Commit Graph

7 Commits

Author SHA1 Message Date
Virgil Dupras
eefbf66e95 De-stabilize (br), (?br), (loop), (s)
When writing the xcomp documentation, I realized that with careful
threading and by accepting a bit of code duplication in the xcomp
toolset, I could de-stabilize a couple of words.

(n) and EXIT are a bit trickier, but I think it can be done. It
would be nice to get rid of stable wordrefs...
2020-09-19 13:54:01 -04:00
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
Virgil Dupras
f2f520cacc Extract (br), (?br) and (loop)'s code out of stable ABI zone
There is now no more actual code in stable ABI, only references.
This makes refactoring of this code much easier. For example,
changing IY to BC as the IP register.
2020-07-05 14:57:18 -04:00
Virgil Dupras
daeb3b3c69 Extract (n) code from stable ABI 2020-07-05 14:16:24 -04:00
Virgil Dupras
4a91ee5c9c Extract (s) code from stable ABI zone
Only its jump addr remains.
2020-07-05 08:54:22 -04:00
Virgil Dupras
650481f849 z80/8086: extract 2>R code from stable ABI zone
Only its jump at 0x33 remains.

I've also fixed a strange offset oddity in 8086's (n) placement.
It was off by 2, but strangely, it ran properly. Anyway, now it's
fixed.
2020-07-05 08:03:15 -04:00
Virgil Dupras
94ed01086a pcat: move drivers and xcomp to blkfs 2020-06-22 14:21:25 -04:00