Earlier we reported on the Bochs x86 emulator being ported to the PSP by Matan. This is indeed true and has opened the door for a wide range of options that the PSP can now do, not limited to but including the running of: FreeDOS, Linux, DLX Linux, NetBSD, OpenBSD, PicoBSD, Pragma Linux, Debian 3.0r0 and 2.2r5, and any other disk images with pre-installed systems on them. Downloads on the site… Link. I can confirm that the Linux and DOS ones worked on my PSP (photos here). Remember- don’t ever update your PSP firmware to 2.0, homebrew rules.
DOS & Linux files premade files to try on the PSP