Commit Graph

10 Commits

Author SHA1 Message Date
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