lolevel

boot & entry

entry.S, start.c, main.c — power-on to scheduler()

14 drills TRAIN →

traps & interrupts

trampoline.S, kernelvec.S, trap.c

13 drills TRAIN →

system calls

syscall.c, sysproc.c, usys.pl — ecall to dispatch

8 drills TRAIN →

virtual memory

vm.c, kalloc.c — page tables & the allocator

12 drills TRAIN →

exec

exec.c — ELF loading & the argv stack

8 drills TRAIN →

scheduling & context switch

proc.c, swtch.S

12 drills TRAIN →

pipes & file descriptors

pipe.c, file.c — producer/consumer & the fd layer

8 drills TRAIN →

file system

bio.c, log.c, fs.c

12 drills TRAIN →

console & uart

console.c, uart.c — a real device driver

8 drills TRAIN →

locking

spinlock.c, sleeplock.c

9 drills TRAIN →

boot & startup

privilege modes, mret, the path to main()

20 questions STUDY →

processes & scheduling

process states, context switches, sleep/wakeup

15 questions STUDY →

virtual memory

Sv39 page tables, mappings, page faults

16 questions STUDY →

traps & interrupts

system calls, the trampoline, devices

16 questions STUDY →

file system

inodes, logging, the buffer cache

15 questions STUDY →

locking

races, spinlocks, deadlock ordering

14 questions STUDY →

risc-v assembly

registers, pseudo-instructions, CSRs — read the kernel's .S files

12 questions STUDY →

bits, bytes & addresses

hex, masks, alignment — the arithmetic behind PTEs & bitmaps

12 questions STUDY →

calling conventions & stack frames

frames, caller/callee-saved, overflows — why swtch & trapframes look that way

12 questions STUDY →

compilation, linking & loading

sections, symbols, ELF — kernel.ld & end[] explained

12 questions STUDY →

pipelining

stages, hazards, forwarding

12 questions STUDY →

caches & memory hierarchy

locality, associativity, miss penalties

12 questions STUDY →

isa design tradeoffs

RISC vs CISC, encodings, calling conventions

12 questions STUDY →