pokecrystal/home/serial.asm

Serial:: ; 6ef
; The serial interrupt.

	push af
	push bc
	push de
	push hl

	ld a, [hMobileReceive]
	and a
	jr nz, .mobile

	ld a, [wPrinterConnectionOpen]
	bit 0, a
	jr nz, .printer

	ld a, [hLinkPlayerNumber]
	inc a ; is it equal to -1?
	jr z, .init_player_number

	ld a, [rSB]
	ld [hSerialReceive], a

	ld a, [hSerialSend]
	ld [rSB], a

	ld a, [hLinkPlayerNumber]
	cp $2
	jr z, .player2

	ld a, 0 << rSC_ON
	ld [rSC], a
	ld a, 1 << rSC_ON
	ld [rSC], a
	jr .player2

.mobile
	call MobileReceive
	jr .end

.printer
	call PrinterReceive
	jr .end

.init_player_number
	ld a, [rSB]
	cp $1
	jr z, .player1
	cp $2
	jr nz, .player2

.player1
	ld [hSerialReceive], a
	ld [hLinkPlayerNumber], a
	cp $2
	jr z, ._player2

	xor a
	ld [rSB], a
	ld a, $3
	ld [rDIV], a

.wait_bit_7
	ld a, [rDIV]
	bit 7, a
	jr nz, .wait_bit_7

	ld a, 0 << rSC_ON
	ld [rSC], a
	ld a, 1 << rSC_ON
	ld [rSC], a
	jr .player2

._player2
	xor a
	ld [rSB], a

.player2
	ld a, $1
	ld [hFFCA], a
	ld a, $fe
	ld [hSerialSend], a

.end
	pop hl
	pop de
	pop bc
	pop af
	reti
; 75f

Function75f:: ; 75f
	ld a, $1
	ld [hFFCC], a
.loop
	ld a, [hl]
	ld [hSerialSend], a
	call Function78a
	push bc
	ld b, a
	inc hl
	ld a, $30
.wait
	dec a
	jr nz, .wait
	ld a, [hFFCC]
	and a
	ld a, b
	pop bc
	jr z, .load
	dec hl
	cp $fd
	jr nz, .loop
	xor a
	ld [hFFCC], a
	jr .loop

.load
	ld [de], a
	inc de
	dec bc
	ld a, b
	or c
	jr nz, .loop
	ret
; 78a

Function78a:: ; 78a
.loop
	xor a
	ld [hFFCA], a
	ld a, [hLinkPlayerNumber]
	cp $2
	jr nz, .not_player_2
	ld a, $1
	ld [rSC], a
	ld a, $81
	ld [rSC], a
.not_player_2
.loop2
	ld a, [hFFCA]
	and a
	jr nz, .reset_ffca
	ld a, [hLinkPlayerNumber]
	cp $1
	jr nz, .not_player_1_or_wLinkTimeoutFrames_zero
	call CheckwLinkTimeoutFramesNonzero
	jr z, .not_player_1_or_wLinkTimeoutFrames_zero
	call .delay_15_cycles
	push hl
	ld hl, wLinkTimeoutFrames + 1
	inc [hl]
	jr nz, .no_rollover_up
	dec hl
	inc [hl]

.no_rollover_up
	pop hl
	call CheckwLinkTimeoutFramesNonzero
	jr nz, .loop2
	jp SerialDisconnected

.not_player_1_or_wLinkTimeoutFrames_zero
	ld a, [rIE]
	and $f
	cp $8
	jr nz, .loop2
	ld a, [wcf5d]
	dec a
	ld [wcf5d], a
	jr nz, .loop2
	ld a, [wcf5d + 1]
	dec a
	ld [wcf5d + 1], a
	jr nz, .loop2
	ld a, [hLinkPlayerNumber]
	cp $1
	jr z, .reset_ffca

	ld a, 255
.delay_255_cycles
	dec a
	jr nz, .delay_255_cycles

.reset_ffca
	xor a
	ld [hFFCA], a
	ld a, [rIE]
	and $f
	sub $8
	jr nz, .rIE_not_equal_8

	ld [wcf5d], a
	ld a, $50
	ld [wcf5d + 1], a

.rIE_not_equal_8
	ld a, [hSerialReceive]
	cp $fe
	ret nz
	call CheckwLinkTimeoutFramesNonzero
	jr z, .wLinkTimeoutFrames_zero
	push hl
	ld hl, wLinkTimeoutFrames + 1
	ld a, [hl]
	dec a
	ld [hld], a
	inc a
	jr nz, .no_rollover
	dec [hl]

