Secondary interrupts v/s primary interrupts

Hi folks/members from Ti,

                                         why dont you give a simple differentiation between secondary and primary interrupts. kind of major differences in terms of following

1. how map them to ISRs() in terms of APIs to use, whether it is event EventCombiner_dispatchPlug or hwiIsrmap().

2. secondary or primary are they DEDICATEDLY/FIXEDLY mapped to event ids.

3. should primary can also be mapped to any event id.

4. what is the difference between GEM Interrupt, VectId and eventId

5. what is the difference between system interrupts and host interrupts. 

6. any major difference between primary/secondary interrupts destined to COREPAC and TPCC0/1/Hyperlink/2 in handling?

rather than providing lengthy paragraphs [i seriously see the way documents are written and the terminologies used in the code and documents], it is better to give a kind of comparison between them.

it all adds up to confusion for end users. why dont Ti clarify on following terminologies in documents

system interrupts

host interrupts

vectids

gem interrupts

eventids

eventcombiners in .cfg files.

Thanks

RC Reddy