[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 07:06:24 PST 2014

On Fri, Nov 7, 2014 at 12:40 PM, Alexander Holler <holler at ahsoftware.de> wrote:
> Am 07.11.2014 um 12:34 schrieb Otavio Salvador:
>> 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?
> No.
> Sorry but I really think such dangerous stuff never should make it's way
> into any kernel which doesn't have big red and yellow signs attached to
> it. And unfortunately that isn't possible.
> And even if it would be possible to mark kernels as dangerous, I think
> that functionality should only be part of a bootloader where it isn't
> reachable by normal userspace.

Ok so I am here Nacking your patch.

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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