Other than the obvious case of incorrect arguments being sent to a kernel API call, two types of errors may occur while running REXIS:
Kernel operation failure. The kernel may encounter
an out of memory error, or other unexpected condition. If possible,
the kernel will call the function rexis_UserSyscallError to report the error.
2. Unexpected error conditions. The kernel may detect an unexpected error condition such as the stack value of a task is out of range, indicating possible memory corruption. If possible, the kernel will call the function rexis_UserSOS to report the error.
Neither of these errors should occur in a production system. The only recourse is to reset the system, which is catastrophic by itself. As a user, it behooves you to test your firmware as much as possible to eliminate any errors from occurring.