<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML ><HEAD ><TITLE >Introduction</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Linux Assembly HOWTO" HREF="index.html"><LINK REL="UP" TITLE="Quick start" HREF="quickstart.html"><LINK REL="PREVIOUS" TITLE="Quick start" HREF="quickstart.html"><LINK REL="NEXT" TITLE="Hello, world!" HREF="hello.html"></HEAD ><BODY CLASS="SECTION" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Linux Assembly HOWTO</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="quickstart.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 6. Quick start</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="hello.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECTION" ><H1 CLASS="SECTION" ><A NAME="AEN825" ></A >6.1. Introduction</H1 ><P >Finally, if you still want to try this crazy idea and write something in assembly (if you've reached this section -- you're real assembly fan), here's what you need to start.</P ><P >As you've read before, you can write for Linux in different ways; I'll show how to use <EM >direct</EM > kernel calls, since this is the fastest way to call kernel service; our code is not linked to any library, does not use ELF interpreter, it communicates with kernel directly.</P ><P >I will show the same sample program in two assemblers, <B CLASS="COMMAND" >nasm</B > and <B CLASS="COMMAND" >gas</B >, thus showing Intel and AT&T syntax.</P ><P >You may also want to read <A HREF="http://linuxassembly.org/intro.html" TARGET="_top" >Introduction to UNIX assembly programming</A > tutorial, it contains sample code for other UNIX-like OSes.</P ><P ></P ><DIV CLASS="SECTION" ><H2 CLASS="SECTION" ><A NAME="AEN836" ></A >6.1.1. Tools you need</H2 ><P >First of all you need assembler (compiler) -- <B CLASS="COMMAND" >nasm</B > or <B CLASS="COMMAND" >gas</B >.</P ><P >Second, you need a linker -- <B CLASS="COMMAND" >ld</B >, since assembler produces only object code. Almost all distributions have <SPAN CLASS="APPLICATION" >gas</SPAN > and <SPAN CLASS="APPLICATION" >ld</SPAN >, in the binutils package.</P ><P >As for <SPAN CLASS="APPLICATION" >nasm</SPAN >, you may have to download and install binary packages for Linux and docs from the <A HREF="nasm.html#P-NASM-WHERE" >nasm site</A >; note that several distributions (Stampede, Debian, SuSe, Mandrake) already have <SPAN CLASS="APPLICATION" >nasm</SPAN >, check first.</P ><P >If you're going to dig in, you should also install include files for your OS, and if possible, kernel source.</P ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="quickstart.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="hello.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Quick start</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="quickstart.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Hello, world!</TD ></TR ></TABLE ></DIV ></BODY ></HTML >
