collapseos/blk/811

H@ ORG ! 0x7c00 BIN( ! ( BIOS loads boot bin at 0x7c00 )
JMPs, L1 FWRs ( start )
ORG @ 0x25 + HERE ! ( bypass BPB )
L1 FSET ( start )
CLI, CLD, AX 0x800 MOVxI, DS AX MOVsx, ES AX MOVsx,
SS AX MOVsx, SP 0xffff MOVxI, STI,
AH 2 MOVri, DX 0 MOVxI, CH 0 MOVri, CL 2 MOVri, AL 1 MOVri,
BX 0 MOVxI, 0x13 INT, ( read 2nd sector of boot floppy )
0x800 0 JMPf,
ORG @ 0x1fe + HERE ! 0x55 A, 0xaa A,
recipes/pcat: first steps into 8086! 2020-06-13 04:01:24 +10:00			`H@ ORG ! 0x7c00 BIN( ! ( BIOS loads boot bin at 0x7c00 )`
8086asm: tidy up a bit 2020-06-14 06:21:56 +10:00			`JMPs, L1 FWRs ( start )`
recipes/pcat: now tested on real hardware! 2020-06-14 01:47:32 +10:00			`ORG @ 0x25 + HERE ! ( bypass BPB )`
recipes/pcat: first steps into 8086! 2020-06-13 04:01:24 +10:00			`L1 FSET ( start )`
8086asm: add support for modrm 8-bit displacement 2020-06-15 20:52:47 +10:00			`CLI, CLD, AX 0x800 MOVxI, DS AX MOVsx, ES AX MOVsx,`
			`SS AX MOVsx, SP 0xffff MOVxI, STI,`
			`AH 2 MOVri, DX 0 MOVxI, CH 0 MOVri, CL 2 MOVri, AL 1 MOVri,`
			`BX 0 MOVxI, 0x13 INT, ( read 2nd sector of boot floppy )`
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. 2020-06-14 10:06:51 +10:00			`0x800 0 JMPf,`
recipes/pcat: now tested on real hardware! 2020-06-14 01:47:32 +10:00			`ORG @ 0x1fe + HERE ! 0x55 A, 0xaa A,`