collapseos/kernel/blockdev_cmds.asm

; *** REQUIREMENTS ***
; blockdev
; stdio

blkBselCmd:
	.db	"bsel", 0b001, 0, 0
	ld	a, (hl)	; argument supplied
	cp	BLOCKDEV_COUNT
	jr	nc, .error	; if selection >= device count, error
	push	de
	ld	de, BLOCKDEV_GETC
	call	blkSel
	pop	de
	xor	a
	ret
.error:
	ld	a, BLOCKDEV_ERR_OUT_OF_BOUNDS
	ret

blkSeekCmd:
	.db	"seek", 0b001, 0b011, 0b001
	; First, the mode
	ld	a, (hl)
	inc	hl
	push	af	; save mode for later
	; HL points to two bytes that contain out address. Seek expects HL
	; to directly contain that address.
	ld	a, (hl)
	ex	af, af'
	inc	hl
	ld	a, (hl)
	ld	l, a
	ex	af, af'
	ld	h, a
	pop	af	; bring mode back
	call	blkSeek
	call	blkTell
	ld	a, h
	call	printHex
	ld	a, l
	call	printHex
	call	printcrlf
	xor	a
	ret
blockdev: make "seek" print out its resulting position Also, extract commands into blockdev_cmds to avoid making blockdev dependent on stdio. 2019-04-22 22:54:23 -04:00			`; * REQUIREMENTS *`
			`; blockdev`
			`; stdio`

			`blkBselCmd:`
			`.db "bsel", 0b001, 0, 0`
			`ld a, (hl) ; argument supplied`
			`cp BLOCKDEV_COUNT`
			`jr nc, .error ; if selection >= device count, error`
zasm: use blkdev IDs as input and output This will soon allow use to seek and tell on input, which is necessary for a second pass which is necessary for forward symbol references. This require making `blkSel` a bit more flexible. Rather than having one global selected blkdev, each app can select its own, in its own memory space. 2019-05-10 18:20:43 -04:00			`push de`
			`ld de, BLOCKDEV_GETC`
blockdev: make "seek" print out its resulting position Also, extract commands into blockdev_cmds to avoid making blockdev dependent on stdio. 2019-04-22 22:54:23 -04:00			`call blkSel`
zasm: use blkdev IDs as input and output This will soon allow use to seek and tell on input, which is necessary for a second pass which is necessary for forward symbol references. This require making `blkSel` a bit more flexible. Rather than having one global selected blkdev, each app can select its own, in its own memory space. 2019-05-10 18:20:43 -04:00			`pop de`
blockdev: make "seek" print out its resulting position Also, extract commands into blockdev_cmds to avoid making blockdev dependent on stdio. 2019-04-22 22:54:23 -04:00			`xor a`
			`ret`
			`.error:`
			`ld a, BLOCKDEV_ERR_OUT_OF_BOUNDS`
			`ret`

			`blkSeekCmd:`
			`.db "seek", 0b001, 0b011, 0b001`
			`; First, the mode`
			`ld a, (hl)`
			`inc hl`
			`push af ; save mode for later`
			`; HL points to two bytes that contain out address. Seek expects HL`
			`; to directly contain that address.`
			`ld a, (hl)`
			`ex af, af'`
			`inc hl`
			`ld a, (hl)`
			`ld l, a`
			`ex af, af'`
			`ld h, a`
			`pop af ; bring mode back`
			`call blkSeek`
			`call blkTell`
			`ld a, h`
			`call printHex`
			`ld a, l`
			`call printHex`
			`call printcrlf`
			`xor a`
			`ret`