From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
To: Sascha Hauer <s.hauer@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH] pbl updates
Date: Wed, 3 Oct 2012 13:37:43 +0200 [thread overview]
Message-ID: <20121003113743.GE26553@game.jcrosoft.org> (raw)
In-Reply-To: <20121003100659.GC1322@pengutronix.de>
On 12:06 Wed 03 Oct , Sascha Hauer wrote:
> On Tue, Oct 02, 2012 at 08:36:41PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > On 18:50 Tue 02 Oct , Sascha Hauer wrote:
> > > On Tue, Oct 02, 2012 at 04:30:11PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > > > On 15:06 Tue 02 Oct , Sascha Hauer wrote:
> > > > > Here are two updates for the MMU code in the decompressor. The first
> > > > > one may come in handy when a JTAG debugger is connected. The second
> > > > > one is more important. It actually makes turning on the MMU in the
> > > > > decompressor useful by making map_cachable work. It turned out that
> > > > > this didn't work leaving the whole mapping uncached.
> > > > > Note that the code in current master should work, but slow. Since
> > > > > it actually does work I do not want to put this into the upcoming
> > > > > release.
> > > > As I report the current code does not work on at91sam9g45
> > > > I suspect as we boot from the second ram controler on this SoC
> > > >
> > > > So please hold the release that I can try those patch on sam9g45 if they fix
> > > > the PBL they will be mandatory for it
> > >
> > > I think they won't fix it. map_cachable currently is a noop, but this
> > > should be fine as now we have a complete 1:1 uncached mapping. I don't
> > > see why this shouldn't work. I hope you find out.
> > >
> > > What we can do for now is to add an additional Kconfig option to make
> > > enabling the MMU in the pbl optional. Then at least it should work on
> > > your boards.
> > Was thinking about this too
>
> Ok, I'll prepare a patch.
>
> > >
> > > BTW I hunted down a strange problem with the MMU on a KaRO Tx53 board.
> > > It turned out that the image header (which basically is a poke table
> > > to initialize the SDRAM) indeed initialized the SDRAM. The problem was
> > > that this SDRAM setup depends on some other lowlevel setup which is done
> > > later. The SDRAM setup was good enough to load with MMU disabled, but
> > > once the MMU is enabled the SDRAM does burst accesses and the board goes
> > > to nirvana.
> > > Maybe your problem is related somehow.
> > yeah It may solve my issue with the MMU and nand boot
> >
> > I was thinking to add a initcall support to the pbl and enable the MMU at the
> > right momment. This will allow to simplify the adding of generic SPL framework
>
> I don't think this is a good idea. I don't want to grow a second
> bootloader in the pbl. It should stay simple.
I want to add spi boot and mmc boot where the non shell barebox is too big to
fit in sram
Begards,
J.
>
> Sascha
>
> --
> Pengutronix e.K. | |
> Industrial Linux Solutions | http://www.pengutronix.de/ |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox
next prev parent reply other threads:[~2012-10-03 11:40 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-02 13:06 Sascha Hauer
2012-10-02 13:06 ` [PATCH 1/2] ARM pbl: Provide a dummy error function for the decompressor Sascha Hauer
2012-10-02 13:06 ` [PATCH 2/2] ARM pbl: actually create cached mappings in " Sascha Hauer
2012-10-02 14:30 ` [PATCH] pbl updates Jean-Christophe PLAGNIOL-VILLARD
2012-10-02 16:50 ` Sascha Hauer
2012-10-02 18:36 ` Jean-Christophe PLAGNIOL-VILLARD
2012-10-03 10:06 ` Sascha Hauer
2012-10-03 11:37 ` Jean-Christophe PLAGNIOL-VILLARD [this message]
-- strict thread matches above, loose matches on Subject: below --
2012-08-10 20:00 Sascha Hauer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121003113743.GE26553@game.jcrosoft.org \
--to=plagnioj@jcrosoft.com \
--cc=barebox@lists.infradead.org \
--cc=s.hauer@pengutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox