I'd like to experiment using the Raspberry Pi for some different low level embedded applications. The only problem is that, unlike the AVR and PIC microcontroller boards available, Raspberry Pi typically runs an OS (like Raspbian) that distributes CPU time across all running programs and makes it impractical for certain real time applications.
I've recently learned that, assuming you have a bootloader like GRUB installed, running a C program on x86 (in the form of a kernel) takes very little actual setup, just an assembly program to call the main function and the actual C code.
Is there a way to achieve this with a Raspberry Pi?
It'd be a great way to learn about low level ARM programming, and it already has a few complex peripherals to mess around with (USB, Ethernet, etc.)
While bare metal is possible on the Pi, I would avoid it since Linux is getting so lightweight and handles a whole bunch of stuff for you.
Here's a tutorial to get you started if you want to still learn bare metal stuff: http://www.valvers.com/open-software/raspberry-pi/step01-bare-metal-programming-in-cpt1/
With all that said, I would just load up your favorite embedded linux distro (RT patched might be preferred based on your requirements) and call it good.