[Gnuk-users] Making use of FST-01 SPI flash in Gnuk token

[Duncan]

Hello Mr. Niibe,

Thank you for your helpful and considered reply.

However, I think I was not very clear in my intent. While it would be 
nice if the firmware were able to make use of the flash, I am wondering 
how one can allow the host computer to access the flash, like a mass 
storage device.

For instance, I would like to be able to plug in my FST-01 device into 
my laptop computer, and then have a mass storage device appear, on which 
I could deposit files of my choosing. I don't really mind about the 
speed, considering the space is constrained in the first place.

However, from your email it appears that this is not implemented 
properly yet, and it sounds like it wouldn't be a priority, for 
understandable reasons.

I'm sorry if I wasn't very clear.

Thank you,
Duncan

On 09.01.2018 22:21, NIIBE Yutaka wrote:
> Duncan <dguthrie at posteo.net> wrote:
>> As I understand it, the devices sold via Seeed Studio Bazaar had the
>> link to the documentation on this flash.
>> 
>> This strikes me as a useful thing. I'd like to accomplish the 
>> following:
>> 
>> 1. Build the latest Gnuk token firmware
>> 2. Install my public key and miscellaneous other data onto the SPI 
>> flash.
>> 3. Expand the size of the flash (I am thinking this might not be
>> possible, from glancing over certain datasheets).
>> 
>> In the original firmware, how did the flash appear? I assume it had a
>> filesystem on it, probably vFAT? If so, can we make use of a different
>> filesystem, just out of interest?
> 
> No, the flash is not used at all by the firmware (Gnuk).  We only have 
> a
> little access code for that in gnuk/tool/stlinkv2.py.  That's all.
> 
> From hardware point of view (wa have space on PCB), I put the serial
> flash to FST-01, hoping it will be useful.  But, I was not able to find
> any useful way, in fact.
> 
> In FST-01G (I manufactured last year), I drooped the serial flash (as
> the part is not available any more).
> 
> Expanding the firmware, it would be somehow possible to give the access
> to the serial flash through USB Mass Storage Class to users, but it 
> will
> be slow, given the condition of available memory size of STM32F103.
> 
> If we do by USB Mass Storage Class, file system handling is done by 
> host
> PC.