9 - x86 Flags and Stacks Flashcards
1
Q
What are EGLAGS ?
A
They’re the CPU status flags which record information on conditions such as overflow or carry.
2
Q
Which flags are most commonly used?
A
- S = sign (to tell if operation result is negative)
- Z = whether zero or not
- C = carry (arithmetic carry)
- O = overflow (arithmetic)
3
Q
What is a stack?
A
A memory arrangement (data structure) for storing and retrieving information (values).
Like a stack of coins, one on top of another. When we add a value, it goes on top, and the stack grows.
Conversely, when we remove a value, it’s taken from the top and the stack decreases.
LIFO = ‘Last in, first out’
