[meta-freescale] [PATCH 1/1] arm: imx: fsl_otp: make fuses (OTP memory) read-only

Otavio Salvador otavio at ossystems.com.br
Fri Nov 7 03:34:11 PST 2014

On Fri, Nov 7, 2014 at 7:43 AM, Alexander Holler <holler at ahsoftware.de> wrote:
> Nothing in userspace should be able to kill the HW.
> Not even just as root and for sure not that easy.
> For obvious reason, I haven't tested this patch thoroughly.
> Reported-by: Jon Nettleton <jon.nettleton at gmail.com>
> Signed-off-by: Alexander Holler <holler at ahsoftware.de>

I have a mix of feelings about the patch.

Long story, short:

 - We ought to have a FSL_OTP_WRITE_SUPPORT config option

The writing support is specially useful for manufacturing images where
we can use Linux to do the initial programing, consult a database to
find out inventory information (MAC address for example) and do proper
programing on the OTP fuses. However I also believe we shouldn't have
this available on regular kernel images as it is easy to get a
'expensive paper weight'.

So would you be keen to rework the patch and include a write support
config option?

Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750

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