[yocto] VFAT patent EP 0 618 540

[Chris Simmonds]

Hi

On 10/10/15 17:58, Robert Berger wrote:
> Hi
>
> On 10/09/2015 11:20 PM, Ayoub Zaki wrote:
>> TI Socs Boot Rom code can use Vfat but does not necessarly need it as
>> Bootloaders (spl, u-boot) can be loaded directly  from Raw MMC/eMMC.
> I just discovered this recently. Something like:
>
> sudo dd if=./u-boot/MLO of=${DISK} count=1 seek=1 bs=128k
> sudo dd if=./u-boot/u-boot.img of=${DISK} count=2 seek=1 bs=384k
>
> So even my made up scenario where you would need vfat on the first
> partition does not hold anymore.
Usually the need to include vfat support driven by the desire to
read/write removable media such as SD cards and USB mass storage
devices. If you want interoperability with certain legacy operating
systems vfat is the only option.

>
> ... but ...
>
> what about the patent and the on-chip ROMs of SoCs from Ti and Freescale
> (hmm NXP? or whoever bought them lately). Maybe the SoCs are affected
> since they are able to load stuff from vfat, even if we don't need to
> use this feature anymore.
Not a problem for two reasons. First the patent only applies to fat32;
you can do anything you like with fat16. The TI romcode only uses fat16,
I am pretty sure. Second, even with fat32, the patent is only concerned
with updates to the namespace, hence so long as the romcode does not
have the ability to create files it is also OK. Note that you can't get
round the patent just by mounting vfat partitions read-only because the
driver still has the ability to make new files. There was a patch for
the vfat driver which removed the code to create or modify directory
entries, but it seems to have got lost in the mists of time.
>
> Regards,
>
> Robert
>
> ..."Never express yourself more clearly than you think." - Niels Bohr
>
> My public pgp key is available,at:
> http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x90320BF1
>
>
-- 
Chris Simmonds, Consultant, 2net Ltd
http://www.2net.co.uk
+44 (0)1962 869003