I think pictures tell a big story. That is way I made a series of linux nasm tutorials on my youtube channel.

For video tutorials, check out http://www.youtube.com/soliduscode.

Not to be self-serving, I think it explains in great details what assembly is, the stack frame, and how certain assembly instructions work.

MOV AX,@DATA
MOV DS,AX

LEA DX,MSG
MOV AH,9
INT 21H

MOV AH ,4CH
INT 21H

MAIN ENDP
END MAIN

i have used ubuntu 11.04

sorry my english is not good but i hope you can understand.

That is crazy.

section .data
hello: db ‘Hello world!’,10 ; ‘Hello world!’ plus a linefeed character
helloLen: equ $-hello ; Length of the ‘Hello world!’ string
; (I’ll explain soon)

section .text
global _start

_start:
mov eax,4 ; The system call for write (sys_write)
mov ebx,1 ; File descriptor 1 – standard output
mov ecx,hello ; Put the offset of hello in ecx
mov edx,helloLen ; helloLen is a constant, so we don’t need to say
; mov edx,[helloLen] to get it’s actual value
int 80h ; Call the kernel

mov eax,1 ; The system call for exit (sys_exit)
mov ebx,0 ; Exit with return code of 0 (no error)
int 80h

jay@aerial-link:~$ sudo vim hello.asm
jay@aerial-link:~$ nasm -f elf hello.asm
hello.asm:2: error: expression syntax error

what should i do?

even though i tried to run then it diaplayed….

segmentation fault

first think of a command line

printf “Hello World” > /dev/stdout

there are 6 registers

eax contains the pointer for what kernel system call
ebx first argument
ecx 2nd argument
edx 3rd argument
esx 4th argument
edi 5th argument

int 80h tells the kernel to run the stack

mov eax, 4

The above command will put 4 into eax register, which is the function
it is sys_write

mov eax,4 – tells kernel function sys_write
mov ebx,1 – this is stdout – if you know nix based systems, 2 is stderr
mov ecx,hello – pointer to string
mov edx,helloLen – pointer to length
int 80h – tell kernel to run stack
mov eax,1 – tells kernel function sys_exit
mov ebx,0 – tell it to return 0, like c++
int 80h – tell kernel to run stack

so on a standard command line (bash for example) would look like

printf “${variable:0:$length}” > /dev/stdout

sys_write “string” >/dev/stdout

instead of going from left to right, it goes down, like japeneese

If you have more questions, please email me at staxjp [AT] gmail.com

To learn more about system calls, or kernel handler go to google and type “Linux System Call Table”

I resolved the problem. It was a syntax related. Thank you very much for setting up this site for Assembly programmers.
Please let me know if I can help.

Regards,
Mike

I keep getting error on the second line of your sample code?
Is this an actual working code? do you have one?

Regards,
Mike

http://www.linuxasmbly.org
http://www.members.save-net.com/jko%40save-net.com/asm/

I work on the latter site and it is growing very fast.

jeff

especially for the interrupt and service settings.

Programming Assembly in Linux is different with in MS-DOS. In Linux you deal with a kernel meanwhile in DOS you deal with DOS services.
There few books and websites describe about Assembly programming in Linux. You can use Google by typing “NASM”.

sounds interesting…..
I have knowledge in C and I am doing now .net programming, is it easy for me to learn assembly?? I am just a college fresh student and computer enthusiast, as you have said you can easily go with every port of the machine, and want to learn about that…
can you list some nice resources for assembly?

thanks…..:)