From f6038a3d52a2d26271fdcba9639284301305d751 Mon Sep 17 00:00:00 2001
From: yenatch <yenatch@gmail.com>
Date: Sun, 25 May 2014 19:23:12 -0700
Subject: Try to clean up PrepareOAMData.

---
 engine/oam_dma.asm | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 engine/oam_dma.asm

(limited to 'engine/oam_dma.asm')

diff --git a/engine/oam_dma.asm b/engine/oam_dma.asm
new file mode 100644
index 00000000..6421a1b8
--- /dev/null
+++ b/engine/oam_dma.asm
@@ -0,0 +1,25 @@
+WriteDMACodeToHRAM:
+; Since no other memory is available during OAM DMA,
+; DMARoutine is copied to HRAM and executed there.
+	ld c, $ff80 % $100
+	ld b, DMARoutineEnd - DMARoutine
+	ld hl, DMARoutine
+.copy
+	ld a, [hli]
+	ld [$ff00+c], a
+	inc c
+	dec b
+	jr nz, .copy
+	ret
+
+DMARoutine:
+	; initiate DMA
+	ld a, $c3
+	ld [$ff46], a
+
+	; wait for DMA to finish
+	ld a, $28
+.wait	dec a
+	jr nz, .wait
+	ret
+DMARoutineEnd:
-- 
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