Viable PPC platform?
Eugene Surovegin
ebs at ebshome.net
Thu May 11 02:48:10 EST 2006
On Wed, May 10, 2006 at 12:11:41PM +0100, Alex Zeffertt wrote:
> On Tue, 9 May 2006 10:15:20 -0700
> Eugene Surovegin <ebs at ebshome.net> wrote:
>
> > On Tue, May 09, 2006 at 05:41:01PM +0100, Alex Zeffertt wrote:
> > > On Tue, 09 May 2006 10:38:19 -0400
> > > geneSmith <gd.smth at gmail.com> wrote:
> > >
> > > > I have a ppc405gpr system with 64M ram and 4Meg flash in a
> > > > AM29LV320. Is this a viable platform for linux? Can a filesystem
> > > > (JFFS2?) be put this flash type?
> > > >
> > >
> > > I would create an initrd and put every file that doesn't need
> > > to be changed persistently into it instead of JFFS2.
> >
> > After many years of doing embedded Linux stuff I still don't
> > understand why people are so fond of initrd.
> >
> > For temporary stuff - tempfs is much better and flexible. For r/o
> > stuff - just make separate MTD partition (cramfs, squashfs) and
> > mount it directly as root. Both options will waste significantly
> > less memory.
> >
>
> Okay, let me qualify my answer. It depends on whether you need to
> make persistent changes to the filesystem in flash. If so, and given
> that your flash is only 4MB, I would recommend moving files to
> somewhere else, e.g. an initrd, because if when a JFFS2 FS is
> approaching full, you often find that writes to flash hang
> while JFFS2 searches for blocks to use as a scratchpad. This has been
> my experience anyway.
>
> If you don't need to make persistent changes to files, then I'm sure
> cramfs in flash as a rootfs would work well, with a tmpfs partition
> mounted on /tmp and /var.
You missed my point. initrd should be stored somewhere - in the same
flash . In this case there is no reason to actually use initrd instead
of just direct mount from flash.
--
Eugene
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