ARM programming for Gameboy Advance

Technical Resources

GBATEK - complete documentation on the GBA and NDS

ARM Hello World Series

Hello World on the GameBoy Advance - ARM Assembly Lesson H2

Hello World on the GameBoy Advance with ARM Thumb Assembly - Lesson H4 [GBA]

ARM Platform Specific Lessons

Lesson P2 - Bitmap graphics and Palette definitions on GameBoy Advance (16 bit - 32768 colors) [GBA]

Lesson P3 - Bitmap graphics and Palette definitions on GameBoy Advance (8 bit - 256 colors) [GBA]

Lesson P5 - Joypad & Pen on the GBA / NDS ... Key reading on Risc OS [NDS] [GBA] [ROS]

Lesson P6 - Sound on the Gameboy Advance [GBA]

Lesson P8 - 16 color Tilemap on the Gameboy Advance and Nintendo DS! [GBA] [NDS]

Lesson P9 - Hardware Sprites on the Gameboy Advance and Nintendo DS! [GBA] [NDS]

ARM Simple Samples

Moving a sprite on RiscOS - Simple ARM Assembly Lesson S1

Sprite moving on the GameBoy Advance - Arm Assembly Lesson S2

Lesson S4 - Sprite moving on the GameBoy Advance (Thumb) [GBA]

Screen Display

In these tutorials we're going to use mode 4 - this effectively has 2 bitmap layers of 256 colors each, they are NOT PLANAR - they are linear bitmap format.
Note, it is not possible to write in bytes to the screen, We must write in WORDS... if we write a byte, both bytes of the word will be set the same - effectively halving the horizontal resolution

Memory Map

Sound

Port	Name	Description	Bits	Details
4000060h	SOUND1CNT_L	Channel 1 Sweep register	---------TTTDSSS	S=sweep shift D=direction T=Time
4000062h	SOUND1CNT_H	Channel 1 Duty/Length/Envelope (NR11	VVVVDSSSWWLLLLLL	L=length W=wave pattern duty S=envelope Step D= env direction V=Volume
4000064h	SOUND1CNT_X	Channel 1 Frequency/Control	IL---FFFFFFFFFFF	I=Init sound L=no loop F=Frequency
4000068h	SOUND2CNT_L	Channel 2 Duty/Length/Envelope (NR21	VVVVDSSSWWLLLLLL	L=length W=wave pattern duty S=envelope Step D= env direction V=Volume
400006Ch	SOUND2CNT_H	Channel 2 Frequency/Control	IL---FFFFFFFFFFF	I=Init sound L=no loop F=Frequency
4000070h	SOUND3CNT_L	Channel 3 Stop/Wave RAM select (NR30)	-------PBD-----	D=Dimension B=Bank P=Play
4000072h	SOUND3CNT_H	Channel 3 Length/Volume	FVV-----LLLLLLLL	L=sound Length V=volume F=Force
4000074h	SOUND3CNT_X	Channel 3 Frequency/Control	IL---FFFFFFFFFFF	I=Init sound L=no loop F=Frequency
4000078h	SOUND4CNT_L	Channel 4 Length/Envelope	VVVVDSSS--LLLLLL	L=length S=envelope Step D= env direction V=Volume
400007Ch	SOUND4CNT_H	Channel 4 Frequency/Control	IL------SSSSCRRR	R=dividing Ration, C=Counter S=shify clock freq L+no Loop I=Init sound
4000080h	SOUNDCNT_L	Control Stereo/Volume/Enable	LLLLRRRR-lll-rrr	LR=Channel on lr=master vol(7=max)
4000082h	SOUNDCNT_H	Control Mixing/DMA Control	BBBBAAAA-ba-VV
4000084h	SOUNDCNT_X	Control Sound on/off	M---4321	M=Master ON 1234 (Read) = Sound on flag
4000088h	BIOS SOUNDBIAS	Sound PWM Control	AA----BBBBBBBBB-	A=Amplitude B=Bios
4000090h	WAVE_RAM	16 Bytes	1111222233334444	4 bit sample data
40000A0h	FIFO_A	Channel A FIFO	----DDDD----DDDD	D=Wawave Data
40000A4h	FIFO_B	Channel B FIFO	----DDDD----DDDD	D=Wawave Data

Ports

Learn Assembly for the Greatest Classic Processors:  Z80 - 6502 - 68000 - 8086 - ARM