I often get asked to recommend a distribution for the NSLU2. Here is
some objective information on each of the five different firmware
distributions created or supported by the NSLU2-Linux project. In the
end, it usually comes down to which applications you want to run, or
which hardware you want to connect. It's not one-size-fits-all.


Unslung (through the installation of Optware packages) has about 1000
packages to choose from, each of which has been specifically compiled
for the NSLU2's unique blend of capabilities. Unslung is available in
big-endian mode only, and has a very old 2.4 kernel and a very old
version of glibc, so support for hardware accessories is hit and miss,
and there is nothing you can do to fix it if it doesn't work. Unslung
has a web user interface. There is a tiny amount of room left in
internal flash after installation, but Unslung is meant to be run from
an external storage device. If the external device fails, Unslung falls
back to running from internal flash.

SlugOS has about 5000 packages to choose from - 4000 from OpenEmbedded,
which have been specifically compiled mainly for handheld, limited
memory devices, and 1000 from Optware (as per Unslung). SlugOS is
available in either big-endian or little-endian modes, and uses a
2.6.21.7 kernel and a recent version of glibc. SlugOS does not have a
web user interface. There is a small amount of room left in internal
flash after installation (enough to run some small server applications),
but installation of large packages will require an external storage
device. If the external device fails, SlugOS falls back to running from
internal flash.

Angstrom has the same 4000 OpenEmbedded packages, but is built using the
EABI version of the ARM application binary interface, and therefore has
much better floating point performance than any other distro for the
slug. Angstrom is available in either big-endian or little-endian
modes, and uses a 2.6.21.7 kernel and a recent version of glibc.
Angstrom does not have a web user interface as such, but some packages
are available that provide web interfaces to some applications. There
is a small amount of room left in internal flash after installation
(enough to run some small server applications), but installation of
large packages will require an external storage device. If the external
device fails, then either a reflash or a serial console is currently
required for recovery.

Debian has well over 10000 packages, but they have been compiled for
desktop systems, and are therefore not optimised for the small-memory
NSLU2. Debian is available in little-endian mode only, and uses a
2.6.18 kernel and a recent version of glibc. Debian has some packages
that provide web-based interfaces. Debian can only run from an external
storage device (which means that there is no recovery ability other than
a reflash if that external device stops working).

OpenWrt has just under 2000 packages to choose from - about 1000 from
Optware, and about 1000 from OpenWrt. OpenWrt is available in
big-endian mode only, and uses a 2.6.21.6 kernel and uClibc. If you
want to do wireless or sophisticated routing, then you can't go past
OpenWrt. It is also the only 2.6 kernel distro for the slug which has a
web user interface (X-Wrt) included in the installation image. OpenWrt
has a significant amount of internal flash left after installation
(since uClibc uses so much less space than glibc), so it is very good
for disk-less applications. You can also run it from an external
storage device if you choose. If the external device fails, then either
a reflash or a serial console is currently required for recovery.


-- Rod Whitby
-- NSLU2-Linux Project Lead