Mercurial > hg > index.cgi
changeset 236:ce1fdc8d6568
Added ability to add padding after a section when linking.
Added the ability for lwlink to automatically append padding bytes to the
end of a section (once the section instances are merged). This behaviour is
controlled by the link script. See the updated documentation for more
information.
| author | William Astle <lost@l-w.ca> |
|---|---|
| date | Sat, 11 Aug 2012 23:29:57 -0600 |
| parents | e3741cf53e00 |
| children | d4cf2e139e4a |
| files | docs/manual.docbook.sgml docs/manual/c858.html docs/manual/c867.html docs/manual/c920.html docs/manual/c929.html docs/manual/index.html docs/manual/manual.html docs/manual/manual.pdf docs/manual/x37.html docs/manual/x795.html docs/manual/x843.html docs/manual/x852.html lwlink/link.c lwlink/lwlink.h lwlink/main.c lwlink/readfiles.c lwlink/script.c |
| diffstat | 17 files changed, 1168 insertions(+), 897 deletions(-) [+] |
line wrap: on
line diff
--- a/docs/manual.docbook.sgml Sat Aug 11 15:18:58 2012 -0600 +++ b/docs/manual.docbook.sgml Sat Aug 11 23:29:57 2012 -0600 @@ -1984,6 +1984,30 @@ <variablelist> <varlistentry> +<term>sectopt <parameter>section</parameter> padafter <parameter>byte,...</parameter></term> +<listitem> + +<para> + +This will cause the linker to append the specified list of byte values +(specified in hexadecimal separated by commas) to the end of the named +section. This is done once all instances of the specified section are +collected together. This has no effect if the specified section does not +appear anywhere in any of the objects specified for linking. + +</para> + +<para> + +If code depends on the presence of this padding somewhere, it is sufficient +to include an empty section of the specified name in the object that depends +on it. + +</para> + +</listitem> + +<varlistentry> <term>define basesympat <parameter>string</parameter></term> <listitem> @@ -1996,6 +2020,18 @@ section have been collapsed together. </para> + +<para> + +It should be noted that if none of the objects to be linked contains a +particular section name, there will be no base symbol defined for it, even +if it is listed explicitly in the link script. If code depends on the +presence of these symbols, it is sufficient to include an empty section of +the specified name in the object that depends on it. + +</para> + + <para> If the pattern resolves to the same string for multiple sections, the results are undefined. @@ -2015,6 +2051,18 @@ collapsed together. </para> + +<para> + +It should be noted that if none of the objects to be linked contains a +particular section name, there will be no length symbol defined for it, even +if it is listed explicitly in the link script. If code depends on the +presence of these symbols, it is sufficient to include an empty section of +the specified name in the object that depends on it. + +</para> + + <para> If the pattern resolves to the same string for multiple sections, the results are undefined.
--- a/docs/manual/c858.html Sat Aug 11 15:18:58 2012 -0600 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,270 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> -<HTML -><HEAD -><TITLE ->Libraries and LWAR</TITLE -><META -NAME="GENERATOR" -CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK -REL="HOME" -TITLE="LW Tool Chain" -HREF="index.html"><LINK -REL="PREVIOUS" -TITLE="Format Specific Linking Notes" -HREF="x843.html"><LINK -REL="NEXT" -TITLE="Object Files" -HREF="c920.html"></HEAD -><BODY -CLASS="CHAPTER" -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="x843.html" -ACCESSKEY="P" ->Prev</A -></TD -><TD -WIDTH="80%" -ALIGN="center" -VALIGN="bottom" -></TD -><TD -WIDTH="10%" -ALIGN="right" -VALIGN="bottom" -><A -HREF="c920.html" -ACCESSKEY="N" ->Next</A -></TD -></TR -></TABLE -><HR -ALIGN="LEFT" -WIDTH="100%"></DIV -><DIV -CLASS="CHAPTER" -><H1 -><A -NAME="AEN858" -></A ->Chapter 5. Libraries and LWAR</H1 -><P ->LWTOOLS also includes a tool for managing libraries. These are analogous to -the static libraries created with the "ar" tool on POSIX systems. Each library -file contains one or more object files. The linker will treat the object -files within a library as though they had been specified individually on -the command line except when resolving external references. External references -are looked up first within the object files within the library and then, if -not found, the usual lookup based on the order the files are specified on -the command line occurs.</P -><P ->The tool for creating these libary files is called LWAR.</P -><DIV -CLASS="SECTION" -><H1 -CLASS="SECTION" -><A -NAME="AEN862" ->5.1. Command Line Options</A -></H1 -><P ->The binary for LWAR is called "lwar". Note that the binary is in lower -case. The options lwar understands are listed below. For archive manipulation -options, the first non-option argument is the name of the archive. All other -non-option arguments are the names of files to operate on.</P -><P -></P -><DIV -CLASS="VARIABLELIST" -><DL -><DT -><CODE -CLASS="OPTION" ->--add</CODE ->, <CODE -CLASS="OPTION" ->-a</CODE -></DT -><DD -><P ->This option specifies that an archive is going to have files added to it. -If the archive does not already exist, it is created. New files are added -to the end of the archive.</P -></DD -><DT -><CODE -CLASS="OPTION" ->--create</CODE ->, <CODE -CLASS="OPTION" ->-c</CODE -></DT -><DD -><P ->This option specifies that an archive is going to be created and have files -added to it. If the archive already exists, it is truncated.</P -></DD -><DT -><CODE -CLASS="OPTION" ->--merge</CODE ->, <CODE -CLASS="OPTION" ->-m</CODE -></DT -><DD -><P ->If specified, any files specified to be added to an archive will be checked -to see if they are archives themselves. If so, their constituent members are -added to the archive. This is useful for avoiding archives containing archives.</P -></DD -><DT -><CODE -CLASS="OPTION" ->--list</CODE ->, <CODE -CLASS="OPTION" ->-l</CODE -></DT -><DD -><P ->This will display a list of the files contained in the archive.