Re: [ECOS] Redboot from scratch

[Gary Thomas <gary at mlbassoc dot com>]

On Tue, 2004-10-05 at 09:37, Anthony Tonizzo wrote:
> Hi:
> 
> I am about to boot a new design, and I have no way of pulling the
> flash chips for programming but I do have a "wiggler" type of
> device, that I can use to load and run an elf program into my target. 
> 
> Before using an in-circuit flash programmer I considered the option 
> of compiling a RAM version of RedBoot, download that with the Wiggler
> and then using this version of RedBoot to store a more permanent
> ROM version in flash. This way I can take advantage of the good
> support that RedBoot already has for different flash devices.
> 
> I tried to do this, but I was not successful. I do not seem to be
> able to compile Redboot so that, when downloaded, it locates itself at 
> the start of memory (I am using a PowerPC). There is always an offset 
> added to it, although the actual code seems to be compiled to run in 
> the right place (yes, I disassembled some of the early code...)
> 
> All the documentation I read seems to rely on the fact that the
> target already has a working Redboot, or that is can be "flashed in"
> by means of an expternal programmer.
> 
> Before I expend more effort into this, I would like to know if it is
> even possible, and if it is, whether there is someone out that that
> can share some ideas.

This is how I normally put RedBoot/eCos onto a new board.  Just build
a RAM version - it doesn't matter that it wants to start at an
address other than 0.  Download it using your wiggler and start it
at the beginning.  Once you have the RAM version working, you can add
in FLASH and networking drivers.  Then use the RAM version to write 
the ROM (or ROMRAM) version to FLASH and you should be off and running.

-- 
Gary Thomas <gary@mlbassoc.com>
MLB Associates


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