It's less than you would think. Despite having offerings in about every IP block segment about the only ARM IP blocks that get heavy use are the pieces that have some other ecosystem thing going on. PL011 uarts are de facto required for some initial consoles. Mali GPUs were being sold in what was frankly a move that needed some anti-trust scrutiny (ARM saw Apple taking the piss out of IMG and decided to go in for the kill by offering CPUs+GPU for cheaper than CPUs on their own, overnight destroying IMG's market). Beyond that it's easier to not pay ARM for their IP. NoC fabrics and IP blocks that touch pads are better coming relatively straight from the foundry. Simple serial controllers are essentially commodities at this point. Etc.
So RISC-V really only needs to focus on CPU cores to be an existential threat to ARM.
At this point their biggest most is probably the patents on AMBA specs, but if they tried hard to enforce those the industry would switch to something like TileLink in a relative heartbeat.
So RISC-V really only needs to focus on CPU cores to be an existential threat to ARM.
At this point their biggest most is probably the patents on AMBA specs, but if they tried hard to enforce those the industry would switch to something like TileLink in a relative heartbeat.