[flashrom] Where is read lock typically implemented?

[Stefan Tauner]

On Tue, 5 Aug 2014 15:41:03 -0400
TR Reardon <thomas_reardon at hotmail.com> wrote:

> Got it, thanks all for the quick responses.
> 
> I take it that read-protection of non-described areas (ie where there
> are gaps in the described regions) is done _implicitly_ by the ICH SPI
> controller?

exactly. all addresses that are not described in the descriptor are
implicitly read-/write-protected. IIRC this is not documented in any
public intel datasheet

> In the case of Winbond 25Q64 chips, I saw only write-protection in the
> datasheet, no chip-level read-protection.

Yes, read protections are not that common (yet) for basic flash chips.
The are very common where companies think they have to hide their data
and/or algorithms (FPGA code, industrial/automotive microcontrollers),
and X86 is moving towards this area pretty fast right now. :(

-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner