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Date: Tue, 24 Sep 2002 13:22:37 -0700
From: Marc Singer <elf@buici.com>
To: Russ Dill <Russ.Dill@asu.edu>
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Subject: Re: Interest in DOC and YAFFS? --> YAFFS bootloading
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On Tue, Sep 24, 2002 at 11:47:43AM -0700, Russ Dill wrote:
> 
> > > cramfs is a read only filesystem not an archive format like zip or tar
> > > so you do not have to copy the data into another filesystem to use it.
> > > You use cramfs instead of initrd+filesystem.
> > 
> > That isn't really the issue here.  We're talking about using gzip'd
> > ext2 versus cramfs to do initrd.  The thing is that in my tests,
> > cramfs images are larger than compressed ext2 images.  Not what I
> > would expect.
> 
> if you are talking about an initrd, then the features of cramfs aren't
> quite as usefull, as the whole thing will be loaded into ram anyway. On
> the other side:

I see.  That is where my understanding comes from.  Now it makes sense.

> A cramfs will always be exactly as small as it needs to be, no guessing
> on an image size. cramfs is created by population, not by making an
> image, formatting it, mounting it loopback, and then copying files.

Indeed.  It can be inconvenient knowing how big to make the loopback
file.

> incedentally, I have a copy of mkcramfs with device table support (as
> seen in mkfs.jffs2) as well as permission squashing, so that a cramfs
> image can be made withoutt root (complete with suid root programs, and
> /dev entries)

I'd appreciate a copy of your mkcramfs changes.

Thanks.