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RE: Load Redboot RAM through serial


> 
> 
> On Fri, 2001-09-21 at 08:56, Trenton D. Adams wrote:
> > How would you go about doing this though?  The bootloader 
> code in ROM 
> > is not changeable and only loads 2K of code into SRAM for running.  
> > Does eCos/RedBoot have a utility <2K that will load RedBoot 
> into RAM 
> > and run it?
> 
> Here you're talking about the specifics of a paritcular chip[set].  
> 
> On the Cirrus Logic chips [your reference], we have to use a program 
> provided by CL.  We download this program using the 
> "bootstrap" mode on the processor.  That program then starts 
> up a secondary process which loads RedBoot and writes it to 
> FLASH.  Of course, this mode of operation is very specific to 
> that particular processor.
> 
> I understand your problem though - you can't use the provided 
> code (which came to us only in binary form) since the FLASH parts are 
> different.  In this case, it may be necessary to write a small 
> replacement for the "download and FLASH" program which only 
> downloads RedBoot and then runs it.  This may prove difficult 
> as IIRC the memory map changes when in bootstrap vs normal modes.

It's just a reverse chip select decoding anyhow so that's not too much
of a problem.

I was given the code from Cirrus Logic (source form) so I'm going to be
modifying it.  That's what I'm doing in the "--entry=" topic.  Trying to
compile/assemble it for loading.  I'll probably modify the download
utility for the edb7xxx to load the boot code from a file instead of the
buffer.  That way people will be able to integrate flash support for
whatever chips they want, and simply recompile the boot loader.  I
talked to the guy there and he said the code is free and can be
integrated into the eCos repository.  If you want to, email me privately
at "tadams@extremeeng.com", and I'll give you his email address.  You
can talk to him about legalities.

> 
> Another possibility to consider might be a special version of 
> your hardware with the FLASH device in a socket which you 
> could then remove and program remotely.

To late for that, the board is already layed out and almost populated!
:)


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