I'm really addicted to Boost Build. So when I started getting back into Dreamcast programming I worried that I'd need to create Makefiles in parallel with Jamfiles.
However, it turns out teaching Boost Build to use a new variant of GCC is ridiculously easy! You just need to edit site-config.jam and give it the path to the new compiler. However, there's some extra complications if you're building a Windows project on the Dreamcast, since Boost Build will add flags and do things that only make sense for Windows libraries. In order to get around that, I had to make a Python script that would weed out the extra arguments and call the KOS GCC compiler without them.
In the end I was able to get to where I could cross-compile functioning bjam files that worked in Windows on the Dreamcast by simply adding “–toolset=gcc-dreamcast” to the command line.
If you'd like to use Boost Build too, I've put the results of my work up on GitHub, along with instructions on how to get started.
Notice that this enables all the C++11 features supported so far by the GNU compiler, which means “auto” can now be used in a Dreamcast program. Pretty cool, right?