[coreboot] flashrom: Support Pm49FL004/2 Block Locking Registers

[Stefan Reinauer]

Peter Stuge wrote:
> On Sat, May 17, 2008 at 03:12:05AM +0200, Stefan Reinauer wrote:
>   
>> Instead of locking the chip, should we put it back to the state it
>> was before? Does this make sense?
>>     
>
> Good question. Actually I don't see why it would matter at all, what
> matters is to unlock in order to erase or write.
>   
> I don't think any other part of flashrom bit twiddling does restore,
>   
Yes. They all leave it open, as they do with the board enable and the
chipset enable. This is a very high security risk.

> I'm not sure it actually matters anywhere?
>   

Well, "It's broken everywhere else"... I figured it matters to some
extend, as you put the locking back in place. If you were inspired by
the other chips, you would have let the protection open ;-)

> I guess our policy is to leave bits unlocked. 
Not a policy. If we want a policy, it can not be anything but "We leave
the same way as we came"

Stefan