</P -></DD -><DT -><CODE -CLASS="OPTION" ->--debug</CODE ->, <CODE -CLASS="OPTION" ->-d</CODE -></DT -><DD -><P ->This option increases the debugging level. It is only useful for LWTOOLS -developers.</P -></DD -><DT -><CODE -CLASS="OPTION" ->--help</CODE ->, <CODE -CLASS="OPTION" ->-?</CODE -></DT -><DD -><P ->This provides a listing of command line options and a brief description -of each.</P -></DD -><DT -><CODE -CLASS="OPTION" ->--usage</CODE -></DT -><DD -><P ->This will display a usage summary -of each command line option.</P -></DD -><DT -><CODE -CLASS="OPTION" ->--version</CODE ->, <CODE -CLASS="OPTION" ->-V</CODE -></DT -><DD -><P ->This will display the version of LWLINK. -of each.</P -></DD -></DL -></DIV -></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="x843.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="c920.html" -ACCESSKEY="N" ->Next</A -></TD -></TR -><TR -><TD -WIDTH="33%" -ALIGN="left" -VALIGN="top" ->Format Specific Linking Notes</TD -><TD -WIDTH="34%" -ALIGN="center" -VALIGN="top" -> </TD -><TD -WIDTH="33%" -ALIGN="right" -VALIGN="top" ->Object Files</TD -></TR -></TABLE -></DIV -></BODY -></HTML -> \ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/docs/manual/c867.html Sat Aug 11 23:29:57 2012 -0600 @@ -0,0 +1,270 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> +<HTML +><HEAD +><TITLE +>Libraries and LWAR</TITLE +><META +NAME="GENERATOR" +CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK +REL="HOME" +TITLE="LW Tool Chain" +HREF="index.html"><LINK +REL="PREVIOUS" +TITLE="Format Specific Linking Notes" +HREF="x852.html"><LINK +REL="NEXT" +TITLE="Object Files" +HREF="c929.html"></HEAD +><BODY +CLASS="CHAPTER" +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="x852.html" +ACCESSKEY="P" +>Prev</A +></TD +><TD +WIDTH="80%" +ALIGN="center" +VALIGN="bottom" +></TD +><TD +WIDTH="10%" +ALIGN="right" +VALIGN="bottom" +><A +HREF="c929.html" +ACCESSKEY="N" +>Next</A +></TD +></TR +></TABLE +><HR +ALIGN="LEFT" +WIDTH="100%"></DIV +><DIV +CLASS="CHAPTER" +><H1 +><A +NAME="AEN867" +></A +>Chapter 5. Libraries and LWAR</H1 +><P +>LWTOOLS also includes a tool for managing libraries. These are analogous to +the static libraries created with the "ar" tool on POSIX systems. Each library +file contains one or more object files. The linker will treat the object +files within a library as though they had been specified individually on +the command line except when resolving external references. External references +are looked up first within the object files within the library and then, if +not found, the usual lookup based on the order the files are specified on +the command line occurs.</P +><P +>The tool for creating these libary files is called LWAR.</P +><DIV +CLASS="SECTION" +><H1 +CLASS="SECTION" +><A +NAME="AEN871" +>5.1. Command Line Options</A +></H1 +><P +>The binary for LWAR is called "lwar". Note that the binary is in lower +case. The options lwar understands are listed below. For archive manipulation +options, the first non-option argument is the name of the archive. All other +non-option arguments are the names of files to operate on.</P +><P +></P +><DIV +CLASS="VARIABLELIST" +><DL +><DT +><CODE +CLASS="OPTION" +>--add</CODE +>, <CODE +CLASS="OPTION" +>-a</CODE +></DT +><DD +><P +>This option specifies that an archive is going to have files added to it. +If the archive does not already exist, it is created. New files are added +to the end of the archive.</P +></DD +><DT +><CODE +CLASS="OPTION" +>--create</CODE +>, <CODE +CLASS="OPTION" +>-c</CODE +></DT +><DD +><P +>This option specifies that an archive is going to be created and have files +added to it. If the archive already exists, it is truncated.</P +></DD +><DT +><CODE +CLASS="OPTION" +>--merge</CODE +>, <CODE +CLASS="OPTION" +>-m</CODE +></DT +><DD +><P +>If specified, any files specified to be added to an archive will be checked +to see if they are archives themselves. If so, their constituent members are +added to the archive. This is useful for avoiding archives containing archives.</P +></DD +><DT +><CODE +CLASS="OPTION" +>--list</CODE +>, <CODE +CLASS="OPTION" +>-l</CODE +></DT +><DD +><P +>This will display a list of the files contained in the archive.</P +></DD +><DT +><CODE +CLASS="OPTION" +>--debug</CODE +>, <CODE +CLASS="OPTION" +>-d</CODE +></DT +><DD +><P +>This option increases the debugging level. It is only useful for LWTOOLS +developers.</P +></DD +><DT +><CODE +CLASS="OPTION" +>--help</CODE +>, <CODE +CLASS="OPTION" +>-?</CODE +></DT +><DD +><P +>This provides a listing of command line options and a brief description +of each.</P +></DD +><DT +><CODE +CLASS="OPTION" +>--usage</CODE +></DT +><DD +><P +>This will display a usage summary +of each command line option.</P +></DD +><DT +><CODE +CLASS="OPTION" +>--version</CODE +>, <CODE +CLASS="OPTION" +>-V</CODE +></DT +><DD +><P +>This will display the version of LWLINK. +of each.</P +></DD +></DL +></DIV +></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="x852.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="c929.html" +ACCESSKEY="N" +>Next</A +></TD +></TR +><TR +><TD +WIDTH="33%" +ALIGN="left" +VALIGN="top" +>Format Specific Linking Notes</TD +><TD +WIDTH="34%" +ALIGN="center" +VALIGN="top" +> </TD +><TD +WIDTH="33%" +ALIGN="right" +VALIGN="top" +>Object Files</TD +></TR +></TABLE +></DIV +></BODY +></HTML +> \ No newline at end of file
