BaseFlash simulation driver

[faisal]

Here's a simulation driver for a BaseFlash. It uses a file on disk as the backing store.

One cool feature is that it supports a memory mapped mode as well - caching the file in RAM, and using the base address of the cache as the .address in the flash_descriptor. Downside is that it allocates enough memory to cache the entire simulated flash, and refreshes it on every erase/program operation. This is relatively cheap for small flash sizes, but can become prohibitive for large ones. An improvement would be to mmap() the file with PROT_READ (anyone wanna contribute this?)

I've tested this with the MFS test suite, and and other custom higher level libraries that use BaseFlash objects.

[faisal]

Here's one that specific for EFL - which can be added to os/hal/ports/simulator/posix. It's very similar. A notable difference is that this has a flash_descriptor_t that is defined in the LLD driver itself (configurable via preprocessor symbols) - as opposed to the generic driver above which expects a ptr to a flash_descriptor_t as part of the configuration.

[Giovanni]

Moving to change request.

Giovanni