The original Linux kernel used the task switching primitives included in the 80386 machine language. The tasks in the OS were directly mapped to 80386 tasks a

The original Linux kernel used the task switching primitives included in the 80386 machine language. The tasks in the OS were directly mapped to 80386 tasks and task table entries, so the kernel was heavily tied to the 386 architecture. Linus himself once posted to USENet that it was unlikely Linux would ever run on anything but the 386 and its successors. Happily, he did the work to make himself wrong.