chip footnotes/different voltages on chips with shared IDs (was: Zotac ZBOX-AD02-PLUS-U: System Testing)

[Stefan Tauner]

On Sun, 8 Apr 2012 20:26:16 -0700
Svetoslav Trochev  wrote:
> Hi Everybody,
>
> After sourcing W25Q32BV chip, I successfully finished the test of
> Zotac ZBOX-AD02-PLUS-U system.

thanks, i have added the board to our list and will commit it later
together with other small changes.
> P.S. I notice that in the WIKI page the Winbond W25Q32 is listed as
> 2.7V ~ 3.6V chip, but in my search I found out that this chip has two
> versions now:
> W25Q32BV - 2.7V ~ 3.6V and
> W25Q32DW - 1.7V ~ 1.95V
> I don't think we ever going to see "...DW" chip in PC, but I think it
> is good idea to update Wiki to list the right chip W25Q32BV.

hm yes, that is indeed a minor problem. please note that the voltages
are not used (yet) to change the actual voltage on programmers that
support this feature.

your solution is not convincing though. one problem is, that flashrom
is not only used with PC hardware. another one is that flashrom (and
the wiki) groups chips together that can not be distinguished by any ID
command (yet). it may be possible to distinguished the chips above with
some non-standard and/or extended ID command which has not been
implemented yet - i have not checked that.
in any case it might be a good idea to be able to add footnotes to
chips too and i have put that on my todo list.
the short-term solution would be a comment in flashchips.c on
all/many/some affected chips (at least the whole W25Q series is
probably affected). patches/findings welcome ;)

[Svetoslav Trochev]

Hi Stefan,
> > P.S. I notice that in the WIKI page the Winbond W25Q32 is listed as
> > 2.7V ~ 3.6V chip, but in my search I found out that this chip has two
> > versions now:
> > W25Q32BV - 2.7V ~ 3.6V and
> > W25Q32DW - 1.7V ~ 1.95V
> > I don't think we ever going to see "...DW" chip in PC, but I think it
> > is good idea to update Wiki to list the right chip W25Q32BV.
>
> hm yes, that is indeed a minor problem. please note that the voltages
> are not used (yet) to change the actual voltage on programmers that
> support this feature.

I thought, it would be simple documentation update, but now I
understand it could become a real problem in near future.
> your solution is not convincing though. one problem is, that flashrom
> is not only used with PC hardware. another one is that flashrom (and
> the wiki) groups chips together that can not be distinguished by any ID
> command (yet). it may be possible to distinguished the chips above with
> some non-standard and/or extended ID command which has not been
> implemented yet - i have not checked that.

I see the problem.
> in any case it might be a good idea to be able to add footnotes to
> chips too and i have put that on my todo list.
> the short-term solution would be a comment in flashchips.c on
> all/many/some affected chips (at least the whole W25Q series is
> probably affected). patches/findings welcome ;)

I think you should put your todo item on hold for now. Let me try to
compile flashrom from source and I think this should be very easy
patch for first-timer like me. Let see if I can actually do something
useful.... I mean to create actual patch for flashchips.c.

Thank you,
Svetoslav