rdos/boot/mbr.asm

	cpu 8086

%define seg 0
%define off 0x700

	org 0x7C00 - (seg << 4)

init:	cli
	mov ax, seg
	mov ds, ax
	mov es, ax
	mov ss, ax
	xor sp, sp
	mov ax, sp
	push ax

.retry:	mov ax, 0x0208
	mov cx, 2
	mov dh, 0
	mov bx, off

	int 0x13
	jc .retry

	jmp seg:off

	times (0x1BE - ($-$$)) db 0

	; assumes 16 heads, 63 sectors per track
	; image of 1.44 MB floppy starting on 2nd track
part1:	db 0x80
	db 1, 1, 0
	db 1
	db 0xFF, 0xFF, 0xFF
	dd 63
	dd 0xb40

	times (0x1FE - ($-$$)) db 0

	; Boot signature
sig:	dw 0xAA55
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`cpu 8086`
mbr: make use of BPB includes 2020-04-30 20:22:14 +02:00
Workstate on disk I/O rework 2021-12-16 13:27:23 +01:00			`%define seg 0`
			`%define off 0x700`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`org 0x7C00 - (seg << 4)`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00
			`init: cli`
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`mov ax, seg`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00			`mov ds, ax`
			`mov es, ax`
mbr: set up first 7 bytes of kernel PSP 2021-02-18 21:20:40 +01:00			`mov ss, ax`
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`xor sp, sp`
mbr: set up first 7 bytes of kernel PSP 2021-02-18 21:20:40 +01:00			`mov ax, sp`
			`push ax`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00
Omit printing dots from MBR 2021-02-18 20:38:42 +01:00			`.retry: mov ax, 0x0208`
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`mov cx, 2`
			`mov dh, 0`
Workstate on disk I/O rework 2021-12-16 13:27:23 +01:00			`mov bx, off`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00
			`int 0x13`
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`jc .retry`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00
Workstate on disk I/O rework 2021-12-16 13:27:23 +01:00			`jmp seg:off`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00
			`times (0x1BE - ($-$$)) db 0`

Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`; assumes 16 heads, 63 sectors per track`
			`; image of 1.44 MB floppy starting on 2nd track`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00			`part1: db 0x80`
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`db 1, 1, 0`
			`db 1`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00			`db 0xFF, 0xFF, 0xFF`
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`dd 63`
			`dd 0xb40`
Revamp MBR New features: - ES:DI (potential PnP structure) is preserved - FAT detection now works by checking for BPB values - Uses booterr procedure 2020-04-21 23:23:37 +02:00
			`times (0x1FE - ($-$$)) db 0`

			`; Boot signature`
Re-add support for booting from qemu harddisk 2021-02-18 20:00:54 +01:00			`sig: dw 0xAA55`