you are likely to get some support from people who maintain the aforementioned guide)

Weaknesses:

• Time consuming until you set up cross-compilation (which, depending on your level of computer literacy, could be a very difficult process).
• Susceptible to failed compilation for certain packages.
• May need some debugging expenditure along the way

Stage 4

Stage 4 tarballs, are bootable fully working Gentoo systems. Installing them is as easy as extracting the archive to a partitioned disk, and as they ship with more software than stage 3 tarballs, generally they reduce the time needed for subsequent compilation on the Raspberry Pi. There are no official stage 4 tarballs for the Raspberry Pi; this owes to the fact that in setting up a stage 4 tarball, the developer invariably makes a few choices for the end-user. These changes are easily undone, but this is not considered the Gentoo way of doing things.

We have a detailed guide for this simple Gentoo installation, and the stage 4 tarballs are available for download, here (one archive for the boot partition, one for the system partition). We strive to update the tarball once every 3 months, and we last updated May 2014. There are a few other Gentoo stage 4 tarballs for the Raspberry Pi available for download, e.g. one by intelminer (tarball unmaintained as of July 2012).

Strengths:

• Used by us (you are likely to get support right here in the comments section)
• Fast (you can start using your system immediately after you extract the archives)

Weaknesses:

• Less Flexible (you may have to delete software which you do not need)

NOOBS

NOOBS is the standard operating system install manager for the Raspberry Pi. It provides you with a series of installation options, and while Gentoo is not supported by default, you can dd a Gentoo image to the NOOBS OS folder (/os/Gentoo). Note that while the linked image is updated daily , the DD image is unmaintained as of May 2013.

In principle, however, this is the same as doing a stage 4 installation (see above), with the added overhead of the NOOBS install manager. Overall we do not recommend this.