It's apparently ben a while since I updated this log. Oops.
I've been working in the project pretty much every day, but sometimes only for an hour or two.
Anyway, I've made a lot of progress. The assembler is done, and seems to work nicely. The binutils functions are done and working too.
I'm restarting work on the linker. This was stopped earlier because I got stuck and frustrated. My first attempt crashed pathetically, and the second failed with an "internal linker script syntax error".