Using Config Flash from ZPUino

[thefloe]

Hi,

 

I know that in general the configuration memory of FPGAs can be accessed and used with some limitations. And as the ZPUino loads it's program from the FLASH I would be very interested to know if it's possible to store and read some values from the sketch?

 

Thanks,

Tobias

[alvieboy]

Not sure exacly whay you mean by reading and writing values. Indeed you have access to the whole of the SPI flash, if that is what you ask for.

 

If you only need reading, you can find "smallfs" useful. It will store a bunch of files in flash easily accessible using open/fopen and similar means. Just place all files inside a folder named "smallfs" in your sketch and use SmallFS library or open/read/so on.

 

For more advanced uses, you can:

 

a) access the end of used flash from within ZPUino. That will tell you what you can or not use.

Use SPI communication to flash in order to read and erase/write what you want.

 

Best,

Alvie

[thefloe]

Thank you Alvie. Sorry for not making my self clear. 

 

In the meantime I managed to access the config memory and I wrote a small library that can read and write bytes from it. Data are stored in the last sector of the memory.

 

Hope this can help someone else...

PFlash.zip

[Jack Gassett]

Hey cool, I'd love to add this library to DesignLab. I put it on my task list, or maybe you wouldn't mind forking DesignLab_Examples putting it under the libraries folder and then doing a pull request?

 

Thanks!

Jack.

[thefloe]

done

[Jack Gassett]

Thank you! Now we just need to make an example.