--- a/docs/manual/c920.html Sat Aug 11 15:18:58 2012 -0600 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,376 +0,0 @@ -<!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="PREVIOUS" -TITLE="Libraries and LWAR" -HREF="c858.html"></HEAD -><BODY -CLASS="CHAPTER" -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="c858.html" -ACCESSKEY="P" ->Prev</A -></TD -><TD -WIDTH="80%" -ALIGN="center" -VALIGN="bottom" -></TD -><TD -WIDTH="10%" -ALIGN="right" -VALIGN="bottom" -> </TD -></TR -></TABLE -><HR -ALIGN="LEFT" -WIDTH="100%"></DIV -><DIV -CLASS="CHAPTER" -><H1 -><A -NAME="OBJCHAP" -></A ->Chapter 6. Object Files</H1 -><P ->LWTOOLS uses a proprietary object file format. It is proprietary in the sense -that it is specific to LWTOOLS, not that it is a hidden format. It would be -hard to keep it hidden in an open source tool chain anyway. This chapter -documents the object file format.</P -><P ->An object file consists of a series of sections each of which contains a -list of exported symbols, a list of incomplete references, and a list of -"local" symbols which may be used in calculating incomplete references. Each -section will obviously also contain the object code.</P -><P ->Exported symbols must be completely resolved to an address within the -section it is exported from. That is, an exported symbol must be a constant -rather than defined in terms of other symbols.</P -><P ->Each object file starts with a magic number and version number. The magic -number is the string "LWOBJ16" for this 16 bit object file format. The only -defined version number is currently 0. Thus, the first 8 bytes of the object -file are <FONT -COLOR="RED" ->4C574F424A313600</FONT -></P -><P ->Each section has the following items in order:</P -><P -></P -><UL -><LI -><P ->section name</P -></LI -><LI -><P ->flags</P -></LI -><LI -><P ->list of local symbols (and addresses within the section)</P -></LI -><LI -><P ->list of exported symbols (and addresses within the section)</P -></LI -><LI -><P ->list of incomplete references along with the expressions to calculate them</P -></LI -><LI -><P ->the actual object code (for non-BSS sections)</P -></LI -></UL -><P ->The section starts with the name of the section with a NUL termination -followed by a series of flag bytes terminated by NUL. There are only two -flag bytes defined. A NUL (0) indicates no more flags and a value of 1 -indicates the section is a BSS section. For a BSS section, no actual -code is included in the object file.</P -><P ->Either a NULL section name or end of file indicate the presence of no more -sections.</P -><P ->Each entry in the exported and local symbols table consists of the symbol -(NUL terminated) followed by two bytes which contain the value in big endian -order. The end of a symbol table is indicated by a NULL symbol name.</P -><P ->Each entry in the incomplete references table consists of an expression -followed by a 16 bit offset where the reference goes. Expressions are -defined as a series of terms up to an "end of expression" term. Each term -consists of a single byte which identifies the type of term (see below) -followed by any data required by the term. Then end of the list is flagged -by a NULL expression (only an end of expression term).</P -><DIV -CLASS="TABLE" -><A -NAME="AEN945" -></A -><P -><B ->Table 6-1. Object File Term Types</B -></P -><TABLE -BORDER="1" -FRAME="border" -CLASS="CALSTABLE" -><COL><COL><THEAD -><TR -><TH ->TERMTYPE</TH -><TH ->Meaning</TH -></TR -></THEAD -><TBODY -><TR -><TD ->00</TD -><TD ->end of expression</TD -></TR -><TR -><TD ->01</TD -><TD ->integer (16 bit in big endian order follows)</TD -></TR -><TR -><TD ->02</TD -><TD -> external symbol reference (NUL terminated symbol name follows)</TD -></TR -><TR -><TD ->03</TD -><TD ->local symbol reference (NUL terminated symbol name follows)</TD -></TR -><TR -><TD ->04</TD -><TD ->operator (1 byte operator number)</TD -></TR -><TR -><TD ->05</TD -><TD ->section base address reference</TD -></TR -><TR -><TD ->FF</TD -><TD ->This term will set flags for the expression. Each one of these terms will set a single flag. All of them should be specified first in an expression. If they are not, the behaviour is undefined. The byte following is the flag. Flag 01 indicates an 8 bit relocation. Flag 02 indicates a zero-width relocation (see the EXTDEP pseudo op in LWASM).</TD -></TR -></TBODY -></TABLE -></DIV -><P ->External references are resolved using other object files while local -references are resolved using the local symbol table(s) from this file. This -allows local symbols that are not exported to have the same names as -exported symbols or external references.</P -><DIV -CLASS="TABLE" -><A -NAME="AEN975" -></A -><P -><B ->Table 6-2. Object File Operator Numbers</B -></P -><TABLE -BORDER="1" -FRAME="border" -CLASS="CALSTABLE" -><COL><COL><THEAD -><TR -><TH ->Number</TH -><TH ->Operator</TH -></TR -></THEAD -><TBODY -><TR -><TD ->01</TD -><TD ->addition (+)</TD -></TR -><TR -><TD ->02</TD -><TD ->subtraction (-)</TD -></TR -><TR -><TD ->03</TD -><TD ->multiplication (*)</TD -></TR -><TR -><TD ->04</TD -><TD ->division (/)</TD -></TR -><TR -><TD ->05</TD -><TD ->modulus (%)</TD -></TR -><TR -><TD ->06</TD -><TD ->integer division (\) (same as division)</TD -></TR -><TR -><TD ->07</TD -><TD ->bitwise and</TD -></TR -><TR -><TD ->08</TD -><TD ->bitwise or</TD -></TR -><TR -><TD ->09</TD -><TD ->bitwise xor</TD -></TR -><TR -><TD ->0A</TD -><TD ->boolean and</TD -></TR -><TR -><TD ->0B</TD -><TD ->boolean or</TD -></TR -><TR -><TD ->0C</TD -><TD ->unary negation, 2's complement (-)</TD -></TR -><TR -><TD ->0D</TD -><TD ->unary 1's complement (^)</TD -></TR -></TBODY -></TABLE -></DIV -><P ->An expression is represented in a postfix manner with both operands for -binary operators preceding the operator and the single operand for unary -operators preceding the operator.</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="c858.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" -> </TD -></TR -><TR -><TD -WIDTH="33%" -ALIGN="left" -VALIGN="top" ->Libraries and LWAR</TD -><TD -WIDTH="34%" -ALIGN="center" -VALIGN="top" -> </TD -><TD -WIDTH="33%" -ALIGN="right" -VALIGN="top" -> </TD -></TR -></TABLE -></DIV -></BODY -></HTML -> \ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/docs/manual/c929.html Sat Aug 11 23:29:57 2012 -0600 @@ -0,0 +1,376 @@ +<!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="PREVIOUS" +TITLE="Libraries and LWAR" +HREF="c867.html"></HEAD +><BODY +CLASS="CHAPTER" +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="c867.html" +ACCESSKEY="P" +>Prev</A +></TD +><TD +WIDTH="80%" +ALIGN="center" +VALIGN="bottom" +></TD +><TD +WIDTH="10%" +ALIGN="right" +VALIGN="bottom" +> </TD +></TR +></TABLE +><HR +ALIGN="LEFT" +WIDTH="100%"></DIV +><DIV +CLASS="CHAPTER" +><H1 +><A +NAME="OBJCHAP" +></A +>Chapter 6. Object Files</H1 +><P +>LWTOOLS uses a proprietary object file format. It is proprietary in the sense +that it is specific to LWTOOLS, not that it is a hidden format. It would be +hard to keep it hidden in an open source tool chain anyway. This chapter +documents the object file format.