18 Commits

Author	SHA1	Message	Date
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	5ebdf84e78	pcat: more native words ... almost there!	2020-06-19 07:26:33 -04:00
Virgil Dupras	3b21ba635d	pcat: add PICK and (roll)	2020-06-18 21:21:46 -04:00
Virgil Dupras	a92864a595	pcat: implement RSP mechanism in execution model	2020-06-16 20:41:53 -04:00
Virgil Dupras	8c452f5add	pcat: begin implementing find ... Not comparing strings yet. Without asm tooling support, it's a big chunk to swallow at once. It's progressing well!	2020-06-14 21:52:58 -04:00
Virgil Dupras	3be30e24bb	pcat: implement execute and nativeWord	2020-06-14 15:27:26 -04:00
Virgil Dupras	bf0e999f8e	pcat: read LATEST and jump to it	2020-06-14 14:51:32 -04:00
Virgil Dupras	a72322df31	pcat: begin structuring around words	2020-06-14 14:15:44 -04:00
Virgil Dupras	1a467efae1	pcat: use a far jump to boot into the OS ... Unless I misunderstood, this is supposed to set CS. This would make all SREG have the same value. This allows us to remove BIN( offset from os.bin. I've tried booting to offset 0, but it didn't seem to work. Let's settle for 0x8000. 512kb of system RAM is way more than we need anyways.	2020-06-13 20:06:51 -04:00
Virgil Dupras	507c2c12e7	8086asm: clarify operands and fix stupidities	2020-06-13 17:58:42 -04:00
Virgil Dupras	5033f17be2	8086asm: tidy up a bit	2020-06-13 16:21:56 -04:00
Virgil Dupras	07e50313c7	pcat: separate MBR code and OS code ... MBR code now strictly loads OS code into memory and jumps into it. Now, I've got to consolidate my assembler code, modrm logic is messed up.	2020-06-13 15:35:16 -04:00
Virgil Dupras	b037c86598	recipes/pcat: now tested on real hardware!	2020-06-13 11:47:32 -04:00
Virgil Dupras	66b27b0790	8086asm: properly initialize DS and DF	2020-06-12 19:07:23 -04:00
Virgil Dupras	4e18fafe46	8086asm: now enough tooling to assemble a PC/AT Hello World boot	2020-06-12 13:12:41 -04:00
Virgil Dupras	210b833c71	8086asm: begin adding MODRM-enabled ops	2020-06-12 12:07:48 -04:00
Virgil Dupras	749fdf1b18	8086asm: add 8-bit JMP, MOVrI, INT, ... Verified against nasm with equivalent code.	2020-06-12 11:29:00 -04:00
Virgil Dupras	405444d630	8086asm: first steps	2020-06-12 10:49:27 -04:00