This is reasonable and correct. I would also have found places in that map for: dcache, block devices, character devices, scheduler, page cache and console/tty/pty. The first two replace "filesystem hierarchy". The second and third are ancient and fundamental classes of UNIX devices.
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I think it needs three areas, not two:
1. User space
2. Kernel
3. Hardware/network
The kernel protects users from hardware, and hardware from users.
This is reasonable and correct. I would also have found places in that map for: dcache, block devices, character devices, scheduler, page cache and console/tty/pty. The first two replace "filesystem hierarchy". The second and third are ancient and fundamental classes of UNIX devices.
this is analagous to the fs hierarchy: root protects from the user