This may not be up to date anymore. A complete GCC for AVR (and AMR) is now available as HaikuPorts recipes, which provide a more complete process, with a C library and everything. Refer to these recipes if you need to do it (even on other platforms, the recipes aren't all that hard to read and adjust)
As you may have noticed, I like to develop stuff for all kind of weird devices. For this, I usually need a C compiler, and most of the time it's gcc (not always).
gcc is a big piece of software and there are some tricks needed to build it. Also, I run the Haiku operating system, which is quite nonstandard, so additional workaround are needed.
Today I built gcc for avr. Here are notes on how to do it so I don't spent a month figuring it out next time.
#!/bin/sh # gcc compilation for gcc 4.4.5 (4.5.x needs more stuff. maybe later) # Made by PulkoMandy in 2010 # Before you start : # * Download gmp and mpfr from HaikuPorts (http://ports.haiku-files.org/wiki/Downloads) and extract to /boot # * Download gcc-core-4.4.5.tar.bz2 from gcc mirror and extract to work directory mkdir obj && cd obj # This is the output folder. So you can keep the source area clean setgcc gcc4 # We can't compile gcc4 with gcc2. ../gcc-4.4.5/configure --target=avr --enable-languages=c --prefix=/boot/common/ --with-mpfr=/boot/common/ # Tell the target, then language we want, and where to install the result. Binaries will be called avr-* so don't care about overwriting other ones. # For some obscure reason mpfr isn't detected properly, so we force the prefix. make all-gcc ; make install-gcc # This does compile only gcc, not libgcc; which failed to work for me.
There are other things to watch out : I had to remove a -lm somewhere as Haiku doesn't have a separate libmath.
Next : build a PlayStation development toolchain, including gcc MIPS target.