The Linux Edge (1999)

A serious effort to make the Linux kernel code portable began with the effort to port Linux to DEC’s Alpha machine. The first port came from a team who ported the Linux kernel to the Motorola 68K series, which was the chip in the early Sun, Apple, and Amiga computers. The Linux kernel memory management could be written to a common denominator among these architectures, and then it would not be so hard to modify the memory management code for the details of a specific architecture.

Source: blog.corememory.io