Basic questions re RTEMS and PPCbug

[Joel Sherrill]

David Hamilton wrote:
> 
> I'm inexperienced at working at the BSP/RTOS level and have some basic gaps
> in my understanding of RTEMS (I'm used to working with VxWorks).
> I have downloaded and compiled RTEMS for the MVME2307 board (closest thing
> to my MVME2400 and MVME2700 boards) and am trying to understand what I've
> got.

There are README's in c/src/lib/libbsp/powerpc/motorola_powerpc with
deatiled instructions on board setup and downloading.  Once you get it
working on those boards, please submit a README for those boards.

> I seem to have a number of executables in /opt/rtems/mvme2307/samples (eg
> hello.exe etc.), but nothing looking like an OS. Is RTEMS linked (or at
> least the elements of it that are required) to the application? 

You are correct.  Most of the time RTEMS is linked with the application.
Some users have implemented dynamic loading systems.  In particular,
Chris Johns' My Right Boot provides this on Coldfire and M68k platforms.
But there is not yet a general dynamic loading scheme with RTEMS.

Let me assure you that given someone willing to sponsor the effort,
there are a number of people who would eagerly work to implement it. :)

> In that
> case, am I right in understanding that there is no shell associated with
> RTEMS.

Not in the VxWorks shell sense.  There can eb a telnetd and mini-shell once
you get everything up.


> As I said, I have MVME2400 and MVME2700 boards. I've never used PPCbug
> before, so have just started trying to get to grips with it. Anyway, I'm
> trying to see if any of the MVME2307 samples will work on either board.
> I've configured the network with NIOT and changed ENV settings according to
> README.MVME2300.
> I then load hello.exe (and others) using NIOP, and it seems to get
> transferred ok.
> I try running the programe using GO but always get an INVALID error at the
> first address.

Is hello.exe a binary file or srecords?  I am not that familiar with
ppcbug either but the network load scheme for the Motorola boards 
often wants pure binary images.  The destination address must match
that in the linkcmds.

> Due to my inexperience, I'm not sure if the problem is due to
> incompatibilities between the MVME2307 bsp and my boards (although I think
> the MVME2700 is really quite close to the MVME2300 series), or whether I'm
> actually screwing up with my PPCbug commands.

FWIW it is very easy to screw the PPCbug setup and pick the wrong download
image.  So don't feel bad.  The BSP still may not work on that board
out of the box but it is more likely there is one subtle step you
have missed.  

> It is difficult at the beginning to get a foothold.
> Any advice would be welcome,
> David

-- 
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
Support Available                (256) 722-9985