\input texinfo
-@setfilename gld.info
-@c $Id$
+@setfilename ld.info
@syncodeindex ky cp
+@c @include configdoc.texi
+
+@c @smallbook
+@c @cropmarks
+
@ifinfo
-This file documents the GNU linker GLD.
+@format
+START-INFO-DIR-ENTRY
+* Ld:: The GNU linker.
+END-INFO-DIR-ENTRY
+@end format
+@end ifinfo
-Copyright (C) 1991 Free Software Foundation, Inc.
+@ifinfo
+This file documents the GNU linker LD.
+
+Copyright (C) 1991, 1992, 1993 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.
+Permission is granted to copy and distribute modified versions of this
+manual under the conditions for verbatim copying, provided also that
+the entire resulting derived work is distributed under the terms of a
+permission notice identical to this one.
+
+Permission is granted to copy and distribute translations of this manual
+into another language, under the above conditions for modified versions.
+
@ignore
Permission is granted to process this file through Tex and print the
results, provided the printed document carries copying permission
(this paragraph not being relevant to the printed manual).
@end ignore
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided also that the
-section entitled ``GNU General Public License'' is included exactly as
-in the original, and provided that the entire resulting derived work is
-distributed under the terms of a permission notice identical to this
-one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that the section entitled ``GNU General Public License'' may be
-included in a translation approved by the author instead of in the
-original English.
@end ifinfo
+@iftex
+@finalout
@setchapternewpage odd
-@settitle GLD, the GNU linker
+@settitle Using LD, the GNU linker
@titlepage
-@title{gld}
-@subtitle{The GNU linker}
+@title Using ld
+@subtitle The GNU linker
@sp 1
-@subtitle Second Edition---@code{gld} version 2.0
-@subtitle April 1991
-@author {Steve Chamberlain, Roland Pesch}
-@author {Cygnus Support}
+@subtitle @code{ld} version 2
+@subtitle March 1993
+@author Steve Chamberlain and Roland Pesch
+@author Cygnus Support
@page
@tex
-\def\$#1${{#1}} % Kluge: collect RCS revision info without $...$
-\xdef\manvers{\$Revision$} % For use in headers, footers too
{\parskip=0pt
\hfill Cygnus Support\par
-\hfill {\it GLD, the GNU linker}, \manvers\par
-\hfill \TeX{}info \texinfoversion\par
\hfill steve\@cygnus.com, pesch\@cygnus.com\par
+\hfill {\it Using LD, the GNU linker}\par
+\hfill Edited by Jeffrey Osier (jeffrey\@cygnus.com), March 1993.\par
}
\global\parindent=0pt % Steve likes it this way.
@end tex
@vskip 0pt plus 1filll
-Copyright @copyright{} 1991 Free Software Foundation, Inc.
+Copyright @copyright{} 1991, 1992, 1993 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions.
@end titlepage
+@end iftex
@c FIXME: Talk about importance of *order* of args, cmds to linker!
-@node Top,,,
@ifinfo
-This file documents the GNU linker gld.
+@node Top
+@top Using ld
+This file documents the GNU linker ld.
+
+@menu
+* Overview:: Overview
+* Invocation:: Invocation
+* Commands:: Command Language
+@ifset GENERIC
+* Machine Dependent:: Machine Dependent Features
+@end ifset
+@ifclear GENERIC
+@ifset H8300
+* H8/300:: ld and the H8/300
+@end ifset
+@ifset I960
+* i960:: ld and the Intel 960 family
+@end ifset
+@end ifclear
+@ifclear SingleFormat
+* BFD:: BFD
+@end ifclear
+@c Following blank line required for remaining bug in makeinfo conds/menus
+
+* MRI:: MRI Compatible Script Files
+* Index:: Index
+@end menu
@end ifinfo
-@node Overview,,,
+@node Overview
@chapter Overview
-@code{gld} combines a number of object and archive files, relocates
-their data and ties up symbol references. Often the last step in
-building a new compiled program to run is a call to @code{gld}.
+@cindex GNU linker
+@cindex what is this?
+@code{ld} combines a number of object and archive files, relocates
+their data and ties up symbol references. Usually the last step in
+compiling a program is to run @code{ld}.
