[iPAQ] IMPORTANT: don't use /dev/flash6

I've just received a report of someone (who will remain anonymous) who
noticed that our distribution attempts to mount /dev/flash6, and tried
writing bits into that flash partition.

Due to the industry wide shortage of flash parts, some of the early iPAQ
H3600's (e.g. H3630 and H3650's) shipped with 32 meg of flash, but current
production uses 16 meg of flash as has always been specified for the unit.
We've not had a 16 meg unit to test with here.

Unfortunately, the person had one of those 16 meg flash units. For our
demos, we had put the MP3 and MPEG files into that partition, and this
person noticed our use of that partition, and tried writing there.

So flash6 on 16 meg units wraps at 16 megabytes since the flash part does
not decode the high order bit, and he therefore overwrote the bootloader,
making his iPAQ useless.

George is building a kernel with additional checks in it that should prevent
this happening by accident in the future, and will also be modifying the
bootloader itself to lock down the flash sector where the bootloader is
stored to prevent inadvertant overwriting.

We'll make an announcement when this release with the additional sanity
checking is available (probably later today).

                                - Jim

--
Jim Gettys
Technology and Corporate Development
Compaq Computer Corporation
jg@pa.dec.com