; EIDE bootstrap - chd@nktelco.net

WC	= 256.
READ	= 0040
DRQ	= 0010

CSR	= 171000
wdalt	= 014
wddata	= 020
wdcom	= 036

; post-reset drive statie is to operate on first sector of disk 0
	reset				; force a bus reset
	tst	r1			; R1 is device CSR on entry
	bne	10$			; or maybe it isn't
	mov	#CSR,r1
10$:	tstb	wdalt(r1)		; wait until not busy
	bmi	10$	
	movb	#READ,wdcom(r1)		; read first sector of disk
20$:	bitb	#DRQ,wdalt(r1)		; wait until drive has data ready
	beq	20$
	clr	r2			; primary boot loaded at 0
	mov	#WC,r3			; one sectors worth
30$:	mov	wddata(r1),(r2)+	; empty the buffer
	dec	r3
	bne	30$
	clr	pc			; jump to primary boot

	.end