It is completely legal and free to download directly from Sony's official website. How to Correctly Set Up a PS3 Emulator
Unlike the PlayStation 1 and PlayStation 2, which require separate BIOS dumps to boot, the PS3 operates on system firmware. Why "V1 1.7" Links are Dangerous Ps3 Emulator Bios V1 1.7 Download Fixed
[Insert installation steps]
Downloaded exclusively from the official project website. It is completely legal and free to download