When developing software to run in a Unix environment, you will often be able to use the same system features and benefit from good developer tools, regardless of the particular platform you're working on, as most processors will provide a rich instruction set and virtual memory, among other things. When you're on the other side of the fence, and working in the kernel, all the gory details which will heavily differ across platforms can no longer be ignored, and sometimes, the shortcomings of a given processor architecture can become a real pain in the arse. For example, if you have read the m88k saga , you might remember that the need, for the operating system exception handler, to perform all the pending load and stores before returning from exception processing, had been a source of problems for years. The 88100 processor is not the only processor which sometimes makes the kernel developer's life harder than it could have been.…