20 seconds boot requirement (was: Hello -- NAND/NOR Flash design for GTA02)

Michael 'Mickey' Lauer mickey at openmoko.org
Fri Jan 11 13:47:36 CET 2008

cc'ing to distro-devel, these guys should be involved in decision
processes like that.

Andy Green wrote:
> One of the choices that we may do is to cut rootfs into two, because the
> amount of time spent mounting is proportional only to the partition
> size.  We can create a 50MB "early boot" partition we can mount to get
> started with the initscripts, and mount the remaining 200MB in the
> background at a different mountpoint.  This will reduce the effective
> initial JFFS2 mount time to 20% of what it is now.

I'd really like someone to try yaffs2 instead of starting to partition
the flash.

As for the userland speed up...
Graeme, how far are you with upstart integration?

> Werner is looking at trying to find a different way to optimize the
> mount time, we said that early next week we will finalize the decision
> on the partition set we will use, but I would propose we cut the rootfs
> in two as described if Werner didn't have luck in speeding it up by a
> considerable amount.  Of course even if he speeds it up by 5% that is
> really good either way.

> If we go that way, we need to consider the impact on packaging paths.
> Probably we should leave all the packages to point where they are, and
> have /usr and so on in the "early boot" partition.  Then other packages
> should place stuff in something like /opt or /usr/local which is mounted
> or mounted --bind to the second, larger partition.

From a distro developer standpoint, I really don't like all that. This
is a massive workaround that may generate more work than going for
yaffs and upstart or fixing jffs2.



Dr. Michael 'Mickey' Lauer | IT-Freelancer | http://www.vanille-media.de

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