This is the and only legal method. Since the PS3 firmware is free software, Sony hosts it on their official servers.

When setting up a PlayStation 3 emulator like , it is important to clarify that PS3 emulation does not use traditional "BIOS" files in the same way older consoles (like PS1 or PS2) do. Instead, you need the official PS3 System Software (firmware) to decrypt and run games. Essential Information for PS3 Firmware Official File Name : The required file is always named PS3UPDAT.PUP