-@code{gld} accepts Linker Command Language files written in
-a superset of AT@&T's Link Editor Command Language syntax,
+@code{ld} accepts Linker Command Language files written in
+a superset of AT&T's Link Editor Command Language syntax,
to provide explicit and total control over the linking process.
-This version of @code{gld} uses the general purpose @code{bfd} libraries
-to operate on object files. This allows @code{gld} to read, combine, and
+@ifclear SingleFormat
+This version of @code{ld} uses the general purpose BFD libraries
+to operate on object files. This allows @code{ld} to read, combine, and
write object files in many different formats---for example, COFF or
@code{a.out}. Different formats may be linked together to produce any
available kind of object file. @xref{BFD} for a list of formats
supported on various architectures.
-
-When linking formats with equivalent representations of debugging
-information (typically variations on one format), @code{gld} maintains
-all debugging information.
-
-@node Invocation,,,
-@chapter Command line options
-
-@c FIXME: -D, -N, -z, -f from older GNU linker, but not currently in new;
-@c FIXME...steve is currently thinking about whether to add them. Maybe
-@c FIXME...remove from document.
-@example
-gld [-o @var{output} ] @var{objfiles}@dots{}
- [ -A@var{architecture} ] [ -b @var{output-format} ] [ -Bstatic ]
- [ -c @var{commandfile} ] [ -D @var{datasize} ]
- [ -d | -dc | -dp ] [ -defsym @var{symbol} = @var{expression} ]
- [ -e @var{entry} ] [ -f @var{fill} ] [ -F ] [ -F @var{format} ]
- [ -format @var{output-format} ] [ -g ] [ -i ]
- [ -l@var{ar} ] [ -L@var{searchdir} ] [ -M | -m ]
- [ -N | -n | -z ] [ -noinhibit-exec ] [ -R @var{filename} ]
- [ -r | -Ur ] [ -S ] [ -s ]
- [ SCRIPT @dots{} ENDSCRIPT ] [ SCRIPT @dots{} @@ ]
- [ -T @var{commandfile} ]
- [ -Ttext @var{textorg} ] [ -Tdata @var{dataorg} ] [ -Tbss @var{bssorg} ]
- [ -t ] [ -u @var{sym}] [-v] [ -X ] [ -x ]
-@end example
+@end ifclear
+
+Aside from its flexibility, the GNU linker is more helpful than other
+linkers in providing diagnostic information. Many linkers abandon
+execution immediately upon encountering an error; whenever possible,
+@code{ld} continues executing, allowing you to identify other errors
+(or, in some cases, to get an output file in spite of the error).
+
+@node Invocation
+@chapter Invocation
+
+The GNU linker @code{ld} is meant to cover a broad range of situations,
+and to be as compatible as possible with other linkers. As a result,
+you have many choices to control its behavior.
+
+@ifset UsesEnvVars
+@menu
+* Options:: Command Line Options
+* Environment:: Environment Variables
+@end menu
+
+@node Options
+@section Command Line Options
+@end ifset
+
+@cindex command line
+@cindex options
+Here is a summary of the options you can use on the @code{ld} command
+line:
+
+@c FIXME! -relax only avail h8/300, i960. Conditionals screwed in examples.
+@smallexample
+ld [-o @var{output} ] @var{objfile}@dots{}
+ [ -A@var{architecture} ] [ -b @var{input-format} ] [ -Bstatic ]
+ [ -c @var{MRI-commandfile} ] [ -d | -dc | -dp ]
+ [ -defsym @var{symbol}=@var{expression} ]
+ [ -e @var{entry} ] [ -F ] [ -F @var{format} ]
+ [ -format @var{input-format} ] [ -g ] [ -G @var{size} ] [ -i ]
+ [ -l@var{ar} ] [ -L@var{searchdir} ] [ -M ] [ -Map @var{mapfile} ]
+ [ -m @var{emulation} ] [ -N | -n ] [ -noinhibit-exec ]
+ [ -oformat @var{output-format} ] [ -R @var{filename} ] [ -relax ]
+ [ -r | -Ur ] [ -S ] [ -s ] [ -T @var{commandfile} ]
+ [ -Ttext @var{textorg} ] [ -Tdata @var{dataorg} ]
+ [ -Tbss @var{bssorg} ] [ -t ] [ -u @var{sym}] [-V] [-v] [ -X ] [-x ]
+ [ -y@var{symbol} ]
+@end smallexample
This plethora of command-line options may seem intimidating, but in
actual practice few of them are used in any particular context.
