Re: [PATCH v2 1/3] Revert "mtd: spi-nor: remove Fujitsu MB85RS1MT support"

[Richard Weinberger]

----- Ursprüngliche Mail -----
> Von: "Chris Packham" <Chris.Packham@xxxxxxxxxxxxxxxxxxx>
>>> On Wed, 2026-07-01 at 09:49 +0000, Takahiro.Kuwano@xxxxxxxxxxxx wrote:
>>>> I didn't mean any kernel features, but we can dump tmpfs contents
>>>> from/to FRAM chip (exposed as NVMEM device) by 'dd'. Doesn't it meet
>>>> your system's requirement?
>>> Do you mean something like creating a tmpfs and then say, using `tar`
>>> and copying the data to nvmem with dd and restoring this data at boot?
>> Yes, I meant something like that (sorry, my comment was still not clear).
>> Hope that's worth considering.
> 
> It won't quite work. Because we have requirements involving ensuring
> when a file is erased it is gone ASAP (i.e. shred). It's all a bit of
> security theater because in reality the safest thing would be to keep
> such secrets in a TPM or protected with a key stored in a TPM.

Do you really need (POSIX) file system semantics?
You could partition the FRAM into cells and then work with them.
e.g. Just dd into it and erase it when needed...
Maybe the NVMEM cells mechanism needs some polishing but this sounds
reasonable to me.

Thanks,
//richard