Things You'll Need
Instructions
Download gpSP (see resources) and save it to your desktop. Connect your PSP to your computer using a USB cord. Plug the bigger end of the USB cord into your computer and the smaller end of the cord into the top of your PSP. Navigate through the folder you just downloaded until you find the gpSP folder. Copy that folder to your PSP "Game" folder.
Download the GBA BIOS (see resources) and rename it to "gba_bios.bin." Drag that file into the gpSP folder on your PSP.
Put any Game Boy Advanced roms you have into that Game Boy Advanced folder. Unplug your PSP from your computer and restart your PSP. Scroll over to games and down to your memory card. Find gpSP on the list and start it. Select your game and play.