[flashrom] Trouble disabling write-protection on Chromebook

[David Hendricks]

On Tue, Jan 14, 2014 at 8:23 AM, Cory Henderson <dcoryh192 at gmail.com> wrote:

> With the chromebook powered on (be careful), and your multimeter in DC
> volt mode, touch one probe to any metallic part of the computer chassis or
> any known ground (could even use the ground pin of the flash), then touch
> the other probe to the /WP pin (there was a datasheet sent out before with
> pictures of all of the different packages and their pinouts). If your meter
> reads 0V then the pin is being pulled down and the hardware /WP is being
> enforced. If it reads 1.8V or something around there then it might be a bad
> chip or something off in flashrom.
>

Yep, that's exactly right.

For reference, here is the datasheet link posted earlier:
http://www.winbond-usa.com/hq/enu/ProductAndSales/ProductLines/FlashMemory/SerialFlash/W25Q32DW.htm
.
The chip layout is on page 6--We're using the SOIC 208-mil package. The
black dot which indicates pin 1 corresponds with a small dimple on the chip
itself (and perhaps a white dot silkscreened on the mainboard PCB).

IIRC this system is using the 1.8V chip, but it could be 3.3V. The
procedure Cory outlined is correct, in either case.

-- 
David Hendricks (dhendrix)
Systems Software Engineer, Google Inc.
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