after some time of evaluation of software architecture for Multipilot32 I decide to put on it a Real Time Operating Systems.
Instead of choose FreeRtos or other clone . I found this interesting operating system that yet support HAL .
Above there's an introduction of Chibi OS , what do you think about ? My idea is to rewrite the lib of our Arducopter project using a professional approach with a Realtime Kernel on low level OS call.
A video of Chibios User that develop his quadcopter ... :)
I'm waiting your feedback :)
This is official Discussion Thread : http://www.virtualrobotix.com/forum/topics/multipilot32-need-a-rt-o...
Chibios Introduction :
This document will help you understand what ChibiOS/RT has to offer in a world with so many similar products.
Why another RTOS:
The first question to be answered is: there was really the need for yet another RTOS? There are several reasons:
How is different ?
Well, there are some design choices that should be explained and contribute to make ChibiOS/RT a peculiar design. Nothing really new in itself but the whole is interesting.
Not Just a scheduler.
While the ChibiOS/RT kernel can be used even alone, see the General Architecture document, the RTOS also offers other subsystems:
Everything in the kernel is static, nowhere memory is allocated or freed, there are three allocator subsystems but those are optional and not part of core OS, dynamic services are built as a layer on top of the fully static kernel.
Safety is something you design in, not something you can add later, using memory allocation in the kernel is unnecessary and relying on that is just asking for trouble.
No Internals structure and tables.
The kernel has no internal tables, there is nothing that must be configured at compile time or that can overflow at run time, no upper bounds, the internal structures are all dynamic even if all the objects are statically allocated.
System APIs have no error conditions, all the previous points are finalized to this objective. Everything you can invoke in the kernel is designed to not fail unless you pass garbage as parameters, stray pointers for examples. The APIs are not slowed down by parameter checks, parameter checks (and consistency checks) do exist but only when the related debug switches are activated.
All the static core APIs always succeed if correct parameters are passed. Exception to this rule are the optional dynamic APIs that, of course, can report memory exhausted.
Each API function should have the parameters you would expect for that function and do just one thing with no options.
Note, first “fast” then “compact”, the focus is on speed and execution efficiency and then on code size. This does not mean that the OS is large, the kernel size with all the subsystems activated weighs around 5.5KiB (STM32, Cortex-M3), see the section ”Performance and Testing Data” for more details about performance and footprint.
It would be possible to make something even smaller but:
I think it is nice to know how an OS is tested and how it performs before committing to use it. Test results on all the supported platforms and performance metrics are included in each ChibiOS/RT release. The test code is released as well, all the included demos are capable of executing the test suite and the OS benchmarks. See the section ”Performance and Testing Data” for more details about performance and footprint.