</P +><P +>An object file consists of a series of sections each of which contains a +list of exported symbols, a list of incomplete references, and a list of +"local" symbols which may be used in calculating incomplete references. Each +section will obviously also contain the object code.</P +><P +>Exported symbols must be completely resolved to an address within the +section it is exported from. That is, an exported symbol must be a constant +rather than defined in terms of other symbols.</P +><P +>Each object file starts with a magic number and version number. The magic +number is the string "LWOBJ16" for this 16 bit object file format. The only +defined version number is currently 0. Thus, the first 8 bytes of the object +file are <FONT +COLOR="RED" +>4C574F424A313600</FONT +></P +><P +>Each section has the following items in order:</P +><P +></P +><UL +><LI +><P +>section name</P +></LI +><LI +><P +>flags</P +></LI +><LI +><P +>list of local symbols (and addresses within the section)</P +></LI +><LI +><P +>list of exported symbols (and addresses within the section)</P +></LI +><LI +><P +>list of incomplete references along with the expressions to calculate them</P +></LI +><LI +><P +>the actual object code (for non-BSS sections)</P +></LI +></UL +><P +>The section starts with the name of the section with a NUL termination +followed by a series of flag bytes terminated by NUL. There are only two +flag bytes defined. A NUL (0) indicates no more flags and a value of 1 +indicates the section is a BSS section. For a BSS section, no actual +code is included in the object file.</P +><P +>Either a NULL section name or end of file indicate the presence of no more +sections.</P +><P +>Each entry in the exported and local symbols table consists of the symbol +(NUL terminated) followed by two bytes which contain the value in big endian +order. The end of a symbol table is indicated by a NULL symbol name.</P +><P +>Each entry in the incomplete references table consists of an expression +followed by a 16 bit offset where the reference goes. Expressions are +defined as a series of terms up to an "end of expression" term. Each term +consists of a single byte which identifies the type of term (see below) +followed by any data required by the term. Then end of the list is flagged +by a NULL expression (only an end of expression term).</P +><DIV +CLASS="TABLE" +><A +NAME="AEN954" +></A +><P +><B +>Table 6-1. Object File Term Types</B +></P +><TABLE +BORDER="1" +FRAME="border" +CLASS="CALSTABLE" +><COL><COL><THEAD +><TR +><TH +>TERMTYPE</TH +><TH +>Meaning</TH +></TR +></THEAD +><TBODY +><TR +><TD +>00</TD +><TD +>end of expression</TD +></TR +><TR +><TD +>01</TD +><TD +>integer (16 bit in big endian order follows)</TD +></TR +><TR +><TD +>02</TD +><TD +> external symbol reference (NUL terminated symbol name follows)</TD +></TR +><TR +><TD +>03</TD +><TD +>local symbol reference (NUL terminated symbol name follows)</TD +></TR +><TR +><TD +>04</TD +><TD +>operator (1 byte operator number)</TD +></TR +><TR +><TD +>05</TD +><TD +>section base address reference</TD +></TR +><TR +><TD +>FF</TD +><TD +>This term will set flags for the expression. Each one of these terms will set a single flag. All of them should be specified first in an expression. If they are not, the behaviour is undefined. The byte following is the flag. Flag 01 indicates an 8 bit relocation. Flag 02 indicates a zero-width relocation (see the EXTDEP pseudo op in LWASM).</TD +></TR +></TBODY +></TABLE +></DIV +><P +>External references are resolved using other object files while local +references are resolved using the local symbol table(s) from this file. This +allows local symbols that are not exported to have the same names as +exported symbols or external references.</P +><DIV +CLASS="TABLE" +><A +NAME="AEN984" +></A +><P +><B +>Table 6-2. Object File Operator Numbers</B +></P +><TABLE +BORDER="1" +FRAME="border" +CLASS="CALSTABLE" +><COL><COL><THEAD +><TR +><TH +>Number</TH +><TH +>Operator</TH +></TR +></THEAD +><TBODY +><TR +><TD +>01</TD +><TD +>addition (+)</TD +></TR +><TR +><TD +>02</TD +><TD +>subtraction (-)</TD +></TR +><TR +><TD +>03</TD +><TD +>multiplication (*)</TD +></TR +><TR +><TD +>04</TD +><TD +>division (/)</TD +></TR +><TR +><TD +>05</TD +><TD +>modulus (%)</TD +></TR +><TR +><TD +>06</TD +><TD +>integer division (\) (same as division)</TD +></TR +><TR +><TD +>07</TD +><TD +>bitwise and</TD +></TR +><TR +><TD +>08</TD +><TD +>bitwise or</TD +></TR +><TR +><TD +>09</TD +><TD +>bitwise xor</TD +></TR +><TR +><TD +>0A</TD +><TD +>boolean and</TD +></TR +><TR +><TD +>0B</TD +><TD +>boolean or</TD +></TR +><TR +><TD +>0C</TD +><TD +>unary negation, 2's complement (-)</TD +></TR +><TR +><TD +>0D</TD +><TD +>unary 1's complement (^)</TD +></TR +></TBODY +></TABLE +></DIV +><P +>An expression is represented in a postfix manner with both operands for +binary operators preceding the operator and the single operand for unary +operators preceding the operator.</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="c867.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" +> </TD +></TR +><TR +><TD +WIDTH="33%" +ALIGN="left" +VALIGN="top" +>Libraries and LWAR</TD +><TD +WIDTH="34%" +ALIGN="center" +VALIGN="top" +> </TD +><TD +WIDTH="33%" +ALIGN="right" +VALIGN="top" +> </TD +></TR +></TABLE +></DIV +></BODY +></HTML +> \ No newline at end of file
