Re: Buffers in Assembly (NASM)

On Fri, 18 Jul 2008 19:34:08 -0700 (PDT), "bwaichu@xxxxxxxxx"
<spamtrap@xxxxxxxxxx> wrote:

I'm trying to better understand data structures in assembly. I know I
can create a zero filled buffer in the bss section in NASM with this:

The bss section is by definition not initialized by the program, so
you have to clear it yourself.

buffer: times 64 db 0
This should get an error in the bss section.


And I know I can create a buffer on the stack like this:

sub esp, 64
mov ebx, esp ;save the start point of the buffer

But how do I zero out the buffer on the stack? In C, I would just do
something like:

char buffer[64] = {0};
Which does what I show below.


What's the equivalent in assembly using NASM?

This will work for either the stack, or bss: (baring typos)
xor al,al
mov ecx,64
lea edi,buffer ; may need [] ?
rep stosb

OR:
xor eax,eax
mov ecx,16
lea edi,buffer ; may need [] ?
rep stosd
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