Am 2020-02-10 10:59, schrieb Tudor.Ambarus@xxxxxxxxxxxxx:
On Monday, February 10, 2020 11:47:23 AM EET Tudor Ambarus wrote:
> btw. we should catch the two special cases:
> - lock none -> 0 (that was already the case)
> - lock all -> all BP bits
>
> The latter is important if "bp_slots_needed < bp_slots_available"
> because there
> are multiple settings for protect all. Most flashes will define any
> remaining
> setting for "protect all", but I've also seen flashes where the
> in-between ones
> were undefined (not mentioned) and only the "all bit set" was protect
> all.
I re-read this. Do you have such an example of flash? Aren't the BP
bits in
this case marked with "X", i.e. don't care? If not, probably we can
mask out
those undefined slots.
There was definetly some datasheet where the remaining ones wasn't
described
_and_ there was no X (don't care) bits. Unfortunately, I don't find it
right
now. That datasheed made me wonder what the other "undefinded" cases
would be.
Probably it will also be "protect all"; I just mentioned it because it
would
be an easy special case to handle. I don't think we should mask out
anything,
either use the slot in between (ie the one which the formula gives us)
to
protect all or use the largest setting (ie [TB3 |] TB2 | TB1 | TB0). And
given the reasons above, I'd prefer the latter.
This case is addressed by using bp_slot_count and bp_slots_available.
We're
in the else case from above. From bp_slot_count up to the
bp_slots_available, those slots are "protect all".
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