Raspberry Pi's actually boot on a really fringe processor called a VideoCore. Arguably the GPU bootstraps the CPU, which makes my brain hurt.
There were many X terminals running off nothing but a Texas 34010, which was a very DSP-like CPU that ended up in a lot of high-end graphics acceleration boards for PCs and Macs (and Unix workstations).
The fact it could boot up an X server is quite extraordinary.
I wonder what the VideoCore looks like to the programmer.
Since it was designed explicitly to serve that purpose, I'm not sure why it's 'extraordinary'.
Disclaimer: I spent time at a 34010 X terminal shop.
It's true that videocore was intended to be a GPU for phones, though.
IIRC they realised that the micros were not going to cut it, they went to Broadcom (Which Eben was working for at the time) and they were able to supply some "overstock processors" for cheap, which became the processor used in the Pi. Remember at the time the Pi was never designed to be for "makers" but to be a cheap computer to help better kickstart education, it was never designed for "us", but we all said "hey, cheap little linux computer, I'll take 5!
I've come across some (unknown provenance) information that bcm2763, which was advertised as a phone chip on an old version of the broadcom website (via archive. org) was the same die as bcm2835, but with dram hooked up in a different way.
Also broadcom haven't made phones, while they do still have a strong tv/StB market share, but that's declining due to their incessant proprietary attitude