--- a/docs/manual/index.html Sat Aug 11 15:18:58 2012 -0600 +++ b/docs/manual/index.html Sat Aug 11 23:29:57 2012 -0600 @@ -201,14 +201,14 @@ ></DT ><DT >4.4. <A -HREF="x843.html" +HREF="x852.html" >Format Specific Linking Notes</A ></DT ><DD ><DL ><DT >4.4.1. <A -HREF="x843.html#AEN846" +HREF="x852.html#AEN855" >OS9 Modules</A ></DT ></DL @@ -217,21 +217,21 @@ ></DD ><DT >5. <A -HREF="c858.html" +HREF="c867.html" >Libraries and LWAR</A ></DT ><DD ><DL ><DT >5.1. <A -HREF="c858.html#AEN862" +HREF="c867.html#AEN871" >Command Line Options</A ></DT ></DL ></DD ><DT >6. <A -HREF="c920.html" +HREF="c929.html" >Object Files</A ></DT ></DL @@ -246,12 +246,12 @@ ></DT ><DT >6-1. <A -HREF="c920.html#AEN945" +HREF="c929.html#AEN954" >Object File Term Types</A ></DT ><DT >6-2. <A -HREF="c920.html#AEN975" +HREF="c929.html#AEN984" >Object File Operator Numbers</A ></DT ></DL
--- a/docs/manual/manual.html Sat Aug 11 15:18:58 2012 -0600 +++ b/docs/manual/manual.html Sat Aug 11 23:29:57 2012 -0600 @@ -198,14 +198,14 @@ ></DT ><DT >4.4. <A -HREF="#AEN843" +HREF="#AEN852" >Format Specific Linking Notes</A ></DT ><DD ><DL ><DT >4.4.1. <A -HREF="#AEN846" +HREF="#AEN855" >OS9 Modules</A ></DT ></DL @@ -214,14 +214,14 @@ ></DD ><DT >5. <A -HREF="#AEN858" +HREF="#AEN867" >Libraries and LWAR</A ></DT ><DD ><DL ><DT >5.1. <A -HREF="#AEN862" +HREF="#AEN871" >Command Line Options</A ></DT ></DL @@ -243,12 +243,12 @@ ></DT ><DT >6-1. <A -HREF="#AEN945" +HREF="#AEN954" >Object File Term Types</A ></DT ><DT >6-2. <A -HREF="#AEN975" +HREF="#AEN984" >Object File Operator Numbers</A ></DT ></DL @@ -2520,6 +2520,26 @@ CLASS="VARIABLELIST" ><DL ><DT +>sectopt <CODE +CLASS="PARAMETER" +>section</CODE +> padafter <CODE +CLASS="PARAMETER" +>byte,...</CODE +></DT +><DD +><P +> This will cause the linker to append the specified list of byte values +(specified in hexadecimal separated by commas) to the end of the named +section. This is done once all instances of the specified section are +collected together. This has no effect if the specified section does not +appear anywhere in any of the objects specified for linking. </P +><P +> If code depends on the presence of this padding somewhere, it is sufficient +to include an empty section of the specified name in the object that depends +on it. </P +></DD +><DT >define basesympat <CODE CLASS="PARAMETER" >string</CODE @@ -2535,6 +2555,12 @@ section name. The base address is calculated after all instances of each section have been collapsed together. </P ><P +> It should be noted that if none of the objects to be linked contains a +particular section name, there will be no base symbol defined for it, even +if it is listed explicitly in the link script. If code depends on the +presence of these symbols, it is sufficient to include an empty section of +the specified name in the object that depends on it. </P +><P > If the pattern resolves to the same string for multiple sections, the results are undefined. </P ></DD @@ -2554,6 +2580,12 @@ name. The length is calculated after all instances of a section have been collapsed together. </P ><P +> It should be noted that if none of the objects to be linked contains a +particular section name, there will be no length symbol defined for it, even +if it is listed explicitly in the link script. If code depends on the +presence of these symbols, it is sufficient to include an empty section of +the specified name in the object that depends on it. </P +><P >If the pattern resolves to the same string for multiple sections, the results are undefined. </P ></DD @@ -2635,7 +2667,7 @@ ><HR><H2 CLASS="SECTION" ><A -NAME="AEN843" +NAME="AEN852" >4.4. Format Specific Linking Notes</A ></H2 ><P @@ -2648,7 +2680,7 @@ ><HR><H3 CLASS="SECTION" ><A -NAME="AEN846" +NAME="AEN855" >4.4.1. OS9 Modules</A ></H3 ><P @@ -2724,7 +2756,7 @@ CLASS="CHAPTER" ><HR><H1 ><A -NAME="AEN858" +NAME="AEN867" ></A >Chapter 5. Libraries and LWAR</H1 ><P @@ -2743,7 +2775,7 @@ ><HR><H2 CLASS="SECTION" ><A -NAME="AEN862" +NAME="AEN871" >5.1. Command Line Options</A ></H2 ><P @@ -2944,7 +2976,7 @@ ><DIV CLASS="TABLE" ><A -NAME="AEN945" +NAME="AEN954" ></A ><P ><B @@ -3016,7 +3048,7 @@ ><DIV CLASS="TABLE" ><A -NAME="AEN975" +NAME="AEN984" ></A ><P ><B
--- a/docs/manual/x37.html Sat Aug 11 15:18:58 2012 -0600 +++ b/docs/manual/x37.html Sat Aug 11 23:29:57 2012 -0600 @@ -79,7 +79,7 @@ ><P >LWASM supports generating a proprietary object file format which is described in <A -HREF="c920.html" +HREF="c929.html" >Chapter 6</A >. LWLINK is then used to link these object files into a final binary in any of LWLINK's supported binary
--- a/docs/manual/x795.html Sat Aug 11 15:18:58 2012 -0600 +++ b/docs/manual/x795.html Sat Aug 11 23:29:57 2012 -0600 @@ -17,7 +17,7 @@ HREF="x781.html"><LINK REL="NEXT" TITLE="Format Specific Linking Notes" -HREF="x843.html"></HEAD +HREF="x852.html"></HEAD ><BODY CLASS="SECTION" BGCOLOR="#FFFFFF" @@ -59,7 +59,7 @@ ALIGN="right" VALIGN="bottom" ><A -HREF="x843.html" +HREF="x852.html" ACCESSKEY="N" >Next</A ></TD @@ -104,6 +104,26 @@ CLASS="VARIABLELIST" ><DL ><DT +>sectopt <CODE +CLASS="PARAMETER" +>section</CODE +> padafter <CODE +CLASS="PARAMETER" +>byte,...</CODE +></DT +><DD +><P +> This will cause the linker to append the specified list of byte values +(specified in hexadecimal separated by commas) to the end of the named +section. This is done once all instances of the specified section are +collected together. This has no effect if the specified section does not +appear anywhere in any of the objects specified for linking. </P +><P +> If code depends on the presence of this padding somewhere, it is sufficient +to include an empty section of the specified name in the object that depends +on it. </P +></DD +><DT >define basesympat <CODE CLASS="PARAMETER" >string</CODE @@ -119,6 +139,12 @@ section name. The base address is calculated after all instances of each section have been collapsed together. </P ><P +> It should be noted that if none of the objects to be linked contains a +particular section name, there will be no base symbol defined for it, even +if it is listed explicitly in the link script. If code depends on the +presence of these symbols, it is sufficient to include an empty section of +the specified name in the object that depends on it. </P +><P > If the pattern resolves to the same string for multiple sections, the results are undefined. </P ></DD @@ -138,6 +164,12 @@ name. The length is calculated after all instances of a section have been collapsed together. </P ><P +> It should be noted that if none of the objects to be linked contains a +particular section name, there will be no length symbol defined for it, even +if it is listed explicitly in the link script. If code depends on the +presence of these symbols, it is sufficient to include an empty section of +the specified name in the object that depends on it. </P +><P >If the pattern resolves to the same string for multiple sections, the results are undefined. </P ></DD @@ -248,7 +280,7 @@ ALIGN="right" VALIGN="top" ><A -HREF="x843.html" +HREF="x852.html" ACCESSKEY="N" >Next</A ></TD
