[U-Boot] u-boot newbie

[Wolfgang Denk]

Dear David Kaplan,

In message <62564a490910270526yf6e831bt869695b71a70c229 at mail.gmail.com> you wrote:
>
> Yesterday I was a JTAG newbie - today I'm a u-boot newbie as well and I was
> wondering if anyone could help me out.

By extrapolation you will be a Linux newbie tomorrow, an apprentice in
a week and an expert in a month from now. Or so.

> I've managed to get my hands on a surplus gps board (have no idea what gps).

Isn't there _any_ name or type code on that board?

> The board has a samsung s3c2410 chip (arm9), samsung k9f5608u0d 32M flash
> mem and two Qimonda HYB25L256160AF-7.5 (SDRAM) chips (16Mbit x 16
> organisation I think).
> 
> My JTAG interface works fine and I can communicate with the chip (I have
> managed to dump the flash too - i think).

Then try to find out what's in the flash. Use hexdump and "strings -a"
etc. - with any luck, there was U-Boot and Linux running on that box,
and you can ask the manufacturer for the source code.

> I would like to know where to begin in regards to building a u-boot config
> for this setup. Is there a ready-made config I could use (or edit?) Or some
> documentation on how to build a config from first principles?

There is a porting guide in the README. Not joking.

But keep in ming that an essential prerequisite for performing a port
in a somewhat efficient manner is a thorough understanding of both the
processor architecture and the board design. Normally you will need
schematics for the board (unless you are lucky in such as the board
was derived from some well-known evaluation kit, and you manange to
guess from which one - and manage to get the documentation for this).

> Also, once the u-boot has been compiled - where do I flash it to? (which
> location in the flash mem - apparently it's not a good idea to overwrite the
> first 4k???)

We cannot tell you. You must know the design of this board, with  all
these  little details, probably including many more things - like how
to set (and eventually enable) clocks and outputs, how  to  power  on
and/or reset and/or initialize the peripherals on your boards, etc.
You need detailed hardware documentation. And experience.

Alternatively, you need a LOT of time (after which you eventually may
have gathered some experience).

Best regards,

Wolfgang Denk

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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
No problem is insoluble.
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