During "make updatebootstrap", we use less than 0x20 bytes on the
PSP side and less than 0x40 bytes on the RSP one. 0x100 bytes ought
to be enough for anybody.
Use straight VARIABLE instead of Z80MEM+. Initially, I used this
system to allow z80a to be embedded in a system binary, but now
I don't think it's worth it. Compiled, z80a is 2.5k. Sure, it's a
sizeable amount of RAM, but I think that even with it in RAM, I'll
manage a bootstrap within my most constrained machine, the SMS with
8K.
Now that this section is so small, I think I can see a possibility
for cross-compiling Collapse OS entirely, which would be great
because we could get rid of the relinker.
This allows us to move words like ABORT" to xcomp-core, which is
I think the last roadblock before being able to unify all drivers
into a single xcomp layer.
DO and LOOP now only compile words from stable ABI, which make them
suitable for xcomp. This will greatly simplify driver writing and
allow us to mostly avoid the low/high divide in drivers.
LEAVE is still xcomp-incompatible though.
This make us very very tight for "<0x100" limit for literal words.
Hopefully, we won't need more stuff in that area of the binary...
Usage of "LIST" wasn't explicit enough for a complete newcomer. I
hope that with this wording, anyone can figure out how to navigate
blocks and learn the system.