R: R: filling string variables in script

[Sascha Hauer]

On Mon, Apr 02, 2012 at 04:52:41PM +0200, Martino Ruppi wrote:
> 
> 
> -----Messaggio originale-----
> Da: Sascha Hauer [mailto:s.hauer at pengutronix.de] 
> Inviato: lunedì 2 aprile 2012 16.38
> A: Martino Ruppi
> Cc: barebox at lists.infradead.org
> Oggetto: Re: R: filling string variables in script
> 
> On Mon, Apr 02, 2012 at 04:28:22PM +0200, Martino Ruppi wrote:
> > I'm sorry, I renovate my previous question.
> > Or maybe it wasn't arrived to the list.
> > I appreciate if someone could put me on right trace.
> > Thanks. Marty
> > 
> > Da: barebox-bounces at lists.infradead.org 
> > [mailto:barebox-bounces at lists.infradead.org] Per conto di Martino 
> > Ruppi
> > Inviato: giovedì 29 marzo 2012 15.36
> > A: barebox at lists.infradead.org
> > Oggetto: filling string variables in script
> > 
> > Dear all,
> > I would ask a question as barebox user.
> > I mind to set a variable as result of memory reading but I understand it doesn't implemented redirection.
> > I'd like to do something of this:
> > 
> > myvar=""
> > memcpy -s  /dev/nor0.switch -d $myvar 0x0 0x0 4
> > 
> > or
> > 
> > myvar="$(cat /dev/nor0.switch)"
> > 
> > I think, I use one of last releases (version command?).
> > Thanks to everyone can help me.
> 
> If I understand correctly then you want to copy the content of /dev/nor0.switch to a variable. I'm afraid there currently is no way to do this in barebox. What information is inside this nor partition? It seems like you want to implement some kind of redundant boot and want to decide which rootfs you want to boot. Am I right?
> 
> Sascha
> 
> It's exactly as you write. 
> I mind to boot from a redundant filesystem to safety upgrade the former.
> it's no matter about /dev/nor0.switch content, now I wrote "ZERO" chars on it.
> I tried also comparing 2 blocks (memcmp) but it seems I can't get boolean answer form it.
> If you suggest another way, I can move on it.

You can access the barebox environment from Linux using
scripts/bareboxenv (I have a patch which compiles it for the target
also)
We use this in a similar setup to set a variable under Linux and read it
out under barebox to decide which rootfs to boot. If you prefer to
put this into a seperate partition you can add it using
saveenv <path_to_env> <directory> and
loadenv <path_to_env> <directory>.

Sascha


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