operating systems xv6

Midterm topics: - C code - Manipulate arrays (like integer arrays) - Manipulate strings (character arrays) with string functions, and without functions - Work with argc and argv - Open, read, write, close files - Read input from keyboard - Processes (ch 4 & 5): - Fix broken code that does a fork/exec/wait pattern (perhaps missing some steps) - Explain a zombie is made, and how it is avoided - How to make a process execute two different kinds of code (e.g., some code that computes numbers, other code that interacts with user). - How to run another program (like the shell does) - Answer questions about a process state table like Figure 4.4 in Ch 4 in OSTEP book - Time-sharing, "limited direct execution" (ch 6; stop at page 9): - Explain difference between user mode and kernel mode, and how to switch from user to kernel - Identify which "ring" goes with which mode - Explain purpose of "trap table", and when it is created and by what (answer: OS) - Explain a figure like 6.2 (ch 6 in OSTEP), ignoring "kernel stack" parts - How process switching works: given a story, explain if it's a "cooperative" approach or "non-cooperative" approach - Explain how non-cooperative mode works exam is 40 minutes 11 am newyork time text me WhatsApp 0 0 9 6 6 5 4 5 5 2 5 8 6 1