Mercurial > hg > index.cgi

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Object Files</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="LW Tool Chain"
HREF="index.html"><LINK
REL="UP"
TITLE="Output Formats"
HREF="c21.html"><LINK
REL="PREVIOUS"
TITLE="OS9 Modules"
HREF="x46.html"><LINK
REL="NEXT"
TITLE="LWASM"
HREF="c62.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"
>LW Tool Chain</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="x46.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 2. Output Formats</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="c62.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECTION"
><H1
CLASS="SECTION"
><A
NAME="AEN54"
>2.7. Object Files</A
></H1
><P
>LWASM supports generating a proprietary object file format which is
described in <A
HREF="c1085.html"
>Chapter 6</A
>. LWLINK is then used to link these
object files into a final binary in any of LWLINK's supported binary
formats.</P
><P
>Object files also support the concept of sections which are not valid
for other output types. This allows related code from each object file
linked to be collapsed together in the final binary.</P
><P
>Object files are very flexible in that they allow references that are not
known at assembly time to be resolved at link time.  However, because the
addresses of such references are not known at assembly time, there is no way
for the assembler to deduce that an eight bit addressing mode is possible.
That means the assember will default to using sixteen bit addressing
whenever an external or cross-section reference is used.</P
><P
>As of LWASM 2.4, it is possible to force direct page addressing for an
external reference.  Care must be taken to ensure the resulting addresses
are really in the direct page since the linker does not know what the direct
page is supposed to be and does not emit errors for byte overflows.</P
><P
>It is also possible to use external references in an eight bit immediate
mode instruction.  In this case, only the low order eight bits will be used.
Again, no byte overflows will be flagged.</P
></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="x46.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="c62.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>OS9 Modules</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="c21.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>LWASM</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
author	William Astle <lost@l-w.ca>
date	Tue, 13 Apr 2021 15:38:12 -0600
parents	52af0aa54fe5
children	543b5d1341d2