Arm RDP and RDI history

[metebalci]

I am trying to find some information about RDP and RDI used for semihosting. Arm has some documentation regarding semihosting and Angel SWI but not much (and I cannot find application note 39: Demon and RDP). My understanding is:

- Demon SWI, Demon monitor, RDP and rdpmon are related to the same concept or protocol
- Angel SWI, Angel monitor, ADP, RDI and rdimon are related to the same concept or protocol

I see almost only RDI at the moment, is Demon/RDP the old way/not-supported anymore ?