Practice Exam 2, Problem 1: Short Questions

Midterm 1 practice exam 2, problem 1 of 5 · Length: 11:27 · Exercises: 20a_asm_bridge (Week 6) · 21r_unsafe_bridge (Week 6) · 30k_kernel_basics (Week 6) · Answer key: Solutions (PDF)

Four parts, worked on the exam's pages 2 to 5: (a) which line of a write_reg test fails to compile, why a checked write needs no unsafe, and what a write past the end of the array does; (b) what an optimizing compiler may do to a UART send loop written with plain accesses, and the volatile rewrite; (c) which compiler message each change to the 30k kernel produces, and why #[no_std] without its ! fails; (d) what happens when bytecopy's extern "C" declaration lists its arguments in the wrong order. The answer key's handwriting is written onto the exam page as each step is worked.

Download the video (MP4, 45 MB) · Captions (WebVTT) · All five problems