-For instance, a frequent use of @code{gld} is to link standard Unix
+@cindex standard Unix system
+For instance, a frequent use of @code{ld} is to link standard Unix
object files on a standard, supported Unix system. On such a system, to
link a file @code{hello.o}:
+
@example
-$ gld -o output /lib/crt0.o hello.o -lc
+ld -o @var{output} /lib/crt0.o hello.o -lc
@end example
-This tells @code{gld} to produce a file called @code{output} as the
+
+This tells @code{ld} to produce a file called @var{output} as the
result of linking the file @code{/lib/crt0.o} with @code{hello.o} and
-the library @code{libc.a} which will come from the standard search
-directories.
+the library @code{libc.a}, which will come from the standard search
+directories. (See the discussion of the @samp{-l} option below.)
-The command-line options to @code{gld} may be specified in any order, and
-may be repeated at will. For the most part, repeating an option with a
+The command-line options to @code{ld} may be specified in any order, and
+may be repeated at will. Repeating most options with a
different argument will either have no further effect, or override prior
-occurrences (those further to the left on the command line) of an
+occurrences (those further to the left on the command line) of that
option.
-The exceptions---which may meaningfully be used more than once---
-are @code{-L}, @code{-l}, and @code{-u}.
-@c FIXME: probably some new opts can be repeated meaningfully too.
-
-The list of object files to be linked together, shown as @var{objfiles},
-may follow, precede, or be mixed in with command-line options; save that
-an @var{objfiles} argument may not be placed between an option flag and
+@ifclear SingleFormat
+The exceptions---which may meaningfully be used more than once---are
+@samp{-A}, @samp{-b} (or its synonym @samp{-format}), @samp{-defsym},
+@samp{-L}, @samp{-l}, @samp{-R}, and @samp{-u}.
+@end ifclear
+@ifset SingleFormat
+The exceptions---which may meaningfully be used more than once---are
+@samp{-A}, @samp{-defsym}, @samp{-L}, @samp{-l}, @samp{-R}, and @samp{-u}.
+@end ifset
+
+@cindex object files
+The list of object files to be linked together, shown as @var{objfile}@dots{},
+may follow, precede, or be mixed in with command-line options, except that
+an @var{objfile} argument may not be placed between an option and
its argument.
-Option arguments must follow the option letter without intervening
+Usually the linker is invoked with at least one object file, but other
+forms of binary input files can also be specified with @samp{-l},
+@samp{-R}, and the script command language. If @emph{no} binary input
+files at all are specified, the linker does not produce any output, and
+issues the message @samp{No input files}.
+
+Option arguments must either follow the option letter without intervening
whitespace, or be given as separate arguments immediately following the
option that requires them.
@table @code
-@item @var{objfiles}@dots{}
-The object files @var{objfiles} to be linked; at least one must be specified.
+@item @var{objfile}@dots{}
+The object files to be linked.
+@ifset I960
+@cindex architectures
+@kindex -A@var{arch}
@item -A@var{architecture}
-In the current release of @code{gld}, this option is useful only for the
-Intel 960 family of architectures. In that context, the
-@var{architecture} argument is one of the two-letter names identifying
-members of the 960 family; the option specifies the desired output
-target, and warns of any incompatible instructions in the input files.
-It also selects archive libraries supporting the particular
-architecture; its effect in this regard is similar to that of @code{-l}, save
-that @code{-A}@var{architecture} triggers a two-level search; first for a
-library with exactly the name you specify as @var{architecture}, and if
-that fails, for a library named with the @code{-l} convention---i.e.,
-@samp{lib@var{architecture}.a}.
-
-Future releases of @code{gld} may support similar functionality for
+In the current release of @code{ld}, this option is useful only for the
+Intel 960 family of architectures. In that @code{ld} configuration, the
+@var{architecture} argument identifies the particular architecture in
+the 960 family, enabling some safeguards and modifying the
+archive-library search path. @xref{i960,,@code{ld} and the Intel 960
+family}, for details.
+
+Future releases of @code{ld} may support similar functionality for
other architecture families.
