contiki-os/contiki — pull request #549 by g-oikonomou (2014-01-30 16:48:49+00:00)
Title: Use -Os for CC2538 builds

As discussed in #503, `-Os` was broken with one of the toolchains
recommended in the platform's README, and for that reason we were
using `-O2` by default.

This commit sets the default to `-Os` and updates the README to no
longer recommend the toolchain in question.