Classic NES Series Anti-Emulation Measures - mGBA

Copy-protection (or, rather, emulator avoidance) on the GBA. I'm not entirely sure why they bothered.

to copy-protection games gba reverse-engineering software ... on 03 January 2015

Pin Eight: Game Boy Advance Software

... and some more little GBA games, with source available.

to games gba homebrew software ... on 21 November 2011

luminesweeper: the alternative to lumines for gba owners (action puzzle video game)

Tetris meets Minesweeper, for the GBA. Open source.

to games gba homebrew software ... on 21 November 2011

TONC

A good, technical GBA tutorial and reference.

to ag0700 games gba programming ... on 13 October 2011

Gameboy Advance

Assorted links to GBA flash cartridges and accessories (although the bias here is clearly towards piracy rather than homebrew).

to flash gba multiboot ... on 08 October 2011

GBA Multiboot Intelligent Cable - Ajo's web site

Multiboot using a PIC16F84. (Maybe I should use up my stock of PIC16C84s on this...)

to electronics gba microcontroller multiboot pic ... on 08 October 2011

USB to GBA

GBA multiboot using an EZ-USB device (lots of generic serial adaptors, etc.).

to ezusb gba microcontroller usb ... on 08 October 2011

PSoC Design Challenge 2002

Includes "Educating Mario", a project with full technical specs for the GBA multiboot protocol.

to electronics gba multiboot ... on 08 October 2011

Kuwanger.net: Gameboy Advance

Assorted emulators that run on the GBA.

to emulation gba retrocomputing software ... on 08 October 2011