arch linux gcc 32-bit libraries c assembly
- 07 Nov 2017: Post was created (diff)
I wanted to compile my C code with gcc -m32 so I could easily follow old C and assembly tutorials, but it required 32-bit gcc libraries which are not available by default in an Arch Linux installation.
From the ArchWiki:
To use the multilib repository, uncomment the [multilib] section in /etc/pacman.conf (Please be sure to uncomment both lines):
After editing my /etc/pacman.conf, I ran pacman -Syu to update the (not yet cached) package list from the multilib repository. Then I installed the package I needed.
# pacman -S lib32-gcc-libs
Now I can compile my C code for 32-bit machines
$ gcc -fverbose-asm -g -m32 -O0 -o $dest -c $src
To get the assembly code for the produced object file with Intel notation:
$ objdump -dS -M intel $dest
Disassembly of section .text:
00000000 <main>:
#include <stdio.h>
int main(void)
{
0: 8d 4c 24 04 lea ecx,[esp+0x4]
4: 83 e4 f0 and esp,0xfffffff0
7: ff 71 fc push DWORD PTR [ecx-0x4]
a: 55 push ebp
b: 89 e5 mov ebp,esp
d: 53 push ebx
e: 51 push ecx
f: 83 ec 10 sub esp,0x10
12: e8 fc ff ff ff call 13 <main+0x13>
17: 05 01 00 00 00 add eax,0x1
int i = 1;
1c: c7 45 f4 01 00 00 00 mov DWORD PTR [ebp-0xc],0x1
printf("%i\n", i);
23: 83 ec 08 sub esp,0x8
26: ff 75 f4 push DWORD PTR [ebp-0xc]
29: 8d 90 00 00 00 00 lea edx,[eax+0x0]
2f: 52 push edx
30: 89 c3 mov ebx,eax
32: e8 fc ff ff ff call 33 <main+0x33>
37: 83 c4 10 add esp,0x10
return 0;
3a: b8 00 00 00 00 mov eax,0x0
}
3f: 8d 65 f8 lea esp,[ebp-0x8]
42: 59 pop ecx
43: 5b pop ebx
44: 5d pop ebp
45: 8d 61 fc lea esp,[ecx-0x4]
48: c3 ret
References
- https://stackoverflow.com/q/1289881/90674
- https://stackoverflow.com/q/8021874/90674
If you have any comments or feedback, please send me an e-mail. (stig at stigok dotcom).
Did you find any typos, incorrect information, or have something to add? Then please propose a change to this post.