[flashrom] W25Q64 write protect range cleared on reboot (Acer C720): Feature or bug?

David Hendricks dhendrix at google.com
Wed Aug 31 23:09:00 CEST 2016

Hi Brishchik,
This is actually the management engine at play and is a known issue.

You'll have to ask Intel about this logic to judge whether it's a feature
or a bug...

On Wed, Aug 31, 2016 at 7:49 AM, Brishchik Gupta <brishchik at mail.com> wrote:

> Device: Acer C720-3605 Chromebook (Haswell) with Winbond W25Q64 8MB
> firmware flash
> Description of issue --- The following behavior is observed:
> 1. If write protect is disabled (either in hardware i.e. screw removed, or
> in software i.e. status.srp0 == 0 == status.srp1, or in both hardware and
> software) AND there is a non-null write protect range (set by status
> register bits BP0/BP1/BP2/TB/SEC), then upon power cycled reboot, the
> status registers get completely cleared (to 0x0000).
> 2. If write protect is disabled in hardware but not in software and the
> write protect range is null (so status registers == 0x0080), then a power
> cycled reboot preserves the status registers (i.e. the value is still
> 0x0080 after reboot).
> Is the above behavior a feature or a bug?
> I can post logs (e.g. outputs of "flashrom --wp-status") if necessary.
> Best regards,
> Brishchik Gupta
> _______________________________________________
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> flashrom at flashrom.org
> https://www.flashrom.org/mailman/listinfo/flashrom

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