Help: Some rtems basic questions... sorry...

[Alex]

Hi all, 
I am a beginner in the rtems kernell... I have reading some documents but I cant 
solution some doubts:
My doubts are:Does RTEMS has user space and kernell space?
Does RTEMS suppoorts more than one process running at a time?
Does RTEMS has memory protection? virtual address partitions?
Does rtems supports interrupt nesting...?
Sorry about this simple questions, but I cant have sure about this?

Any special document to read? Any advices?

Am trying the BSP for i686


Many thanks

Alex