effect of pointer size on code segment size

English Programming/Scripting
1

Hello

Please explain how pointer size affects code segment size. (Redirections to
references are welcome.)

Thank you.

2

You’re reading that 8086/80286 book aren’t you. :slight_smile:

But forgetting the abomination that x86 segment registers are, the width of pointers affects the size of the data area that is accessible to a program. So a 32-bit pointer can address up to 4GB of memory.

PS: That’s not the same thing as what the OS can use. With hardware extensions like PAE, the OS can manage a much larger arena of memory. This is per-program.

3

ken yap wrote:

>
> You’re reading that 8086/80286 book aren’t you. :slight_smile:
>
> But forgetting the abomination that x86 segment registers are, the
> width of pointers affects the size of the data area that is accessible
> to a program. So a 32-bit pointer can address up to 4GB of memory.
>
> PS: That’s not the same thing as what the OS can use. With hardware
> extensions like PAE, the OS can manage a much larger arena of memory.
> This is per-program.
>
Thank you for the clarification. I am reading the book Deep C Secrets by
Peter van Linden.