collapseos/blk/811
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

11 lines
386 B
Plaintext

H@ ORG ! 0x7c00 BIN( ! ( BIOS loads boot bin at 0x7c00 )
JMP8, L1 FWR8 ( start )
ORG @ 0x25 + HERE ! ( bypass BPB )
L1 FSET ( start )
CLI, CLD, AX AX XORxx, DS AX MOVsx, ES AX MOVsx,
SS AX MOVsx, SP 0xffff MOVrI, STI,
AH 2 MOVri, DX 0 MOVrI, CH 0 MOVri, CL 2 MOVri, AL 1 MOVri,
BX 0x8000 MOVrI, 0x13 INT, ( read 2nd sector of boot floppy )
BX JMPr,
ORG @ 0x1fe + HERE ! 0x55 A, 0xaa A,