--- a/docs/manual/x843.html Sat Aug 11 15:18:58 2012 -0600 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,224 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> -<HTML -><HEAD -><TITLE ->Format Specific Linking Notes</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="LWLINK" -HREF="c681.html"><LINK -REL="PREVIOUS" -TITLE="Linking Scripts" -HREF="x795.html"><LINK -REL="NEXT" -TITLE="Libraries and LWAR" -HREF="c858.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="x795.html" -ACCESSKEY="P" ->Prev</A -></TD -><TD -WIDTH="80%" -ALIGN="center" -VALIGN="bottom" ->Chapter 4. LWLINK</TD -><TD -WIDTH="10%" -ALIGN="right" -VALIGN="bottom" -><A -HREF="c858.html" -ACCESSKEY="N" ->Next</A -></TD -></TR -></TABLE -><HR -ALIGN="LEFT" -WIDTH="100%"></DIV -><DIV -CLASS="SECTION" -><H1 -CLASS="SECTION" -><A -NAME="AEN843" ->4.4. Format Specific Linking Notes</A -></H1 -><P ->Some formats require special information to be able to generate actual -binaries. If the specific format you are interested in is not listed in -this section, then there is nothing special you need to know about to create -a final binary.</P -><DIV -CLASS="SECTION" -><H2 -CLASS="SECTION" -><A -NAME="AEN846" ->4.4.1. OS9 Modules</A -></H2 -><P ->OS9 modules need to embed several items into the module header. These -items are the type of module, the langauge of the module, the module -attributes, the module revision number, the data size (bss), and the -execution offset. These are all either calculated or default to reasonable -values.</P -><P ->The data size is calcuated as the sum of all sections named "bss" or -".bss" in all object files that are linked together.</P -><P ->The execution offset is calculated from the address of the special -symbol "__start" which must be an exported (external) symbol in one of the -objects to be linked.</P -><P ->The type defaults to "Prgrm" or "Program module". The language -defaults to "Objct" or "6809 object code". Attributes default to enabling -the re-entrant flag. And finally, the revision defaults to zero.</P -><P ->The embedded module name is the output filename. If the output -filename includes more than just the filename, this will probably not be -what you want.</P -><P ->The type, language, attributes, revision, and module name can all be -overridden by providing a special section in exactly one of the object files -to be linked. This section is called "__os9" (note the two underscores). -To override the type, language, attributes, or revision values, define a -non-exported symbol in this section called "type", "lang", "attr", or "rev" -respectively. Any other symbols defined are ignored. To override the -module name, include as the only actual code in the section a NUL terminated -string (the FCN directive is useful for this). If there is no code in the -section or it beings with a NUL, the default name will be used. Any of the -preceeding that are not defined in the special section will retain their -default values.</P -><P ->The built-in link script for OS9 modules will place the following -sections, in order, in the module: "code", ".text", "data", ".data". It -will merge all sections with the name "bss" or ".bss" into the "data" -section. All other section names are ignored. What this means is that you -must define your data variables in the a section called "bss" or ".bss" even -though you will be refencing them all as offsets from U. This does have the -unpleasant side effect that all BSS references will end up being 16 bit -offsets because the assembler cannot know what the offset will be once the -linker is finished its work. Thus, if the tightest possible code is -required, having LWASM directly output the module is a better choice.</P -><P ->While the built-in link script is probably sufficient for most -purposes, you can provide your own script. If you provide a custom link -script, you must start your code and data sections at location 000D to -accommodate the module header. Otherwise, you will have an incorrect -location for the execution offset. You must use the ENTRY directive in the -script to define the entry point for the module.</P -><P ->It should also be obvious from the above that you cannot mix the bss -(rmb) definitions with the module code when linking separately. Those -familiar with typical module creation will probably find this an unpleasant -difference but it is unavoidable.</P -><P ->It should also be noted that direct page references should also be -avoided because you cannot know ahead of time whether the linker is going to -end up putting a particular variable in the first 256 bytes of the module's -data space. If, however, you know for certain you will have less than 256 -bytes of defined data space across all of the object files that will be -linked, you can instead use forced DP addressing for your data addresses -instead of the ,u notation. When linking with 3rd party libraries, this -practice should be avoided. Also, when creating libraries, always use the -offset from U technique.</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="x795.