[U-Boot-Users] Re: FT u-boot shim

Wolfgang Denk wd at denx.de
Fri Apr 28 09:43:32 CEST 2006

In message <200604281034.26439.pantelis at embeddedalley.com> you wrote:
> You're going to carry around all the FT node building code & then patch an
> external binary blob? Or are you going to poke at hardcoded positions in 
> the blob?

I think that binary patching of pre-defined addresses is a bad  thing
to do, as it would soon cause more trouble and incompatibilities than
we have right now. So the only remaining option is ...

> And that with an extra binary blob that you have to carry around, at yet
> another danger of screwing up. How many posts in the list we're going to
> get from users that are trying to boot with a blob for their eval board,
> or worse "something they found in the internet"?

How many messages do we get today from user who misconfigured their system?

If the kernel make rules create a single file  (a  multi-file  imagew
with  the  kernel and the dts) then I don;t see much changes from the
user's point of view.

> IMHO all this talk about having shims is bunk. It is trivial for the running
> kernel to detect that a valid BLOB was passed by the bootloader. It can then
> proceed with using a preset compiled in tree for use with non OF firmware.

So you vote for keeping duplicated versions of the dts both in U-Boot
and in Linux?

> But the bootloader should pass & generate the tree, if the board maintainer
> is willing to pay the cost. 

And what is your suggestion if he is not willing to do that?

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
My play was a complete success.  The audience was a failure.

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