module uos: Some file operations fail:

[robert-hh]

This is about the /flash file system:
uos.getcwd(): returns "/flash/flash" instead "/flash"
uos.stat("./boot.py"):

>>> os.stat("./boot.py")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: [Errno 2] ENOENT

Version:
MicroPython v0.2.4 on 2019-04-05; Sipeed_M1 with kendryte-k210
Type "help()" for more information.

[robert-hh]

The error with os.getcwd() can be fixed by changing line 331 of file vsf_spiffs.c into:
return mp_obj_new_str("", 0);
The SD card behavior is not affected.
Fixing the other limitations in the chosen SPIFFS implementation may be wast of time. Using a better SPIFFS package is a better choice.