Freedom Fry has announced his port of ucLinux to the PSP.
From the original Post:
This is a Release for all the non believers and elitist "hackers" in the "scene". After some weeks of hacking i made it. Yet another time the REAL breakthrough stuff comes from FRANCE!!!
WARNING: It doesnt do anything useful yet. It also runs in kernel mode which means incase of a malfunction anything could happen including bricking your PSP (although very unlikely, i have run it a hundred times during development).
I will release the source (or maybe only patches) in the next days. Give me some time to recover first.
More info
A tiny Bootloader made with the opensource PSPSDK is used to initialize the Memory and a little bit of the Hardware. It decompresses the ucLinux kernel into Userspace and runs it. Currently it relies on the Display Hardware beeing initialized by the PSP Operating system (and PSPSDK) to make the Framebuffer Console work. As you can see from the dmesg, this is also pretty much the only thing that works at all.
Screenshots and Download Via Comments
EDIT by DraconumPB: Beware of this software until it is fully tested! A version of this runs on iPod as well, but I have in the past bricked a first-gen iPod by installing this (it did run but eventually caused an endless boot-loader loop). As stated it runs in kernel mode and therefore can really mess with your PSP and cause damage to your PSP that can't be repaired. However, this is still an excellent effort towards linux running and operating on PSP without emulation!