"In the case of CHERI, this was to change the user-visible abstract machine exposed by hardware in a way that hasn’t been done for mainstream hardware since the PDP-11." - the authors should take the time to familiarise themselves with the Burroughs B6700 (designed in the 1960s) which provided tagged memory, and a similar mechanism to CHERI architectural capabilities through the B6700 descriptor mechanism.
The PDP-11 minicomputer was a low-cost and undoubtably successful for its time system but a low bar for architectural sophistication or an exemplar for state of the art in computer architecture particularly in terms of memory design.
CHERI is a welcome development in producing safer systems, but it is packaging ideas that have been around for 50+ years, long overdue of course, but finally hardware costs have commoditised such that these ideas can be baked into mass produced hardware.
CHERI is a welcome development in producing safer systems, but it is packaging ideas that have been around for 50+ years, long overdue of course, but finally hardware costs have commoditised such that these ideas can be baked into mass produced hardware.