RTEMS with post-boot code.

[Joel Sherrill]

On Wed, 29 Oct 1997, Eric Norum wrote:

> Joel Sherrill wrote:
> > But if I understand right, the original idea was just to put as
> > much in ROM as possible to minimize downloads. If something gets
> > trashed, a reset will bring a stable copy out of ROM and then you
> > can try to debug it again. I don't think the original intent was
> > necessarily concerned with being able to switch applicatins without
> > an intervening reset -- although I agree it would be a good
> > feature. I think it would personally distract from my ability to
> > debug. Who would know for sure what dmage had been done by a
> > previous executable.
> 
> A consideration with this approach is that ROM is often much slower  
> than RAM......

This is true.  I am showing off local habits here.  My tend to copy code
from ROM to RAM at resset time so I think of ROM'ed code as code you can
get back after a reset.  Running all the code mentioned (RTEMS, drivers,
BSP, C library, etc) from ROM could have a bad impact on system
performance.

--joel
Joel Sherrill                    Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
   Support Available             (205) 722-9985