STM32 W25Qxx LittleFS
While working on STM32 W25Qxx I briefly experimented with getting FATFS up and running on the flash device. I quickly realised that this is a really poor idea. The problem is that W25Qxx flash devices has got a limited number of writes. FATFS works on some fixed tables and these tables will be updated on each file write. A typical W25Qxx got a number of guaranteed writes around 100000. If you imagine a system that update a file every second, this could mean that sector will wear out in < 2 days.
A much better approach is to use a file system with built-in wear levelling and fortunately LittleFS is just that.