More Mini2440 questions...

[Juergen Beisert]

Hi Zoltán,

Zoltán Kócsi wrote:
> On Mon, 4 Apr 2011 13:13:31 +0200
>
> Juergen Beisert <jbe at pengutronix.de> wrote:
> > Hi Zoltán,
> >
> > Zoltán Kócsi wrote:
> > > Thanks for all the answers for my previous questions!
> > >
> > > The 'next' branch indeed boots from the NAND FLASH like a charm.
> >
> > \o/
> >
> > Just for my list of tested min2440 variants: What type of SDRAMs and
> > NAND is your system using?
>
> The SDRAM is Micron 48LC16M16A2-75, the NAND is Samsung K9F1G08U0B.
>
> Actually, taking a look at the RAM datasheet of the reveals that with a
> 3 clock RAS->CAS latency the chip can can merrily work with a 133MHz
> bus clock, so the S3C's FCLK could be boosted up to 532MHz. A
> 30% speed increase is not something to sneeze on...

You can try. But when I read the datasheet, most of the time they only talk 
about 400 MHz max. CPU clock, and never about 533 MHz any more.

BTW: The average data throughput of a SDRAM running at 133 MHz @ CL3 is lower 
than of a SDRAM running at 100 MHz @ CL2. The CL3 hurts more than you will 
win with the increased clock.
 
> >[...]
> >
> > "/env/config" for parameterization. Maybe these file will help you to
> > understand how it works.
>
> I'll try my bestto grok them :-)
>
> > So, the changes in your environment are lost after reboot?
>
> Yes.
>
> > Do you see any kind of error message (like CRC sum errors)? when
> > barebox comes up after reset and tries to load the saved environment?
>
> No. Here's what goes on, with unimportant stuff deleted:
>
> mini2440:/ printenv
> locals:
> machine=mini2440
> [...]
> nfsroot=:/path/to/nfs/root
> [...]
> globals:
> PATH=/env/bin
>
> mini2440:/ nfsroot=/some/other/root
> mini2440:/ PATH=$PATH:/some/location
> mini2440:/ printenv
> locals:
> [...]
> nfsroot=/some/other/root
> [...]
> globals:
> PATH=/env/bin:/some/location
>
> mini2440:/ saveenv
> saving environment

Ahh, no I see the problem: You did not change anything in the environment. You 
are using barebox, not u-boot!

Try to edit the /env/config file at your mini2440 instead:

mini2440:/ edit /env/config
mini2440:/ saveenv

Think in scripts now, not in environment variables any more.

Regards,
Juergen

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