xv6 a simple, Unix-like teaching operating system Russ Cox Frans Kaashoek Robert Morris xv6-book@pdos.csail.mit.edu Draft as of September 3, 2014 Contents 0 Operating system interfaces 7 1 Operating system organization 17 2 Page tables 29 3 Traps, interrupts, and drivers 37 4 Locking 49 5 Scheduling 57 6 File system 71 7 Summary 87 A PC hardware 89 B The boot loader 93 Index 99 DRAFT as of Septemb