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 [off-list ref]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 ??

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