-
-@item -b @var{output-format}
-Specify the desired output-file binary format. You don't usually need
-to specify this. @code{gld} can determine
-the format of @emph{input} files by inspection, and---in the most frequent
-case, when all input files have the same format, @code{gld} selects the
-same format for output files by default.
-
-You can use this option if you need to link a variety of object formats
-together, or if you wish to force a different output format even though
-you have homogeneous input files.
-
-@var{output-format} is a text string, the name of a particular format
-supported by the BFD libraries. @xref{BFD}.
-
-@code{-format @var{output-format}} has the same effect.
-
+@end ifset
+
+@ifclear SingleFormat
+@cindex binary input format
+@kindex -b @var{format}
+@cindex input format
+@item -b @var{input-format}
+@cindex input format
+Specify the binary format for input object files that follow this option
+on the command line. You don't usually need to specify this, as
+@code{ld} is configured to expect as a default input format the most
+usual format on each machine. @var{input-format} is a text string, the
+name of a particular format supported by the BFD libraries.
+(You can list the available binary formats with @samp{objdump -i}.)
+@w{@samp{-format @var{input-format}}} has the same effect, as does the
+script command @code{TARGET}. @xref{BFD}.
+
+You may want to use this option if you are linking files with an unusual
+binary format. You can also use @samp{-b} to switch formats explicitly (when
+linking object files of different formats), by including
+@samp{-b @var{input-format}} before each group of object files in a
+particular format.
+
+The default format is taken from the environment variable
+@code{GNUTARGET}.
+@ifset UsesEnvVars
+@xref{Environment}.
+@end ifset
+You can also define the input
+format from a script, using the command @code{TARGET}; see @ref{Other
+Commands}.
+@end ifclear
+
+@kindex -Bstatic
@item -Bstatic
-This flag is accepted for command-line compatibility with the SunOS linker,
-but has no effect on @code{gld}.
-
-@item -c @var{commandfile}
-Directs @code{gld} to read link commands from the file
-@var{commandfile}. These commands will override @code{gld}'s
-default link format in its entirety; @var{commandfile} must specify
-everything necessary to specify the target format. @xref{Commands}.
-
-You may also include a script of link commands directly in the command
-line by using the @code{SCRIPT} @dots{} @code{ENDSCRIPT} keywords.
-
-@c FIXME: -D in older GNU linker, not necessarily in new
-@item -D @var{datasize}
-Use this option to specify a target size for the @code{data} segment of
-your linked program. The option is only obeyed if @var{datasize} is
-larger than the natural size of the program's @code{data} segment.
-
-@var{datasize} must be an integer specified in hexadecimal.
-
-@code{ld} will simply increase the size of the @code{data} segment,
-padding the created gap with zeros (or a fill pattern specified with
-@samp{-f}, or using the command language), and reduce the size of the
-@code{bss} segment by the same amount.
-@c FIXME: double-check this w/Steve. Open questions: order? Does it
-@c FIXME...matter whether -f before or after -D? What about -c relative
-@c FIXME...position? fill cmd in default script? Apparently
-@c FIXME...can have multiple fill patterns; which used here?
-
-
+Ignored. This option is accepted for command-line compatibility with
+the SunOS linker.
+
+@kindex -c @var{MRI-cmdfile}
+@cindex compatibility, MRI
+@item -c @var{MRI-commandfile}
+For compatibility with linkers produced by MRI, @code{ld} accepts script
+files written in an alternate, restricted command language, described in
+@ref{MRI,,MRI Compatible Script Files}. Introduce MRI script files with
+the option @samp{-c}; use the @samp{-T} option to run linker
+scripts written in the general-purpose @code{ld} scripting language.
+If @var{MRI-cmdfile} does not exist, @code{ld} looks for it in the directories
+specified by any @samp{-L} options.
+
+@cindex common allocation
+@kindex -d
@item -d
+@kindex -dc
@itemx -dc
+@kindex -dp
@itemx -dp
These three options are equivalent; multiple forms are supported for
-compatibility with other linkers. Any of them options will force
-@code{ld} to assign space to common symbols even if a relocatable output
-file is specified (@code{-r}).
