The PRU compiler (clpru) is a TI proprietary compiler, free but licensed. It is pre-installed on BeagleBones. There's also a gcc compiler‡, but I don't know anything about it.
I didn't know about this! My last experience messing around with compiling for the PRUs was really frustrating - I gave up after about three days' screwing around with freeware tools that didn't work.
Could you point to where the PRU compiler is located on the BeagleBone file tree? I'd like to try this out!
I'd recommend using the CCS IDE (as I describe in the article) rather than the command line compiler, but it's up to you. You'll still probably encounter frustration - it's not an Arduino experience for sure.
‡ https://github.com/dinuxbg/gnupru