Installing an R5900 Busybox with Gentoo

The R5900 is the main processor of the PlayStation 2 and this R5900 Busybox guide is specific to Gentoo Linux.

Decide whether to build a statically linked or dynamically linked variant of Busybox. The USE flag static configures this. For a default configuration, do

emerge-mipsr5900el-unknown-linux-gnu -v sys-apps/busybox

to obtain a /usr/mipsr5900el-unknown-linux-gnu/bin/busybox R5900 executable.

The command file /usr/mipsr5900el-unknown-linux-gnu/bin/busybox now prints either

/usr/mipsr5900el-unknown-linux-gnu/bin/busybox: ELF 32-bit LSB executable,
MIPS, MIPS-III version 1 (SYSV), statically linked, for GNU/Linux 3.2.0, stripped

or

/usr/mipsr5900el-unknown-linux-gnu/bin/busybox: ELF 32-bit LSB pie executable,
MIPS, MIPS-III version 1 (SYSV), dynamically linked, interpreter /lib/ld.so.1,
for GNU/Linux 3.2.0, stripped

A simple method to provisionally override a default USE flag is to prepend it as an environment variable setting. So one can do

USE="static" emerge-mipsr5900el-unknown-linux-gnu -av sys-apps/busybox

for a statically linked executable, or

USE="-static" emerge-mipsr5900el-unknown-linux-gnu -av sys-apps/busybox

with a - prefix to static for a dynamically linked executable. If circular dependencies error resolving needs multiple USE flags, then flags can be combined inside quotas, for example: USE="static prefix-guest" To permanently configure USE flags for Busybox, create a file /usr/mipsr5900el-unknown-linux-gnu/etc/portage/package.use/busybox with for example

sys-apps/busybox static

to build a statically linked executable.