CS208 Introduction to Computer Systems
Friday, 3 Feb 2023

+ Two goals [8:30]
- walk through the assembly version of function-calling
- demonstrate getting started on the bomb-defusing assignment

+ functions.c [8:31]
- what it does
- why we're looking at it

+ The system stack [8:34]
- what's a "stack frame"?
- what goes in a stack frame?
- rsp
- rbp?

+ Addressing modes [8:37]
https://web.stanford.edu/class/archive/cs/cs107/cs107.1224/guide/x86-64.html#addressing-modes
- register
    just the name of a register
    MOV rdi, rax

- immediate
    a literal number
    MOV 0x23, rax

- direct
    address is specified as a literal
    JNE    0x555555555200

- indirect
- indirect with displacement
    Contents of the specified register,
        add to displacement, use the result
        as an address. Go to that address
        and get what you find there.
    mov    0x8(%rsi),%rdi 

- indirect with displacement and scaled index

+ Walk through functions.c, C mode [8:42]
- run/r
- break/br
- next/n
- step/s
- print
- info reg/i r

+ Walk through functions.c, asm mode [8:52]
- Keep track of the stack frames
- Keep track of rsp
- Keep track of rip

+ Looking at the bombs assignment [9:10]
- How to get your bomb
- What to do with it
- Sample bomb, etc.