Function Call Convention (TGPD: The GLADOS Project Documentation)

Calling sequence:

1. Push function address
2. Execute CALL
   → Saves (PC+1, SP) to call stack
   → Jumps to function

Return sequence:

1. Execute RET
   → Restores PC and SP
   → Trims stack to SP position
   → If call stack empty: program terminates

Stack frame layout:

┌──────────────────┐
│  Caller frame    │
├──────────────────┤  ← SP
│  Local function  │  ← Stack top
└──────────────────┘