With MKS Toolkit 8.7, why does the lockf() API now fail with error 43? This did not happen with previous versions.

This is new behaviour with large file support in MKS Toolkit 8.7 and it is working as intended. There is an attempt to lock a file beyond the 2G boundary when using lockf().

You can ignore this by using a _NuTConf() and return to the previous behaviour.

#include

_NutConf(_NC_SET_FULL_LFS_SEMANTICS, 0);