Baremetal is now the default build target and therefore has its sources
at the top-level. Baremetal programs build using the phase-2 Mu toolchain
that requires a Linux kernel. This phase-2 codebase which used to be at
the top-level is now under the linux/ directory. Finally, the phase-2 toolchain,
while self-hosting, has a way to bootstrap from a C implementation, which
is now stored in linux/bootstrap. The bootstrap C implementation uses some
literate programming tools that are now in linux/bootstrap/tools.
So the whole thing has gotten inverted. Each directory should build one
artifact and include the main sources (along with standard library). Tools
used for building it are relegated to sub-directories, even though those
tools are often useful in their own right, and have had lots of interesting
programs written using them.
A couple of things have gotten dropped in this process:
- I had old ways to run on just a Linux kernel, or with a Soso kernel.
No more.
- I had some old tooling for running a single test at the cursor. I haven't
used that lately. Maybe I'll bring it back one day.
The reorg isn't done yet. Still to do:
- redo documentation everywhere. All the README files, all other markdown,
particularly vocabulary.md.
- clean up how-to-run comments at the start of programs everywhere
- rethink what to do with the html/ directory. Do we even want to keep
supporting it?
In spite of these shortcomings, all the scripts at the top-level, linux/
and linux/bootstrap are working. The names of the scripts also feel reasonable.
This is a good milestone to take stock at.
This is a hacky special case. The alternative would be more general support
for generics.
One observation: we might be able to type-check some primitives using `sig`s.
Only if they don't return anything, since primitives usually need to support
arbitrary registers. I'm not doing that yet, though. It eliminates the
possibility of writing tests for them in mu.subx, which can't see 400.mu.
But it's an alternative:
sig allocate out: (addr handle _)
sig populate out: (addr handle array _), n: int
sig populate-stream out: (addr handle stream _), n: int
sig read-from-stream s: (addr stream _T), out: (addr _T)
sig write-to-stream s: (addr stream _T), in: (addr _T)
We could write the tests in Mu. But then we're testing behavior rather
than the code generated. There are trade-offs. By performing type-checking
in mu.subx I retain the option to write both kinds of tests.
Kartik K. Agaram