-
-@item -defsym @var{symbol} = @var{expression}
-Create a global symbol, in the output file, set to the absolute address
-given by @var{expression}. A limited form of arithmetic is supported
-for the @var{expression} in this context: you may give a hexadecimal
-constant, or use @code{+} and @code{-} to add or subtract hexacedimal
-constants. If you need more elaborate expressions, consider using the
-linker command language from a script.
-
+compatibility with other linkers. They
+assign space to common symbols even if a relocatable output file is
+specified (with @samp{-r}). The script command
+@code{FORCE_COMMON_ALLOCATION} has the same effect. @xref{Other
+Commands}.
+
+@cindex symbols, from command line
+@kindex -defsym @var{symbol}=@var{exp}
+@item -defsym @var{symbol}=@var{expression}
+Create a global symbol in the output file, containing the absolute
+address given by @var{expression}. You may use this option as many
+times as necessary to define multiple symbols in the command line. A
+limited form of arithmetic is supported for the @var{expression} in this
+context: you may give a hexadecimal constant or the name of an existing
+symbol, or use @code{+} and @code{-} to add or subtract hexadecimal
+constants or symbols. If you need more elaborate expressions, consider
+using the linker command language from a script (@pxref{Assignment, ,
+Assignment: Symbol Definitions}). @emph{Note:} there should be no
+white space between @var{symbol}, the equals sign (``@key{=}''), and
+@var{expression}.
+
+@cindex entry point, from command line
+@kindex -e @var{entry}
@item -e @var{entry}
Use @var{entry} as the explicit symbol for beginning execution of your
program, rather than the default entry point. @xref{Entry Point}, for a
discussion of defaults and other ways of specifying the
entry point.
-@c FIXME: -f in older GNU linker, not necessarily in new
-@item -f @var{fill}
-Sets the default fill pattern for ``holes'' in the output file to
-the lowest two bytes of the expression specified.
-
+@ifclear SingleFormat
+@kindex -F
@item -F
-@itemx -F{format}
-Some older linkers required the specification of object-file format,
-even when all input files were homogeneous, and used this option for
-that purpose. @code{gld} doesn't usually require this information---it
-automatically recognizes input-file object format---but it accepts the
-option flag for compatibility with old scripts.
-
-@item -format @var{output-format}
-Synonym for @code{-b} @var{output-format}.
-
+@itemx -F@var{format}
+Ignored. Some older linkers used this option throughout a compilation
+toolchain for specifying object-file format for both input and output
+object files. The mechanisms @code{ld} uses for this purpose (the
+@samp{-b} or @samp{-format} options for input files, the @code{TARGET}
+command in linker scripts for output files, the @code{GNUTARGET}
+environment variable) are more flexible, but @code{ld} accepts the
+@samp{-F} option for compatibility with scripts written to call the old
+linker.
+
+@kindex -format
+@item -format @var{input-format}
+Synonym for @samp{-b @var{input-format}}.
+@end ifclear
+
+@kindex -g
@item -g
-Accepted, but ignored; provided for compatibility with other tools.
+Ignored. Provided for compatibility with other tools.
+@kindex -G
+@cindex object size
+@item -G@var{value}
+@itemx -G @var{value}
+Set the maximum size of objects to be optimized using the GP register to
+@var{size} under MIPS ECOFF. Ignored for other object file formats.
+
+@kindex -i
+@cindex incremental link
@item -i
-Produce an incremental link (same as option @code{-r}).
+Perform an incremental link (same as option @samp{-r}).
+@cindex archive files, from cmd line
+@kindex -l@var{ar}
@item -l@var{ar}
-Add an archive file @var{ar} to the list of files to link. This
+Add archive file @var{ar} to the list of files to link. This
option may be used any number of times. @code{ld} will search its
path-list for occurrences of @code{lib@var{ar}.a} for every @var{ar}
specified.
-@c FIXME: -l also has a side effect of using the "c++ demangler" if we happen
-@c FIXME...to specify -llibg++. Document? pesch@@cygnus.com, 24jan91
-
+@cindex search directory, from cmd line
+@kindex -L@var{dir}
@item -L@var{searchdir}
-This command adds path @var{searchdir} to the list of paths that
-@code{gld} will search for archive libraries. You may use this option
-any number of times.
+Add path @var{searchdir} to the list of paths that @code{ld} will search
+for archive libraries and @code{ld} control scripts. You may use this
+option any number of times.
