Make the compiled ASM binary small?

[junkoi]

Hi,

I am writing some (32bit) ASM code, and compile it with gcc. The output binary is quite big, however. I want to make it as small as possible.

The current gcc options I am using is like:

gcc -nostdlib -fno-builtin -c a.S -o a.bin

And the size of a.bin is around 400 bytes.

I am sure I can reduce the size of a.bin, as the similar code compiled with nasm has the size of only 123 bytes.

Which gcc options should I use now?

Thanks a lot,
J

[junkoi]

I think I found the reason: beside .text section (which is only thing I want), gcc produces some other sections, such as .data, .bss and .shstrtab.
And that makes the final binary bigger.

Now I want gcc not to produce those sections, but only give me .text. Which gcc options should I use?

Thanks,
J

[xenos]

Try -oformat binary to omit string tables and such, and use a linker script if you really want to remove any other section besides .text.