TouchGFX using FileSystem on QSPI

[LGall]

Hello,

I am evaluating TouchGFX and I read this :

examples of memory types that are not memory mapped and thus require caching

• All NAND-based flashes
• SD cards
• Anything with a file system
• QuadSPI NOR if your microcontroller does not include memory-mapping for it (e.g. STM32F429)

So TouchGFX Highly recommand to use QSPI in memory map mode and no filesystem.

But, what about if I have a filesystem on QSPI configured as memory map mode (read-only) ?

It is still recommanded to cache all images inside my filesystem on QSPI even in memory map mode but with filesystem ?

Thanks !

[Martin KJELDSEN]

Hi @LGall​,

The reason we recommend some sort of external memory (memory mapped preferrable), Is because most complex applications demand a lot of storage for images and texts (depending on the formats, RGB565 vs RGB888, etc.). But, this may be different depending on your application.

As long as the assets are accessible from your QSPI flash in a binary format you are fine. The application won't be able to read assets from your filesystem because it basically just reads an amount of memory from a certain address (specified in your linker script).

Does that make sense?

/Martin

[LGall]

Hello,

Thanks for your answer.

You said : "The application won't be able to read assets from your filesystem because it basically just reads an amount of memory from a certain address (specified in your linker script)."

If I understand well, TouchGFX can not read image file drectly from FileSystem and need to precach all images before ?

Am I rights ?

Logan

[Martin KJELDSEN]

Hi Logan,

That's correct. If no memory-mapped memory is available, all images must be cached and loaded from that cache. Would you be able to reserve a portion of your QSPI for assets in their binary form instead of storing them as files on the file system itself?

/Martin

[LGall]

Hello Martin,

Thanks again for your answer. We would like to use FileSystem to be able to change dynamically images that can be displayed.

Maybe the best solution is to use our own light FS with rawData use in Memory map mode ?