ChibiOS Free Embedded RTOS

Hi there,

This is a some what general question. I'm relatively new with RTOS operating system concepts. I have now read the book by D. Comer, "Operating System Design - The Xinu approach 2nd ed", primarily because the documentation of Chibi recommends it. I must say i liked it a lot, and have played around with the code for some time now. Also, I have done some small testing with ChibiOS/RT and read the 'book'. There are of course some obvious differences between these 2, but i was wondering if anyone who have read the book can tell me if there are any fundamental differences in design choices between these 2, and the reasoning behind. Especially concerning the implementation of context switch, priority handling, IPC and so on. Well, maybe there is no good answer to this, but worth a try to ask before digging in to the source code of Chibi.

Thanks in advance.

Regards,
Rasmus Steffensen.

Hi,

ChibiOS/RT has been created by someone who used that book for learning so there are some things in common, the use of a ready list and a delta list for example, also the context switch method is reminiscent of the one used in Xinu (direct synchronous task to task switch).

I started porting Xinu on a 68K in 1987 but then I decided to create something entirely different, it was the ChibiOS/RT grandfather, something called "BDP". It was an Unix-like full OS, it ran on an Atari ST and was complete enough to run emacs, GCC and all the GNU utilities, it was natively multi-threaded and realtime too. From that I derived an RTOS called "mk" and from mk, 15 years later, ChibiOS/RT

BDP never went pubic but "mk" is available in SourceForge files area for historical reasons.

Giovanni