Cool, didn't know that! It's basically a degenerate pooled memory allocator. That one is a bit more clever in that it falls through to a proper malloc when it runs out of space. That's assuming, of course, that you have a proper malloc to fall through too.

Mine will eventually wrap around and clobber whatever's at 0x0. It assumes you have a very liberal page allocator in the background to handle page faults for whatever addresses you decide to point to and automatically wire them up to RAM.