Help With coldfire needed

[Joel Sherrill]

Alan Cudmore wrote:
> 
> My basic questions are:
> 1. What is the best version of GCC to use for the coldfire?

There are a lot of general embedded people still on 2.95.3 plus
patches.  I think the 3.2.x series is OK for coldfire RTEMS use.

> 2. Do I need patches on GCC to make the coldfire work?

No for the RTEMS tools.  Although there are (as always) outstanding
PRs on the Coldfire.

> 3. Is the version of RTEMS I am using tied to a particular version of
> GCC ?

Not as much as it is tied to newlib.  
 
> Right now I'm using RTEMS SS 11182002, Gcc 3.2 and binutils 2.13.1.
> Should I be using GCC 2.95 with special coldfire patches? If so, can I
> still use RTEMS SS 11182002 with the 2.95 GCC?

You SHOULD be able to use newlib 1.11.0+patches and current RTEMS with
any reasonably modern version of gcc.  I would be happy to see you
get gcc 2.95.3 work with newlib 1.11.0 and RTEMS because 2.95.3 is the
last gcc with known good support for at least the i960.

> Thanks,
> Alan
> 
> Read on for more details:
> 
> I need some advice on using RTEMS on the Coldfire. I'm trying to get a
> BSP working for the MCF5307C3 Eval board and here is where I am so far:
> 
> 1. I started with RTEMS ss 11182002, GCC 3.2 and binutils 2.13.1.
> 2. I was able to clone the MCF5206elite libcpu and bsp as my starting
> point. I can build the BSP and examples without error.
> 3. I carefully went through and "transformed" the 5206elite bsp into my
> 5307C3 bsp. I have double checked every bit in the register definitions.
> 4. I can load up and run the RTEMS examples for the most part, but the
> console and UART output just does not seem to work. If I write the
> characters that my UART driver is supposed to be outputting into RAM, I
> can run & dump RAM and see the results of hello.exe, paranoia.exe,
> ticker.exe etc..
> 
> In an effort to verify that I can get do something with the UART, I set
> up a minimum.exe example that does not include the console or clock
> drivers, then I cut and pasted a small Polled UART initialization
> routine and putchar into that example. I'm just trying to initialize the
> uart and put out a couple of characters in polled mode. I verified the
> addresses of all of the uart registers, and I double checked how they
> are being programmed, but I just cant seem to get the uart output
> working..
> 
> I'm starting to suspect that maybe GCC 3.2 might not be ready for the
> coldfire.

It's not that broken. :)

Are you using volatile on the pointers to the registers?  It could be 
optimizing them away.

> Any help would be appreciated,
> Alan

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
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