diff options
| author | Astatin <[email protected]> | 2024-08-03 16:12:57 +0900 |
|---|---|---|
| committer | Astatin <astatin@redacted> | 2024-08-03 16:12:57 +0900 |
| commit | 6b0db29bfccbdce4ea4a438f2ccb921173f96afa (patch) | |
| tree | 4058c787d75e6a2ee1e7e1214abb59bb9b137464 /init.gbasm | |
Initial commit
Diffstat (limited to 'init.gbasm')
| -rw-r--r-- | init.gbasm | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/init.gbasm b/init.gbasm new file mode 100644 index 0000000..1245ce7 --- /dev/null +++ b/init.gbasm @@ -0,0 +1,52 @@ +.PADTO 0x0040 +VBlank: + CALL =VBLANK_Entrypoint + RETI + +.PADTO 0x0100 +Start: + JP =Empty_VRAM + +.PADTO 0x0104 +Nintendo_Logo: ; The Nintendo logo must be stored in bytes 0x104-133 + .DB $CE,$ED,$66,$66,$CC,$0D,$00,$0B,$03,$73,$00,$83,$00,$0C,$00,$0D + .DB $00,$08,$11,$1F,$88,$89,$00,$0E,$DC,$CC,$6E,$E6,$DD,$DD,$D9,$99 + .DB $BB,$BB,$67,$63,$6E,$0E,$EC,$CC,$DD,$DC,$99,$9F,$BB,$B9,$33,$3E + +.PADTO 0x0134 +Checksum: ; The bytes 0x134-0x14d need to add up to 0xe7 (= 0xff - 0x19) + .DB $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 + .DB $00,$00,$00,$00,$00,$00,$00,$00,$00,$e7 + +Empty_VRAM: ; (Clear screen) + LD hl, $8000 ; We set the HL register to the start of VRAM + +Empty_VRAM.loop: + XOR A + LD (HL+), a ; We set the memory pointed to by HL to 0 and increase HL + LD a, $a0 + CP h ; Until h has reached $a0 ($a0000 is the end of VRAM) + JR NZ, =Empty_VRAM.loop + + ; BG Palette + LD DE, $ff47 + LD A, $e4 + LD (DE), A + + ; OBJ0 Palette + LD DE, $ff48 + LD A, $e4 + LD (DE), A + + ; LCDC + LD DE, $ff40 + LD A, (DE) + OR $06 + LD (DE), A + + ; Interrupts + LD DE, $ffff + LD A, $01 + LD (DE), A + + JP =Entrypoint |