.no_rollover
	pop hl
	call CheckwLinkTimeoutFramesNonzero
	jr z, SerialDisconnected

.wLinkTimeoutFrames_zero
	ld a, [rIE]
	and $f
	cp $8
	ld a, $fe
	ret z
	ld a, [hl]
	ld [hSerialSend], a
	call DelayFrame
	jp .loop

.delay_15_cycles
	ld a, 15
.delay_cycles
	dec a
	jr nz, .delay_cycles
	ret
; 82b

CheckwLinkTimeoutFramesNonzero:: ; 82b
	push hl
	ld hl, wLinkTimeoutFrames
	ld a, [hli]
	or [hl]
	pop hl
	ret
; 833

SerialDisconnected:: ; 833
	dec a
	ld [wLinkTimeoutFrames], a
	ld [wLinkTimeoutFrames + 1], a
	ret
; 83b

Function83b:: ; 83b
	ld hl, wPlayerLinkAction
	ld de, wOtherPlayerLinkMode
	ld c, $2
	ld a, $1
	ld [hFFCC], a
.asm_847
	call DelayFrame
	ld a, [hl]
	ld [hSerialSend], a
	call Function78a
	ld b, a
	inc hl
	ld a, [hFFCC]
	and a
	ld a, $0
	ld [hFFCC], a
	jr nz, .asm_847
	ld a, b
	ld [de], a
	inc de
	dec c
	jr nz, .asm_847
	ret
; 862

Function862:: ; 862
	call LoadTileMapToTempTileMap
	callfar PlaceWaitingText
	call WaitLinkTransfer
	jp Call_LoadTempTileMapToTileMap
; 871


Function871:: ; 871
	call LoadTileMapToTempTileMap
	callfar PlaceWaitingText
	jp WaitLinkTransfer
; 87d

; One "giant" leap for machinekind

WaitLinkTransfer:: ; 87d
	ld a, $ff
	ld [wOtherPlayerLinkAction], a
.loop
	call LinkTransfer
	call DelayFrame
	call CheckwLinkTimeoutFramesNonzero
	jr z, .check
	push hl
	ld hl, wLinkTimeoutFrames + 1
	dec [hl]
	jr nz, .skip
	dec hl
	dec [hl]
	jr nz, .skip
	; We might be disconnected
	pop hl
	xor a
	jp SerialDisconnected

.skip
	pop hl

.check
	ld a, [wOtherPlayerLinkAction]
	inc a
	jr z, .loop

	ld b, 10
.receive
	call DelayFrame
	call LinkTransfer
	dec b
	jr nz, .receive

	ld b, 10
.acknowledge
	call DelayFrame
	call LinkDataReceived
	dec b
	jr nz, .acknowledge

	ld a, [wOtherPlayerLinkAction]
	ld [wOtherPlayerLinkMode], a
	ret
; 8c1

LinkTransfer:: ; 8c1
	push bc
	ld b, SERIAL_TIMECAPSULE
	ld a, [wLinkMode]
	cp LINK_TIMECAPSULE
	jr z, .got_high_nybble
	ld b, SERIAL_TIMECAPSULE
	jr c, .got_high_nybble
	cp LINK_TRADECENTER
	ld b, SERIAL_TRADECENTER
	jr z, .got_high_nybble
	ld b, SERIAL_BATTLE

.got_high_nybble
	call .Receive
	ld a, [wPlayerLinkAction]
	add b
	ld [hSerialSend], a
	ld a, [hLinkPlayerNumber]
	cp $2
	jr nz, .player_1
	ld a, $1
	ld [rSC], a
	ld a, $81
	ld [rSC], a

.player_1
	call .Receive
	pop bc
	ret
; 8f3

.Receive: ; 8f3
	ld a, [hSerialReceive]
	ld [wOtherPlayerLinkMode], a
	and $f0
	cp b
	ret nz
	xor a
	ld [hSerialReceive], a
	ld a, [wOtherPlayerLinkMode]
	and $f
	ld [wOtherPlayerLinkAction], a
	ret
; 908

LinkDataReceived:: ; 908
; Let the other system know that the data has been received.
	xor a
	ld [hSerialSend], a
	ld a, [hLinkPlayerNumber]
	cp $2
	ret nz
	ld a, $1
	ld [rSC], a
	ld a, $81
	ld [rSC], a
	ret
; 919

Function919:: ; 919
; XXX
	ld a, [wLinkMode]
	and a
	ret nz
	ld a, $2
	ld [rSB], a
	xor a
	ld [hSerialReceive], a
	ld a, $0
	ld [rSC], a
	ld a, $80
	ld [rSC], a
	ret
; 92e