For a look at how EBOOT files are typically used for retro gaming on the PSP:
Be cautious when downloading files claiming to be "GTA San Andreas PSP Eboot." These are often designed to exploit users looking for a non-existent port. For the most stable portable experience, San Andreas is officially available on mobile platforms (iOS and Android) and the Nintendo Switch. Gta San Andreas Psp Eboot Pbp
Users searching for this file often confuse it with similar titles: For a look at how EBOOT files are