[Pgubook-readers] [Chapter 4] what is "Old %ebp" for and what is it?

[김태윤]

hello
I am reading programming from the ground up chapter 4, 40page
there is stack figuration which is
Parameter #N
...
Parameter 2
Parameter 1
Return Address
Old %ebp
Local Variable 1
Local Variable 2

I have no idea what "Old %ebp" for.
if %ebp is used for accessing return address and parameters, then why
don't %ebp point just return address rather than "Old %ebp"?
is it for future uses?

my question is this
Q1. what is "Old %ebp" for and what is it?
Q2. why %ebp point Old %ebp not just return address?