[U-Boot] Is there a better way?

[Chris Rigg]

Thanks Wolfgang. Yes, I was intending to read from the host side while the
filesystem was active on the PPC (target) side. But after hearing back from
you guys and doing some more research it doesn't seem like a good (or even
workable) solution.

At this point, I'm thinking I'll design my own host-read-target-write simple
filesystem or use the IP-over-PCI suggestion that Ira and Scott made.

Chris

On Tue, Apr 20, 2010 at 3:50 PM, Wolfgang Denk <wd at denx.de> wrote:

> Dear Chris Rigg,
>
> In message <k2m7753e5291004201201u401d9a82xa172216f44d6312b at mail.gmail.com>
> you wrote:
> >
> > My goal:
> > I need a way to get the files from the ramdisk on the PPC to the host
> over
> > PCI.
>
> Design an interface. Or use an existing one.
>
> > My solution:
> > The best idea I could come up with was to map in the PPC's ramdisk memory
> on
> > the host and then read it like I would a normal ext2 filesystem. For
> > example, let's say the ramdisk is 1MB in size. I would simply map in that
> > 1MB on the host side over the PCI bus. And then have a ext2 filesystem
> > reader tool that can look at the filesystem and extract the log files I
> > mentioned earlier. It would be like NFS but over PCI instead of ethernet.
>
> You mean you want to do this while the file system is active, i. e.
> while it is being used by the Linux running on the PPC with the
> filesystem mounted?
>
> You will run into serious trouble, quickly, as the information in the
> ramdisk is most likely inconsistent, incomplete, and changing. Keep in
> mind that Linux caches both data and meta-data.
>
>
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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>