[U-Boot-Users] Accessing mkimage checksum

Wolfgang Denk
2006-04-27T14:58:55Z

In message <200604270900.14579.ngustavson@emacinc.com> you wrote:
>
> The target board is our SoM-5282M,
> http://www.emacinc.com/som/som5282em.htm

Maybe before asking for free help here you should feed your patches
back into the public tree.

> > I don't see
> > why "the flashing utility needs to calculate a checksum" - the uImage
> > file already has two checksums, so no new calculation should be
> > needed.
> For verification during the writing process.

You don't want to verify this "during the writing process". This
makes no sense. You probably want to verify it *before* erasing the
image in flash (so that you keep the old image if the downloaded one
was corrupt), and *after* writing has completed (so you can be sure
that the flash content is ok).

> > I have no idea what you could need special tools for.
> It needs to be an easy to use utility (This utility could be a shell script)

"mkimage" is trivial to use. It just requires the "-l" option and a
file name argument.

> I realize it's not that complicated an issue, and I could probably figure it
> out in an hour or two. But somebody's probably already done this, why not
> just ask?

I just told you: this *has* been solved. "mkimage" perfectly does the
job. No new code is needed.

> > Actually this has nothing to do with uClinux, and very little with
> > U-Boot.
> It requires a small amount of knowlege of raw access to MTD, the format used

This is standard Linux stuff and not uClinux specific.

> by mkimage, and it would be nice to know I'm not reinventing the wheel.

You don't need to know the mkimage format, as the mkimage tool is
perfectly capable of reading and checking such images.

Best regards,

Wolfgang Denk

--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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