GNU as a.k.a. Gas

My first assembly program ..
Ah it sux, but demonstrating how to use Gas, gdb etc. with a program which is too simple, anyone would understand..

varmathe@opensuse103-vm:/temp/varmathe> cat test.S
/*
* First gas assembly program by Varghese Mathew !
* simply to add two numbers on the x86
* Purpose: demonstrate the usage of gas, gdb etc
*/

.global main     /* define the main to be callable from libc */
     .text    /* text segment */
main:            /* the prodigal main function */
     movl $100, %eax     # load 100 in eax
     movl $200, %ebx     # load 200 in ebc
     addl %eax, %ebx     # add the two and store in ebx

/* the end */

varmathe@opensuse103-vm:/temp/varmathe>   
varmathe@opensuse103-vm:/temp/varmathe>
varmathe@opensuse103-vm:/temp/varmathe> gcc -g test.S
varmathe@opensuse103-vm:/temp/varmathe>
varmathe@opensuse103-vm:/temp/varmathe> gdb a.out
GNU gdb 6.6.50.20070726-cvs
Copyright (C) 2007 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i586-suse-linux"...
Using host libthread_db library "/lib/libthread_db.so.1".
(gdb)
(gdb) break main
Breakpoint 1 at 0x8048394: file test.S, line 10.
(gdb) run
Starting program: /temp/varmathe/a.out

Breakpoint 1, main () at test.S:10
10              movl $100, %eax     # load 100 in eax
Current language:  auto; currently asm
(gdb) info registers
eax            0x1      1
ecx            0xbfa61264       -1079635356
edx            0xbfa61200       -1079635456
ebx            0xb7edbff4       -1209155596
esp            0xbfa611dc       0xbfa611dc
ebp            0xbfa61238       0xbfa61238
esi            0xb7f25ca0       -1208853344
edi            0x0      0
eip            0x8048394        0x8048394 

eflags         0x200246 [ PF ZF IF ID ]
cs             0x73     115
ss             0x7b     123
ds             0x7b     123
es             0x7b     123
fs             0x0      0
gs             0x33     51
(gdb) info reg eax
eax            0x1      1
(gdb) info reg ebx
ebx            0xb7edbff4       -1209155596
(gdb) n
11              movl $200, %ebx     # load 200 in ebc
(gdb) info reg eax
eax            0x64     100
(gdb) info reg ebx
ebx            0xb7edbff4       -1209155596
(gdb) n
12              addl %eax, %ebx     # add the two and store in ebx
(gdb) info reg eax
eax            0x64     100
(gdb) info reg ebx
ebx            0xc8     200
(gdb) n
0x080483a0 in __libc_csu_fini ()
(gdb) info reg eax
eax            0x64     100
(gdb) info reg ebx
ebx            0x12c    300
(gdb) c
Continuing.

Program exited with code 0144.
(gdb) q
varmathe@opensuse103-vm:/temp/varmathe>

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