From: John Rigby <jcrigby@gmail.com>
To: Kenneth Johansson <kenneth@southpole.se>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: fastboot.
Date: Fri, 29 May 2009 14:30:57 -0600 [thread overview]
Message-ID: <4b73d43f0905291330i67c20bd3y2fa3f1a127077b74@mail.gmail.com> (raw)
In-Reply-To: <1243595599.9769.35.camel@localhost.localdomain>
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Kenneth,
I did some fastboot work for 5121 a few months ago. U-boot, kernel and
JFFS2 rootfs in NOR. My reset to userland time was 2.0 seconds, where
userland was first command executed in first rc.whatever file, so it
included the time for /sbin/init to get up and start running the rc scripts.
I did some profiling and noticed that the JFFS2 boot time was a significant
hunk (not just the first time but everytime). I ran sumtool on the JFFS2
image and it dropped 600 ms from the boot time so my final time was 1.4
seconds. The sumtool program has been around for a few years but it was
news to mean when I found it.
John
On Fri, May 29, 2009 at 5:13 AM, Kenneth Johansson <kenneth@southpole.se>wrote:
> http://www.cambridgewireless.co.uk/news/article/default.aspx?objid=36792
>
> Anybody know what they mean by booting here.
>
> I have started the ads5121 board using u-boot and kernel in NOR flash
> and root file system on a compact flash card connected to the IDE
> interface in 2.05 second until init is started from the rootfs.
>
> This was fast enough for what was needed I did not try to optimize
> further but since I already was in the domain where changes impacted
> only a few milliseconds I have a hard time imagining going down to less
> than a second.
>
> So I guess the only way is to skip u-boot and run linux kernel directly
> out of NOR. Anyone know what MontaVista is doing ??
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
>
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next prev parent reply other threads:[~2009-05-29 20:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-29 11:13 fastboot Kenneth Johansson
2009-05-29 20:30 ` John Rigby [this message]
2009-05-29 20:45 ` fastboot John Rigby
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