Reorganize home header

home.asm

@@ -1,118 +1,22 @@
 INCLUDE "constants.asm"
 
 
-; The rst vectors are unused.
-SECTION "rst 00", ROM0
- rst $38
-SECTION "rst 08", ROM0
- rst $38
-SECTION "rst 10", ROM0
- rst $38
-SECTION "rst 18", ROM0
- rst $38
-SECTION "rst 20", ROM0
- rst $38
-SECTION "rst 28", ROM0
- rst $38
-SECTION "rst 30", ROM0
- rst $38
-SECTION "rst 38", ROM0
- rst $38
-
-; Hardware interrupts
-SECTION "vblank", ROM0
- jp VBlank
-SECTION "hblank", ROM0
- rst $38
-SECTION "timer", ROM0
- jp Timer
-SECTION "serial", ROM0
- jp Serial
-SECTION "joypad", ROM0
- reti
+SECTION "NULL", ROM0
+NULL::
 
+INCLUDE "home/header.asm"
 
-SECTION "Home", ROM0
-
-DisableLCD::
- xor a
- ld [rIF], a
- ld a, [rIE]
- ld b, a
- res 0, a
- ld [rIE], a
-
-.wait
- ld a, [rLY]
- cp LY_VBLANK
- jr nz, .wait
-
- ld a, [rLCDC]
- and $ff ^ rLCDC_ENABLE_MASK
- ld [rLCDC], a
- ld a, b
- ld [rIE], a
- ret
-
-EnableLCD::
- ld a, [rLCDC]
- set rLCDC_ENABLE, a
- ld [rLCDC], a
- ret
-
-ClearSprites::
- xor a
- ld hl, wOAMBuffer
- ld b, 40 * 4
-.loop
- ld [hli], a
- dec b
- jr nz, .loop
- ret
 
-HideSprites::
- ld a, 160
- ld hl, wOAMBuffer
- ld de, 4
- ld b, 40
-.loop
- ld [hl], a
- add hl, de
- dec b
- jr nz, .loop
- ret
+SECTION "High Home", ROM0
 
+INCLUDE "home/lcd.asm"
+INCLUDE "home/clear_sprites.asm"
 INCLUDE "home/copy.asm"
 
 
-SECTION "Entry", ROM0
-
- nop
- jp Start
-
-
-SECTION "Header", ROM0
-
- ; The header is generated by rgbfix.
- ; The space here is allocated to prevent code from being overwritten.
-
- ds $150 - $104
-
-
-SECTION "Main", ROM0
-
-Start::
- cp GBC
- jr z, .gbc
- xor a
- jr .ok
-.gbc
- ld a, 0
-.ok
- ld [wGBC], a
- jp Init
-
+SECTION "Home", ROM0
 
+INCLUDE "home/start.asm"
 INCLUDE "home/joypad.asm"
 INCLUDE "data/maps/map_header_pointers.asm"
 INCLUDE "home/overworld.asm"

home/clear_sprites.asm

@@ -0,0 +1,21 @@
+ClearSprites::
+ xor a
+ ld hl, wOAMBuffer
+ ld b, 40 * 4
+.loop
+ ld [hli], a
+ dec b
+ jr nz, .loop
+ ret
+
+HideSprites::
+ ld a, 160
+ ld hl, wOAMBuffer
+ ld de, 4
+ ld b, 40
+.loop
+ ld [hl], a
+ add hl, de
+ dec b
+ jr nz, .loop
+ ret

home/header.asm

@@ -0,0 +1,57 @@
+; rst vectors (unused)
+
+SECTION "rst0", ROM0[$0000]
+ rst $38
+
+SECTION "rst8", ROM0[$0008]
+ rst $38
+
+SECTION "rst10", ROM0[$0010]
+ rst $38
+
+SECTION "rst18", ROM0[$0018]
+ rst $38
+
+SECTION "rst20", ROM0[$0020]
+ rst $38
+
+SECTION "rst28", ROM0[$0028]
+ rst $38
+
+SECTION "rst30", ROM0[$0030]
+ rst $38
+
+SECTION "rst38", ROM0[$0038]
+ rst $38
+
+
+; Game Boy hardware interrupts
+
+SECTION "vblank", ROM0[$0040]
+ jp VBlank
+
+SECTION "lcd", ROM0[$0048]
+ rst $38
+
+SECTION "timer", ROM0[$0050]
+ jp Timer
+
+SECTION "serial", ROM0[$0058]
+ jp Serial
+
+SECTION "joypad", ROM0[$0060]
+ reti
+
+
+SECTION "Header", ROM0[$0100]
+
+Start::
+; Nintendo requires all Game Boy ROMs to begin with a nop ($00) and a jp ($C3)
+; to the starting address.
+ nop
+ jp _Start
+
+; The Game Boy cartridge header data is patched over by rgbfix.
+; This makes sure it doesn't get used for anything else.
+
+ ds $0150 - @, $00

home/lcd.asm

@@ -0,0 +1,25 @@
+DisableLCD::
+ xor a
+ ld [rIF], a
+ ld a, [rIE]
+ ld b, a
+ res 0, a
+ ld [rIE], a
+
+.wait
+ ld a, [rLY]
+ cp LY_VBLANK
+ jr nz, .wait
+
+ ld a, [rLCDC]
+ and $ff ^ rLCDC_ENABLE_MASK
+ ld [rLCDC], a
+ ld a, b
+ ld [rIE], a
+ ret
+
+EnableLCD::
+ ld a, [rLCDC]
+ set rLCDC_ENABLE, a
+ ld [rLCDC], a
+ ret

home/start.asm

@@ -0,0 +1,10 @@
+_Start::
+ cp GBC
+ jr z, .gbc
+ xor a
+ jr .ok
+.gbc
+ ld a, 0
+.ok
+ ld [wGBC], a
+ jp Init