[U-Boot-Users] Running uC/OS-II on top of u-boot

[David Hawkins <dwh@ovro.caltech.edu>]

Hi,

> We have a PowerPC 440 EP (from a AMCC Yosemite evaluation kit)
> and we are in the process of evaluating OSes for it. The
> industrial strength ones (like vxWorks) are too much
> feature-wise and money-wise, so we're hoping to try out uC/OS-II. 
> 
> If someone has tried to do this before, I have a few questions:
> 
> - How do you configure it to run on top of u-boot? What commands are used?
> 
> - Can the porting layer of uC/OS-II use some of the u-boot functions for PCI
> and ethernet access?
> 
> - Are there any existing instructions on how to build (or create a makefile)
> uC/OS-II using the compilers supplied by the ELDK? I keep getting a failure
> to "find entry symbol _start", even if I include the gcc libraries,
> crtbegin.o, etc. 
> 
> I appreciate any help that I can get with my questions. Thanks!

I have a Yosemite board, but haven't tried running uCOS-II
on it.

I would suggest creating a uCOS-II port that starts out life
as a U-Boot stand-alone application.

This way U-Boot sets up the processor, so your uCOS-II port
doesn't have to deal with that.

In the U-Boot stand-alone application, you would create the
first uCOS-II task and initialize it. The other tasks
would be in the same image loaded by U-Boot.

You might even get away with using U-Boots console routines,
however, since they're polled, you might want to create your
own. If you do use them, you might want to use a mutex to
protect the console routine use in multiple tasks.

This scheme is analogous to starting uCOS-II from DOS in
the Labrosse book. It should be possible to exit from uCOS-II
back to the U-Boot console too.

Cheers,
Dave