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collapseos/kernel/blockdev_cmds.asm

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NASM
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blockdev: make "seek" print out its resulting position Also, extract commands into blockdev_cmds to avoid making blockdev dependent on stdio.
2019-04-23 12:54:23 +10:00
; *** 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.
2019-05-11 08:20:43 +10:00
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.
2019-04-23 12:54:23 +10:00
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.
2019-05-11 08:20:43 +10:00
pop de
blockdev: make "seek" print out its resulting position Also, extract commands into blockdev_cmds to avoid making blockdev dependent on stdio.
2019-04-23 12:54:23 +10:00
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