[U-Boot] [PATCH 0/1] Fix hang trying to protect flash sectors

[Chris Packham <judge.packham@gmail.com>]

Disclaimer: I'm workmate of Mark's

Wolfgang Denk <wd <at> denx.de> writes:
>
> It's not a hardware bug, but a configuration error.
> 
> > f8000000-fbffffff   64M Flash 
> > fe000000-fe0fffff    1M Battery-backed RAM 
> > ff000000-ff00ffff   64K On-board logic 
> > ff700000-ff7fffff    1M CCSR 
> > fff00000-ffffffff    1M Flash (mirror of f8000000). 
> 
> This makes no sense. Fix your memory map, and map the flash (all of
> it) to the end of the address space.

While it would be possible to shuffle the memory map around there is one
problem with the hardware design that I don't think can be overcome (I'd
love to be proven wrong). The boot chip select is mapped to the _bottom_
of the first flash chip. It was done this way so that we could expand the
flash in the future as a rolling production change (we're now shipping
units with 64MB fitted). i.e. we knew we could rely on a fixed base
address so thats where we pointed the boot chip select.

I think in hindsight we could have modified our flash detection code to
start at the top and jump backwards looking for extra chips. Unfortunately
we're not able to change the hardware design for this product but we can
take this into account on future designs.

> > NOTICE: This message contains privileged and confidential
> > information intended only for the use of the addressee
> ...
> 
> And please stop posting these silly disclaimers.
> 

Corporate overlords have been flogged :). General response has been to go
sign up to gmail. Trust me it annoys us as much as it annoys you.

- C