collapseos/cvm
Virgil Dupras a7dcb522c2 Make br cells 1 byte wide
The 1 byte limitation has been effective for a while now, but I
hadn't made the move yet, I wanted to see if the limitation would
cause me problems. It doesn't.

Doing this now slightly facilitates the IY->BC move in z80.

Bootstrapping: if you try to recreate the CVM binary from the
previous commit with this code, you'll have bootstrapping problems.
The first bootstrap will compile a binary with 2-bytes wide cells
but branching conditionals that yields 1-byte cells. That's bad.

I got around the issue by temporarily inserting a "397 399 LOADR"
instruction in cvm/xcomp.fs, right before the xcomp overrides. This
way, I force 1-byte cells everywhere on the first compiliation,
which then allows me to apply the logic change in cvm/vm.c and have
a properly running binary.
2020-07-06 07:27:50 -04:00
..
.gitignore
avra.sh
forth.bin Make br cells 1 byte wide 2020-07-06 07:27:50 -04:00
forth.c
Makefile
README.md
stage.c
vm.c Make br cells 1 byte wide 2020-07-06 07:27:50 -04:00
vm.h
xcomp.fs
zasm.sh

C VM

This is a C implementation of Collapse OS' native words. It allows Collapse OS to run natively on any POSIX environment.

Requirements

You need ncurses to build the forth executable. In debian-based distros, it's libncurses5-dev.

Build

Running make will yield forth and stage executables.

Usage

To play around Collapse OS, you'll want to run ./forth. Type 0 LIST for help.

The program is a curses interface with a limited, fixed size so that it can provide a AT-XY interface.

You can get a REPL by launching the program with rlwrap(1) like this:

rlwrap -e '' -m -S '> ' ./forth /dev/stdin

Problems?

If the forth executable works badly (hangs, spew garbage, etc.), it's probably because you've broken your bootstrap binary. It's easy to mistakenly break. To verify if you've done that, look at your git status. If forth.bin is modified, try resetting it and then run make clean all. Things should go better afterwards.

A modified blkfs can also break things (although even with a completely broken blkfs, you should still get to prompt), you might want to run make pack to ensure that the blkfs file is in sync with the contents of the blk/ folder.

If that doesn't work, there's also the nuclear option of git reset --hard and git clean -fxd.

If that still doesn't work, it might be because the current commit you're on is broken, but that is rather rare: the repo on Github is plugged on Travis and it checks that everything is smooth.