RE: [ECOS] Load Redboot RAM through serial

[Gary Thomas <gthomas at redhat dot com>]

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.

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.

> 
> -----Original Message-----
> From: Gary Thomas [mailto:gthomas@redhat.com] 
> Sent: September 20, 2001 4:27 PM
> To: Trenton D. Adams
> Cc: 'Fabrice Gautier'; 'eCos Discussion'
> Subject: RE: [ECOS] Load Redboot RAM through serial
> 
> 
> On Fri, 2001-09-21 at 01:08, Trenton D. Adams wrote:
> > I was thinking more along the lines of actually starting it through 
> > the serial port.  eg. loading it as the boot program.  I need this 
> > because we're changing FLASH from intel to AMD am29xxxxx.  So, using 
> > another boot monitor won't work because you have to be able to program
> 
> > flash in the first place.  Since all the boot/debug monitors for the 
> > board are designed for the flash that's on the development board, I 
> > won't be able to use that flash.
> > 
> > In particular, I would like to be able to start a RAM version of 
> > RedBoot by loading it through the serial port.  I could then modify 
> > just the Redboot source to use the FLASH that we are using.  This 
> > would be all I need since I could then write a ROM version of redboot 
> > to FLASH for startup.
> > 
> 
> We go through exactly this process all the time as part of bringing up
> RedBoot on new hardware.
> 
> Have you tried it?  If so, what problems did you have?
> 
> > -----Original Message-----
> > From: Fabrice Gautier [mailto:Fabrice_Gautier@sdesigns.com]
> > Sent: Wednesday, September 19, 2001 10:25 PM
> > To: 'Trenton D. Adams'; 'eCos Discussion'; 'Trenton D. Adams'; 'eCos
> > Discussion'
> > Subject: RE: [ECOS] Load Redboot RAM through serial
> > 
> > 
> > 
> > 
> > > -----Original Message-----
> > > From: Trenton D. Adams [mailto:tadams@theone.dnsalias.com]
> > > Subject: [ECOS] Load Redboot RAM through serial
> > > 
> > > Is it possible to have Redboot start right after being loaded 
> > > through the serial port on an edb7xxx board?  I know, anything is 
> > > possible! ;)
> > > 
> > > Has anyone ever done this?
> > 
> > I've done this on the ARM Integrator Board.
> > 
> > I Used default redboot template then change startup to RAM. Loaded the
> 
> > image with the ARM Boot Monitor et voila...
> > 
> > Regards,
> >