Re: [ECOS] linking a program for download to at91sam7x-resident redboot

[Robert Brusa <bob dot brusa at gmail dot com>]

On Fri, 20 Mar 2009 16:14:37 +0100, Chris Zimman <czimman@bloomberg.com>  
wrote:

> > Then I wanted to change my little hello-program by linking it in such a
> > way to go above redboot in the flash. Actually I placed it at
> > 0x00120000 -
> > far above redboot - by editing the ecos-provided target.ld-file. The
> > memory-statement in this file now reads like this:
> >
> > MEMORY
> > {
> >      ram : ORIGIN = 0x00200000, LENGTH = 0x20000
> >      rom : ORIGIN = 0x00120000, LENGTH = 0x80000
> > }
> >
> > However, when running the linker, it produces errors and reports
> > vectors
> > etc. to be out of rom range. Correct, but I think I do not need these
> > vectors here. What else do I have to change in the loader file (or
> > elswhere) to get a linked program to be downloadable to/with redboot
> > where
> > it will be launched by a cor. redboot command (or a script later on)?
>
> I'm assuming you're going to relocate this into RAM (eg. you're using  
> FIS,
> and the 'load') before running.
> If that's the case, you don't need to change the target.ld file.   
> Apologies
> in advance if I'm mistaken, but
> a little more info on what exactly you're doing would be useful.
>
> --Chris

Hi Chris
well, this little hello-program I want to launch from redboot is just my  
example to climb the learning curve of how it has to be done. The  
code-part of the program I ultimately want to launch from redboot is too  
big to go into RAM. So it has to run from flash.  And I need redboot to  
have a loader on board, so the application can be updated if required.  
Unfortunately I can not use the bootloader that comes with all  
AT91SAM7x-based systems, because it (SAM_BA) supports USB and the serial  
debug-I/F only and both of them are not implemented (not accesible) on the  
board I am using here - hence (a minimum) redboot was identified as the  
solution of the problem.

The FIS in my case only has to take a small script that launches my big-ap  
if UART0 or UART1 does not receive a ctrl-c character during a timeout  
interval of a few seconds. In such a case it would abort the script and  
one would be able to use redboot for downloading a program (direct load  
into flash).  Any comments on these ideas?
  Regards, Robert

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