Stack Frame: push, pop, rbp, rsp

The Stack Grows Down

Each call pushes a return address; each function builds a frame below that. rsp points at the stack top; rbp anchors locals at fixed negative offsets. GDB backtraces, stack overflows, and ROP gadgets all read this layout.

nasmCopy
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• Locals live at [rbp-8], [rbp-16], etc.
• leave is shorthand for mov rsp, rbp; pop rbp
• System V requires rsp % 16 == 0 before another call for SSE

Interactive Visualization

Step through nested calls and watch rbp chain to older frames:

For this exercise, you will write functions with a standard prologue/epilogue and address locals through rbp. This task asks you to maintain 16-byte alignment across calls, because misaligned stacks surface as mysterious crashes inside libc printf on the next call.

Keep the relevant man page, ABI doc, or Rust reference chapter open while you work. When your output disagrees with the reference implementation on the same machine, the mismatch is usually an alignment rule, an off-by-one terminator, or a register slot you misread in GDB. Skim the official documentation for the tool or ABI named in the exercise; the prose changes, but register roles, syscall numbers, and ownership rules stay stable across releases.