page table:

A UNIX legacy, the "u." or per-process data structure, which held the kernel-related data of a process, was present on 386BSD prior to February 1991.

The 386 Paging Memory Management allocates memory in 4KB and 4MB allocation units. This impacts the way programs execute and share file data.

386BSD started out in 1989 with a derivative virtual memory system from the VAX by way of a 68030. In February/March 1991, it was cutover to a totally different one cut out of CMU's MACH system, and released with Net/2.

This article, last of the original three done altogether in 1990, on getting the critical pieces functioning independantly that we needed to do the port. Once these we obtained, the kernel was inevitable.

We initialized the processor with initial descriptor and page tables - one needs to run with the tables before activating memory/interrupt kernel functions.

We coded trap handlers and simulated read and write faults to test out page faults with our processor support code. On a 2MB machine, we knew we'd get 1,000's.