On 7/5/06, Olin Lathrop <olin_piclist@embedinc.com> wrote:
> Mark Rages wrote:
> > My plan was to write a program to disable write
> > protection on the boot block, change the byte, then re-enable write
> > protection.
>
> *Think* about it.  Write protection is there to prevent writes to program
> memory.  It's purpose would be defeated if you could disable it from the
> program.
>

For a bootloader, my misconception makes as much sense than the way
the PIC actually works.

Imagine a program that writes zeroes to all the WRTx config locations.
 This will entirely disable a bootloaded device as surely as
overwriting the bootloader would.

I suppose the only safe thing for a bootloader to do is set (to 0) the
configuration write protect bit WRTC.  Maybe it is common for
bootloaders to do this; my only data point is the PICkit 2 bootloader,
which does not.

Think about it, won't you?  Thank you.

Regards,
Mark
markrages@gmail
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