[U-Boot] Is there a better way?

[Ira W. Snyder <iws@ovro.caltech.edu>]

On Tue, Apr 20, 2010 at 04:03:01PM -0600, Chris Rigg wrote:
> Thanks guys. I'll take a look at this in more depth. It sounds like this
> would be the suggested solution to my problem.
> 
> Is there an example somewhere that you could point me towards?
> 

As this is a bit off-topic on this list, I'll reply to you with the
patches attached. If anyone else wants the code, please ask me.

Linux is seriously lacking a general purpose solution here. I've made
some attempts at writing one, but haven't had the time to complete them.
I'm happy to test a general solution anyone comes up with. I've been
suggested that virtio would be a good choice here, since they have a
highly optimized network driver.

Ira

> On Tue, Apr 20, 2010 at 3:37 PM, Scott McNutt <smcnutt@psyent.com> wrote:
> 
> > Hi Chris,
> >
> > Ira W. Snyder wrote:
> >
> >> My problem:
> >>> If I have an in-memory filesystem on my board (the ramdisk), and I have
> >>> the
> >>> entire 256MB of memory accessible to the host over the PCI bus, you'd
> >>> think
> >>> I could write a tool (or find a tool) that I could point at a block of
> >>> physical memory and have it recognize it as an ext2 filesystem and read
> >>> it
> >>> as such. Unfortunately, there doesn't appear to be a precedent for doing
> >>> this. Is there a better way to accomplish my goal of getting my logs off
> >>> the
> >>> ramdisk on the board from the host?
> >>>
> >>>
> >> I've solved a relatively similar problem here. I have a
> >> mpc8349emds-based board that is a PCI target. I've written a couple of
> >> smallish drivers for U-Boot and Linux that make the board seem like an
> >> ethernet interface.
> >>
> >
> > Ditto. Ira's suggestion is a very elegant and useful technique ... and
> > has been used successfully for many applications.
> >
> >
> >  We tftp our kernel and boot our board over NFS using the "ethernet"
> >> interface.
> >>
> >
> > As Ira suggests, once your target appears as an addressable host, the
> > sky's the limit. You can telnet/ssh into your target, run tftpd,
> > run a web server for configuration/status, etc. Cool stuff!
> >
> > Regards,
> > --Scott
> >
> >