QSPI XIP with TouchGFX

[ikendal]

Our STM32L4S7 project is consuming internal flash much faster than we expected despite the fact that we've taken steps to move as many assets into external flash as we can, including SVG images.

Our next approach is to see if we can split the TouchGFX code between internal and external flash and rely on XIP to run some of it.  I've run some small XIP tests on our board with success so we know it's possible in theory.

My primary question is what would be the best way to split the TouchGfx code between internal and external flash? I'm familiar with the linker script so I know how to place the modules, but I'm wondering which modules to put in external flash. Is TouchGFX designed in such a way to make this feasible?

[Tesla DeLorean]

The STM32L4S7 doesn't provide for caching, so external memory is going to be measurably slower. I guess you might want to profile what's used a lot, vs what is used less frequently and use that to weight what goes where. Static images you'd probably want to always park in external memory.