The architects of MIT's 6.828 course "Operating Systems Engineering") were unsatisfied with the current stable of systems for teaching, so they did a reimplementation of 6th Edition in modern ANSI C (with a couple of GNU extensions for things like assigning names to registers) targeting a multiprocessor x86. As I look it, it is a clean interesting, and accessible piece of work. As the person that mentioned it to be said: "a modern take on a classic" - the course if being offered this fall at the URL: 6.828 / Fall 2014 <http://pdos.csail.mit.edu/6.828/2014/xv6.html> The latest xv6 source is available via git clone git://pdos.csail.mit.edu/xv6/xv6.git <http://git//pdos.csail.mit.edu/xv6/xv6.git> Tools are can be found at: 6.828 / Fall 2014 <http://pdos.csail.mit.edu/6.828/2014/tools.html> Using the MIT course or the Lion's text will teach how the kernel works and how a user program interacts with it. IMO: Lion's commentary is super and 100% of the source is there to read and ponder. Please remember that generations of the best kernel hackers started with this document (although some of us predate it - but when I saw it I made a copy). And as I said, I just looked at the MIT documents and they are awesome too; but I have just opened them up and have not yet gotten a chance to try the exercises. What is even cooler is if you want to try xv6 - it will just run on your system using QEMU (which the MIT folks point too - they even made some mods to QEMU to help with their project). ᐧ On Thu, Jan 10, 2019 at 10:00 AM David &lt;david(a)kdbarto.org&gt; wrote:

On Thu, Jan 10, 2019 at 10:00 AM David &lt;david(a)kdbarto.org&gt; wrote: I'm a kernel engineer, but I don't have much of a formal background in computer science; my training was in mathematics. However, I audited the MIT OS course about a year ago (my office is across the street from campus and Robert Morris and Adam Belay were kind enough to let me sit in on the class and pester them with questions). They used JOS, which has a fairly unique architecture, and xv6, which is a "modern" re-implementation of most of v6. I've seen some universities try to cover Linux (I believe my alma mater, Columbia, does this), and I imagine that what that means is that they talk about various subsystems at a relatively high level and give some very focused programming assignments. In the 90s there was a flurry of "teaching" operating systems. Things like NACHOS and some successor systems were popular. I suspect Minix remains popular in some circles, though I don't know. I remember once in the 90s talking to some sysadmins; one of the Unix guys got talking to the local VMS guru (who, by the way, was an amazingly talented programmer--probably one of the best I've ever seen before or since). They got to arguing about the merits of the respective systems and the Unix guy incredulously said, "Unix is the textbook operating system..." to which the VMS guy replied, "yeah, because the textbook was written about Unix...". That's kind of a true statement and has always sort of stuck with me. The systems that influence me personally the most in my day-to-day work are plan9, Unix, VMS (also in its other guise as Windows), Akaros, and to a lesser extent L4, Multics, TOPS-20 and Minix. - Dan C.