Drivers for KBE and Flash

Where can I find the driver source code of the keyboard emulator? I have some sporadic issues and want to investigate and try to find the root cause.
in addition the flash - SPI module where can i find it’s drivers source code?

There is tiny file system from @ taylorza on codeshare for the flash module.

thanks,
are there also the drivers of the KBE?

Please check the documentation, it has an example for KBE:

https://www.ghielectronics.com/downloads/man/Library_Documentation_v4.1/html/c606ac5c-a84e-26e3-5be8-ae035fe6eda8.htm