3 ms·

Without raw memory access, good luck supporting anything than basic hardware. Even some USB features requires it.

• msla 7y ago
  It's entirely possible to write a system where application code only gets sanitized handles and OS code inside the implementation gets raw memory pointers at least some of the time. All running in one address space doesn't mean all running in one security context, necessarily. Really, address spaces are just a hardware implementation of a more general concept: Namespace-based security. Application code wouldn't even be able to know the names of privileged objects, and if someone told that code the right names, it wouldn't be able to use them, because resolution of names to things is, itself, privileged. In a simple example, assuming a Common Lisp-like system: Everything which handles raw pointers is in the SYSTEM package. Application code can't inspect the SYSTEM package, and, even if you told an application that the function SYSTEM:WRITE-DATA-TO-DISK was a thing, it couldn't call that function because the real evaluation code, which can see into the SYSTEM namespace, knows not to let application code call anything in SYSTEM; only the functions in SYSTEM and SYSCALL can do that.