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="c858.html" -ACCESSKEY="N" ->Next</A -></TD -></TR -><TR -><TD -WIDTH="33%" -ALIGN="left" -VALIGN="top" ->Linking Scripts</TD -><TD -WIDTH="34%" -ALIGN="center" -VALIGN="top" -><A -HREF="c681.html" -ACCESSKEY="U" ->Up</A -></TD -><TD -WIDTH="33%" -ALIGN="right" -VALIGN="top" ->Libraries and LWAR</TD -></TR -></TABLE -></DIV -></BODY -></HTML -> \ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/docs/manual/x852.html Sat Aug 11 23:29:57 2012 -0600 @@ -0,0 +1,224 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> +<HTML +><HEAD +><TITLE +>Format Specific Linking Notes</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="LWLINK" +HREF="c681.html"><LINK +REL="PREVIOUS" +TITLE="Linking Scripts" +HREF="x795.html"><LINK +REL="NEXT" +TITLE="Libraries and LWAR" +HREF="c867.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="x795.html" +ACCESSKEY="P" +>Prev</A +></TD +><TD +WIDTH="80%" +ALIGN="center" +VALIGN="bottom" +>Chapter 4. LWLINK</TD +><TD +WIDTH="10%" +ALIGN="right" +VALIGN="bottom" +><A +HREF="c867.html" +ACCESSKEY="N" +>Next</A +></TD +></TR +></TABLE +><HR +ALIGN="LEFT" +WIDTH="100%"></DIV +><DIV +CLASS="SECTION" +><H1 +CLASS="SECTION" +><A +NAME="AEN852" +>4.4. Format Specific Linking Notes</A +></H1 +><P +>Some formats require special information to be able to generate actual +binaries. If the specific format you are interested in is not listed in +this section, then there is nothing special you need to know about to create +a final binary.</P +><DIV +CLASS="SECTION" +><H2 +CLASS="SECTION" +><A +NAME="AEN855" +>4.4.1. OS9 Modules</A +></H2 +><P +>OS9 modules need to embed several items into the module header. These +items are the type of module, the langauge of the module, the module +attributes, the module revision number, the data size (bss), and the +execution offset. These are all either calculated or default to reasonable +values.</P +><P +>The data size is calcuated as the sum of all sections named "bss" or +".bss" in all object files that are linked together.</P +><P +>The execution offset is calculated from the address of the special +symbol "__start" which must be an exported (external) symbol in one of the +objects to be linked.</P +><P +>The type defaults to "Prgrm" or "Program module". The language +defaults to "Objct" or "6809 object code". Attributes default to enabling +the re-entrant flag. And finally, the revision defaults to zero.</P +><P +>The embedded module name is the output filename. If the output +filename includes more than just the filename, this will probably not be +what you want.</P +><P +>The type, language, attributes, revision, and module name can all be +overridden by providing a special section in exactly one of the object files +to be linked. This section is called "__os9" (note the two underscores). +To override the type, language, attributes, or revision values, define a +non-exported symbol in this section called "type", "lang", "attr", or "rev" +respectively. Any other symbols defined are ignored. To override the +module name, include as the only actual code in the section a NUL terminated +string (the FCN directive is useful for this). If there is no code in the +section or it beings with a NUL, the default name will be used. Any of the +preceeding that are not defined in the special section will retain their +default values.</P +><P +>The built-in link script for OS9 modules will place the following +sections, in order, in the module: "code", ".text", "data", ".data". It +will merge all sections with the name "bss" or ".bss" into the "data" +section. All other section names are ignored. What this means is that you +must define your data variables in the a section called "bss" or ".bss" even +though you will be refencing them all as offsets from U. This does have the +unpleasant side effect that all BSS references will end up being 16 bit +offsets because the assembler cannot know what the offset will be once the +linker is finished its work. Thus, if the tightest possible code is +required, having LWASM directly output the module is a better choice.</P +><P +>While the built-in link script is probably sufficient for most +purposes, you can provide your own script. If you provide a custom link +script, you must start your code and data sections at location 000D to +accommodate the module header. Otherwise, you will have an incorrect +location for the execution offset. You must use the ENTRY directive in the +script to define the entry point for the module.</P +><P +>It should also be obvious from the above that you cannot mix the bss +(rmb) definitions with the module code when linking separately. Those +familiar with typical module creation will probably find this an unpleasant +difference but it is unavoidable.</P +><P +>It should also be noted that direct page references should also be +avoided because you cannot know ahead of time whether the linker is going to +end up putting a particular variable in the first 256 bytes of the module's +data space. If, however, you know for certain you will have less than 256 +bytes of defined data space across all of the object files that will be +linked, you can instead use forced DP addressing for your data addresses +instead of the ,u notation. When linking with 3rd party libraries, this +practice should be avoided. Also, when creating libraries, always use the +offset from U technique.</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="x795.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="c867.html" +ACCESSKEY="N" +>Next</A +></TD +></TR +><TR +><TD +WIDTH="33%" +ALIGN="left" +VALIGN="top" +>Linking Scripts</TD +><TD +WIDTH="34%" +ALIGN="center" +VALIGN="top" +><A +HREF="c681.html" +ACCESSKEY="U" +>Up</A +></TD +><TD +WIDTH="33%" +ALIGN="right" +VALIGN="top" +>Libraries and LWAR</TD +></TR +></TABLE +></DIV +></BODY +></HTML +> \ No newline at end of file
