[U-Boot-Users] Question about CFG_ENV_ADDR during RAMBOOT

[Andy Fleming]

On 5/22/07, Jerry Van Baren <gerald.vanbaren at smiths-aerospace.com> wrote:
> Timur Tabi wrote:
> > Doesn't anyone have an answer to this question?

That's easy:  It's broken.  I sort of thought it was too obvious to
bother with a response.

> >
>
> The saving grace here is probably:
> * For a RAMBOOT image, there isn't any incentive to save lots of stuff
> in the env since it (generally) disappears on a reboot and definitely
> disappears on a power cycle.


I suspect what happened is that no one uses RAMBOOT, so no one noticed
when it broke.


>
> * On the PowerPC, at least, the first 12K of u-boot.bin is the HRCW and
> vectors which aren't used by a RAMBOOT image so overwriting them is a
> non-fatal error.

Woah, there.  On *some* PowerPC, the first 12k are HRCW.  On 85xx this
is not the case.  The low 256 bytes are for the version string and
some empty space.  Then we have _start.  The exception vectors (as
Wolfgang noted) are all in that space.  So it's not a problem as long
as you never hit a Decrementer exception...

suffice it to say, I would accept any patch which fixed this.  But
left to my own devices, I don't anticipate fixing this anytime soon.


>
> * 4K is fairly large for an env, so people probably don't run into the
> problem.
>
> Best regards,
> gvb
>
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