[U-Boot-Users] [rfc] warning about overlapping regions when booting with bootm

[Wolfgang Denk]

In message <200802160259.32371.vapier at gentoo.org> you wrote:
> we semi-frequently get users who try to boot an image on top of itself and
> when when things crash, dont realize why.  i put together this quick little
> warning, but i'm guessing that Wolfgang's answer is "don't bloat the code for
> stupid people" ...

Indeed I reject the patch as is, but not because I think it would be
not useful, but rather because it is IMHO not correct. 

The thing is that images *may* overlap, at least a bit. When the  de-
compressor is running, it starts from the beginning of the compressed
image  and progrsses towards the end. The already preocessed parts of
the image are not neede dany longer - if they later  get  overwritten
by  umcompressed  code  this does no hard. Problems arise only if the
write pointer catches up with the read pointer.

Unfortunaltely I don't know of an  intelligent  way  to  handle  this
situation.  I  think  I  remember that RMK claims that the ARM kernel
uncompressor was really clever in this respect, but never found  time
to check it.

Best regards,

Wolfgang Denk

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