pokecrystal-board/engine/init.asm
2013-08-20 03:26:37 -04:00

226 lines
2.4 KiB
NASM

Reset: ; 150
di
call CleanSoundRestart
xor a
ld [$ffde], a
call ClearPalettes
xor a
ld [rIF], a
ld a, 1 ; VBlank int
ld [rIE], a
ei
ld hl, $cfbe
set 7, [hl]
ld c, 32
call DelayFrames
jr Init
; 16e
_Start: ; 16e
cp $11
jr z, .asm_175
xor a
jr .asm_177
.asm_175
ld a, $1
.asm_177
ld [hCGB], a
ld a, $1
ld [$ffea], a
; 17d
Init: ; 17d
di
xor a
ld [rIF], a
ld [rIE], a
ld [rRP], a
ld [rSCX], a
ld [rSCY], a
ld [rSB], a
ld [rSC], a
ld [rWX], a
ld [rWY], a
ld [rBGP], a
ld [rOBP0], a
ld [rOBP1], a
ld [rTMA], a
ld [rTAC], a
ld [$d000], a
ld a, %100 ; Start timer at 4096Hz
ld [rTAC], a
.wait
ld a, [rLY]
cp 145
jr nz, .wait
xor a
ld [rLCDC], a
; Clear WRAM bank 0
ld hl, $c000
ld bc, $d000 - $c000
.asm_1b1
ld [hl], 0
inc hl
dec bc
ld a, b
or c
jr nz, .asm_1b1
ld sp, Stack - 1
; Clear HRAM
ld a, [hCGB]
push af
ld a, [$ffea]
push af
xor a
ld hl, $ff80
ld bc, $ffff - $ff80
call ByteFill
pop af
ld [$ffea], a
pop af
ld [hCGB], a
call ClearWRAM
ld a, 1
ld [rSVBK], a
call ClearVRAM
call ClearSprites
call Function270
ld a, BANK(LoadPushOAM)
rst Bankswitch
call LoadPushOAM
xor a
ld [$ffde], a
ld [hSCX], a
ld [hSCY], a
ld [rJOYP], a
ld a, $8 ; HBlank int enable
ld [rSTAT], a
ld a, $90
ld [hWY], a
ld [rWY], a
ld a, 7
ld [hWX], a
ld [rWX], a
ld a, %11100011
; LCD on
; Win tilemap 1
; Win on
; BG/Win tiledata 0
; BG Tilemap 0
; OBJ 8x8
; OBJ on
; BG on
ld [rLCDC], a
ld a, $ff
ld [$ffcb], a
callba Function9890
ld a, $9c
ld [$ffd7], a
xor a
ld [hBGMapAddress], a
callba StartClock
xor a
ld [MBC3LatchClock], a
ld [MBC3SRamEnable], a
ld a, [hCGB]
and a
jr z, .asm_22b
call Function2ff7
.asm_22b
xor a
ld [rIF], a
ld a, %1111 ; VBlank, LCDStat, Timer, Serial interrupts
ld [rIE], a
ei
call DelayFrame
ld a, $30
call Predef
call CleanSoundRestart
xor a
ld [CurMusic], a
jp GameInit
; 245
ClearVRAM: ; 245
; Wipe VRAM banks 0 and 1
ld a, 1
ld [rVBK], a
call .clear
xor a
ld [rVBK], a
.clear
ld hl, VTiles0
ld bc, $2000
xor a
call ByteFill
ret
; 25a
ClearWRAM: ; 25a
; Wipe swappable WRAM banks (1-7)
ld a, 1
.asm_25c
push af
ld [rSVBK], a
xor a
ld hl, $d000
ld bc, $1000
call ByteFill
pop af
inc a
cp 8
jr nc, .asm_25c
ret
; 270
Function270: ; 270
ld a, $0
call GetSRAMBank
ld hl, $a000
ld bc, $0020
xor a
call ByteFill
call CloseSRAM
ret
; 283