--- a/lwlink/link.c Sat Aug 11 15:18:58 2012 -0600 +++ b/lwlink/link.c Sat Aug 11 23:29:57 2012 -0600 @@ -42,10 +42,11 @@ symlist_t *symlist = NULL; +sectopt_t *section_opts = NULL; + void check_section_name(char *name, int *base, fileinfo_t *fn) { int sn; - // fprintf(stderr, "Considering sections in %s (%d) for %s\n", fn -> filename, fn -> forced, name); if (fn -> forced == 0) return; @@ -79,6 +80,7 @@ void check_section_flags(int yesflags, int noflags, int *base, fileinfo_t *fn) { int sn; + sectopt_t *so; // fprintf(stderr, "Considering sections in %s (%d) for %x/%x\n", fn -> filename, fn -> forced, yesflags, noflags); @@ -103,6 +105,20 @@ // we have a match - now collect *all* sections of the same name! // fprintf(stderr, " Found\n"); add_matching_sections((char *)(fn -> sections[sn].name), 0, 0, base); + + /* handle "after padding" */ + for (so = section_opts; so; so = so -> next) + if (!strcmp(so -> name, (char *)(fn -> sections[sn].name))) + break; + if (so) + { + if (so -> aftersize) + { + sectlist[nsects - 1].ptr -> afterbytes = so -> afterbytes; + sectlist[nsects - 1].ptr -> aftersize = so -> aftersize; + *base += so -> aftersize; + } + } // and then continue looking for sections } @@ -146,15 +162,31 @@ { int laddr = 0; int ln, sn, fn; + sectopt_t *so; for (ln = 0; ln < linkscript.nlines; ln++) { if (linkscript.lines[ln].loadat >= 0) laddr = linkscript.lines[ln].loadat; + fprintf(stderr, "Adding section %s\n", linkscript.lines[ln].sectname); add_matching_sections(linkscript.lines[ln].sectname, linkscript.lines[ln].yesflags, linkscript.lines[ln].noflags, &laddr); if (linkscript.lines[ln].sectname) { + char *sname = linkscript.lines[ln].sectname; + /* handle "after padding" */ + for (so = section_opts; so; so = so -> next) + if (!strcmp(so -> name, sname)) + break; + if (so) + { + if (so -> aftersize) + { + sectlist[nsects - 1].ptr -> afterbytes = so -> afterbytes; + sectlist[nsects - 1].ptr -> aftersize = so -> aftersize; + laddr += so -> aftersize; + } + } } else { @@ -184,6 +216,7 @@ if (inputfiles[fn0] -> sections[sn0].processed == 0) { sname = (char *)(inputfiles[fn0] -> sections[sn0].name); + fprintf(stderr, "Adding sectoin %s\n", sname); for (fn = 0; fn < ninputfiles; fn++) { for (sn = 0; sn < inputfiles[fn] -> nsections; sn++) @@ -720,3 +753,22 @@ linkscript.modrev &= 15; linkscript.modattr &= 15; } + +void resolve_padding(void) +{ + int sn; + + for (sn = 0; sn < nsects; sn++) + { + if (sectlist[sn].ptr -> afterbytes) + { + unsigned char *t; + + t = lw_alloc(sectlist[sn].ptr -> codesize + sectlist[sn].ptr -> aftersize); + memmove(t, sectlist[sn].ptr -> code, sectlist[sn].ptr -> codesize); + sectlist[sn].ptr -> code = t; + memmove(sectlist[sn].ptr -> code + sectlist[sn].ptr -> codesize, sectlist[sn].ptr -> afterbytes, sectlist[sn].ptr -> aftersize); + sectlist[sn].ptr -> codesize += sectlist[sn].ptr -> aftersize; + } + } +}
--- a/lwlink/lwlink.h Sat Aug 11 15:18:58 2012 -0600 +++ b/lwlink/lwlink.h Sat Aug 11 23:29:57 2012 -0600 @@ -70,6 +70,9 @@ reloc_t *incompletes; // table of incomplete references fileinfo_t *file; // the file we are in + + int aftersize; // add this many bytes after section on output + unsigned char *afterbytes; // add these bytes after section on output } section_t; struct fileinfo_s @@ -95,9 +98,20 @@ int forceaddr; // was this force to an address by the link script? }; + +typedef struct sectopt_s sectopt_t; +struct sectopt_s +{ + char *name; // section name + int aftersize; // number of bytes to append to section + unsigned char *afterbytes; // the bytes to store after the section + sectopt_t *next; // next section option +}; + #ifndef __link_c_seen__ extern struct section_list *sectlist; extern int nsects; +extern sectopt_t *section_opts; #endif
--- a/lwlink/main.c Sat Aug 11 15:18:58 2012 -0600 +++ b/lwlink/main.c Sat Aug 11 23:29:57 2012 -0600 @@ -167,6 +167,7 @@ extern void resolve_sections(void); extern void generate_symbols(void); extern void resolve_references(void); +extern void resolve_padding(void); extern void do_output(void); extern void display_map(void); @@ -203,6 +204,9 @@ // resolve incomplete references resolve_references(); + + // resolve section padding bits + resolve_padding(); // do the actual output do_output();
--- a/lwlink/readfiles.c Sat Aug 11 15:18:58 2012 -0600 +++ b/lwlink/readfiles.c Sat Aug 11 23:29:57 2012 -0600 @@ -198,6 +198,8 @@ s -> incompletes = NULL; s -> processed = 0; s -> file = fn; + s -> afterbytes = NULL; + s -> aftersize = 0; // read flags while (CURBYTE())
--- a/lwlink/script.c Sat Aug 11 15:18:58 2012 -0600 +++ b/lwlink/script.c Sat Aug 11 23:29:57 2012 -0600 @@ -70,6 +70,8 @@ static char *lwex0_script = "define basesympat s_%s\n" "define lensympat l_%s\n" + "sectopt .ctors padafter 00,00\n" + "sectopt .dtors padafter 00,00\n" "section init load 0100\n" "section .text\n" "section .data\n" @@ -226,7 +228,94 @@ for ( ; *ptr && isspace(*ptr); ptr++) /* do nothing */ ; - if (!strcmp(line, "define")) + if (!strcmp(line, "sectopt")) + { + char *sn; + char *ptr3; + sectopt_t *so; + + for (ptr2 = ptr; *ptr && !isspace(*ptr2); ptr2++) + /* do nothing */ ; + + if (*ptr2) + *ptr2++ = '\0'; + + while (*ptr2 && isspace(*ptr2)) + ptr2++; + + // section name is at ptr + // ptr2 is the option type + sn = ptr; + + // now ptr2 points to the section option name + for (ptr3 = ptr2; *ptr3 && !isspace(*ptr3); ptr3++) + /* do nothing */ ; + + if (*ptr3) + *ptr3++ = 0; + + while (*ptr3 && isspace(*ptr3)) + ptr3++; + + // now ptr3 points to option value + for (so = section_opts; so; so = so -> next) + { + if (!strcmp(so -> name, sn)) + break; + } + + if (!so) + { + so = lw_alloc(sizeof(sectopt_t)); + so -> name = lw_strdup(sn); + so -> aftersize = 0; + so -> afterbytes = NULL; + so -> next = section_opts; + section_opts = so; + } + + if (!strcmp(ptr2, "padafter")) + { + if (so -> afterbytes) + lw_free(so -> afterbytes); + so -> aftersize = 0; + + for (;;) + { + int v; + char *ptr4; + + while (*ptr3 && isspace(*ptr3)) + ptr3++; + + if (!ptr3) + break; + + v = strtoul(ptr3, &ptr4, 16); + if (ptr3 == ptr4) + break; + + + so -> afterbytes = lw_realloc(so -> afterbytes, so -> aftersize + 1); + so -> afterbytes[so -> aftersize] = v; + so -> aftersize++; + ptr3 = ptr4; + while (*ptr3 && isspace(*ptr3)) + ptr3++; + + if (*ptr3 != ',') + break; + + ptr3++; + } + } + else + { + fprintf(stderr, "%s: bad script line: %s %s\n", scriptfile, line, ptr2); + exit(1); + } + } + else if (!strcmp(line, "define")) { // parse out the definition type for (ptr2 = ptr; *ptr2 && !isspace(*ptr2); ptr2++) @@ -253,8 +342,6 @@ } else { - fprintf(stderr, "%s: bad script line: %s\n", scriptfile, line); - exit(1); } } else if (!strcmp(line, "pad"))