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92 |
C code:
int MyFunction(int argWord, int word2)
{
int x = 9;
int y = 5;
...
...
...
return localWord;
}
Stack Memory Address
| |0xffe8
------------------
sp ->| 5 |0xffea
------------------
| 9 |0xffec
------------------
| Saved Bp |0xffee
------------------
bp ->| Return adddress |0xfff0
------------------
| argWord |0xfff2
------------------
| word2 |0xfff4
------------------
8086 architecture. Stack will grow to lower addresses
Now let's change the code a little:
C code:
int MyFunction(int argWord, int word2)
{
int y = 22;
int *x = &y;
...
...
...
return localWord;
}
Stack Memory Address
| |0xffe8
------------------
sp ->| 0xffec |0xffea
------------------
| 22 |0xffec
------------------
| Saved Bp |0xffee
------------------
bp ->| Return adddress |0xfff0
------------------
| argWord |0xfff2
------------------
| word2 |0xfff4
------------------
Now if I do this:
*x = 12;
the value of y changes to 12 and the stack looks like this:
then the stack changes
Stack Memory Address
| |0xffe8
------------------
sp ->| 0xffec |0xffea
------------------
| 12 |0xffec
------------------
| Saved Bp |0xffee
------------------
bp ->| Return adddress |0xfff0
------------------
| argWord |0xfff2
------------------
| word2 |0xfff4
------------------ |