Check out this cool PSP hack! Someone ported uClinux to a PSP! :p
uClinux is a open-source linux for small embedded applications. You have no royalty to pay for
after you develop an application which is the benefit over the royalty attached RTOS
(Real Time Operating Systems). Micrium has some cool RTOS but I think you have to pay like
$10,000 just to get started…
Depending on your perspective, maybe a lot, maybe nothing. It has minimal hardware support (the headphone jack serial port has a TTY driver, and, well, thats it really. Unless you count the CPU and the RAM.)
It boots. It mounts a root filesystem that is linked in with the kernel code. It loads an interactive shell and has a very minimal userland. At the moment, every binary is statically linked.
This is mainly a proof-of-concept. Hopefully now more people will help, and we can write device drivers for all the remaining hardware thats on this nifty little handheld.