Deep dive into the stack ...

qqion1988

1. What is the correspondence between stack segments and stacks?
A 64K stack segment corresponds to a 64K stack. Is this true? Or can a 64K stack segment correspond to multiple smaller stacks?
2. So how to address the stack through SS: SP?
3. What is the relationship between the stack segment base address and the top and bottom of the stack?

kaishiba

Generally speaking, if it is not initialized, ss is loaded into the base address of the stack segment, and sp is initialized to point to the end of the segment minus one byte. At this time, the end of the segment is the bottom of the stack, and the byte pointed to by sp For the top of the stack.
Personally inferred, I also want to know the specific implementation methods of various compilers

amiu888

Personal understanding:
A stack segment corresponds to a stack, and a task has only one stack segment at the same time.
SS stores the selector of the stack segment. The selector specifies the length of the stack, the growth direction and the limit length. SP stores the bottom of the stack segment. At the beginning, the bottom address <= top address, if there is no data in the stack, then the bottom address = top address, otherwise the bottom <top address

qqion1988

After a night of thought and reference, the problem was finally solved ...

> 1. What is the correspondence between stack segment and stack?
A 64K stack segment corresponds to a 64K stack, is this the case? Or is a 64K stack segment corresponding to multiple stacks smaller than it?

The stack segment corresponds exactly to the stack, and the size of the stack and the stack segment are equal.

> 2. So how to address the stack through SS: SP?

SS * 16 + SP

> 3. What is the relationship between the base address of the stack segment and the top and bottom of the stack?

The base address obtained after SS * 16 is the top of the stack, and SP points to the bottom of the stack.

                     Thanks:
Thank youkaishibaandamiu888friends for their enthusiastic participation.

amiu888

Your understanding is in real mode. In protected mode, you need to use selectors.