From: Marek Vasut <marex@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] arm: pxa: PXA270 D-Cache as ram
Date: Tue, 21 May 2013 12:54:59 +0200 [thread overview]
Message-ID: <201305211254.59982.marex@denx.de> (raw)
In-Reply-To: <1369132962.20319.3.camel@host5.omatika.ru>
Dear Sergey Yanovich,
> Dear Marek Vasut,
>
> On Tue, 2013-05-21 at 12:39 +0200, Marek Vasut wrote:
> > > 2.2.5.2 of Marvell PXA27x Processor Family Developers Manual says:
> > > "The PXA27x processor cache configuration is identical to that of
> > > the PXA255 processor."
> > >
> > > As a result, it is perfectly legitimate to use PXA25X
> > > 'lock_cache_for_stack' on PXA27X as well.
> >
> > Why would you need this on PXA27x ? Is SRAM not enough?
>
> SRAM is battery-backup.
SRAM is just the in-CPU bit of fast RAM. What do you mean by "battery-backup" ?
> It can be used as a ultra-fast persistent
> storage in OS. Wasting a quater of it just to boot the system isn't the
> best choice.
The SRAM is used for stack in U-Boot until you leave board_init_f, then the
stack is relocated to DRAM. The OS can use SRAM as needed, U-Boot is no longer
operational once you load subsequent OS. What's the problem?
Best regards,
Marek Vasut
next prev parent reply other threads:[~2013-05-21 10:54 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-20 22:06 [U-Boot] [PATCH] arm: pxa: PXA270 D-Cache as ram Sergey Yanovich
2013-05-21 10:39 ` Marek Vasut
2013-05-21 10:42 ` Sergey Yanovich
2013-05-21 10:54 ` Marek Vasut [this message]
2013-05-21 11:23 ` Sergey Yanovich
2013-05-21 11:38 ` Marek Vasut
2013-05-21 11:56 ` Sergey Yanovich
2013-05-21 15:00 ` Marek Vasut
2013-05-21 16:31 ` Sergey Yanovich
2013-05-21 19:02 ` Marek Vasut
2013-05-21 19:18 ` Sergey Yanovich
2013-05-21 19:24 ` Marek Vasut
2013-05-21 19:42 ` Sergey Yanovich
2013-05-21 20:07 ` Marek Vasut
2013-05-21 20:24 ` Sergey Yanovich
2013-05-21 21:38 ` Marek Vasut
2013-05-22 13:02 ` Sergey Yanovich
2013-05-22 13:04 ` Marek Vasut
2013-05-22 13:21 ` Sergey Yanovich
2013-05-22 13:54 ` Marek Vasut
2013-05-23 17:43 ` Mike Dunn
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=201305211254.59982.marex@denx.de \
--to=marex@denx.de \
--cc=u-boot@lists.denx.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