[meta-freescale] [PATCH 0/1] arm: imx: fsl_otp: make fuses (OTP memory) read-only

Alexander Holler holler at ahsoftware.de
Thu Nov 13 11:19:49 PST 2014


Am 10.11.2014 um 15:11 schrieb Alexander Holler:
> Am 08.11.2014 22:54, schrieb Robin Findley:
>>  From Alexander Holler
>>> But there is absolutely no reason to include this ONE TIME FUNCTIONALITY
>>> into any kernel meant for the public, especially as it is very
>>> dangerous.
>>
>> The problem isn't that someone can burn fuses in a commercial product.
>> Rather, the problem is a designer who ships a product with unburned
>> fuses.  If
>> a designer is unaware of the fuses, and ships them unburned (unless he
>> has
>> good reason), then he shouldn't be selling commercial products.  You
>> can't
>> design an imx product without knowing about the fuses.  They are
>> fundamental
>> to the design process.
>
> You're only talking about locked products which are including the SW, do
> you?
>
> What's if the software isn't part of you manufacturing process and you
> want to leave the customer the choice to enter secure mode whenever he
> wish?
>
> Setting and locking fuses means removing options and crippling the HW.
> That's their only purpose.

And because I've just got reminded to that fact by some other device:

There are many devices which don't ship at first with security mode 
enabled but where the manufacturer intends to use security mode with a 
later update of the firmware. So even if the user-visible software is 
already part of a device, there are reasons to not disable options by 
locking the fuses.

Regards,

Alexander Holler


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