-@c Should we make any attempt to list the standard paths searched
-@c without listing? When hacking on a new system I often want to know
-@c this, but this may not be the place... it's not constant across
-@c systems, of course, which is what makes it interesting.
-@c pesch@@cygnus.com, 24jan91.
+@ifset UsesEnvVars
+The default set of paths searched (without being specified with
+@samp{-L}) depends on which emulation mode @code{ld} is using, and in
+some cases also on how it was configured. @xref{Environment}.
+@end ifset
+The paths can also be specified in a link script with the
+@code{SEARCH_DIR} command.
+
+@cindex link map
+@kindex -M
@item -M
-@itemx -m
-Print (to the standard output file) a link map---diagnostic information
+Print (to the standard output) a link map---diagnostic information
about where symbols are mapped by @code{ld}, and information on global
common storage allocation.
-@c FIXME: -N in older GNU linker, not necessarily in new
+@cindex link map
+@kindex -Map
+@item -Map @var{mapfile}
+Print to the file @var{mapfile} a link map---diagnostic information
+about where symbols are mapped by @code{ld}, and information on global
+common storage allocation.
+
+@cindex emulation
+@kindex -m @var{emulation}
+@item -m@var{emulation}
+@itemx -m @var{emulation}
+Emulate the @var{emulation} linker. You can list the available
+emulations with the @samp{-V} option. The
+default is the system for which you configured @code{ld}.
+
+@kindex -N
+@cindex read/write from cmd line
+@kindex OMAGIC
@item -N
-specifies readable and writable @code{text} and @code{data} sections. If
-the output format supports Unix style magic numbers, the output is
-marked as @code{OMAGIC}.
+Set the text and data sections to be readable and writable. Also, do
+not page-align the data segment. If the output format supports Unix
+style magic numbers, mark the output as @code{OMAGIC}.
@item -n
-sets the text segment to be read only, and @code{NMAGIC} is written
-if possible.
+@kindex -n
+@cindex read-only text
+@kindex NMAGIC
+Set the text segment to be read only, and mark the output as
+@code{NMAGIC} if possible.
@item -noinhibit-exec
+@cindex output file after errors
+@kindex -noinhibit-exec
+Retain the executable output file whenever it is still usable.
Normally, the linker will not produce an output file if it encounters
-errors during the link process. With this flag, you can specify that
-you wish the output file retained for even after non-fatal errors.
+errors during the link process; it exits without writing an output file
+when it issues any error whatsoever.
@item -o @var{output}
-@var{output} is a name for the program produced by @code{ld}; if this
-option is not specified, the name @samp{a.out} is used by default.
+@kindex -o @var{output}
+@cindex naming the output file
+Use @var{output} as the name for the program produced by @code{ld}; if this
+option is not specified, the name @file{a.out} is used by default. The
+script command @code{OUTPUT} can also specify the output file name.
+
+@kindex -oformat
+@item -oformat @var{output-format}
+Specify the binary format for the output object file. You don't usually
+need to specify this, as @code{ld} is configured to produce as a default
+output format the most usual format on each machine.
+@var{output-format} is a text string, the name of a particular format
+supported by the BFD libraries. (You can list the available binary
+formats with @samp{objdump -i}.) The script command
+@code{OUTPUT_FORMAT} can also specify the output format, but this option
+overrides it. @xref{BFD}.
@item -R @var{filename}
-Read symbol names and their addresses from @var{filename}, but do not
-relocate it or include it in the output. This allows your output file
-to refer symbolically to absolute locations of memory defined in other
-programs.
-@c FIXME: -R accurate? Motivation? Kernel memory, shared mem?
+@kindex -R @var{file}
+@cindex symbol-only input
+On some platforms, this option performs global optimizations
+that become possible when the linker resolves addressing in the
+program, such as relaxing address modes and synthesizing new
+instructions in the output object file.
+
+@item -relax
+@kindex -relax
+@cindex synthesizing linker
+@cindex relaxing addressing modes
+An option with machine dependent effects. Currently this option is only
+supported on the H8/300.
+@ifset H8300
+@xref{H8/300,,@code{ld} and the H8/300}.
+@end ifset
+
+On some platforms, use option performs global optimizations that
+become possible when the linker resolves addressing in the program, such
+as relaxing address modes and synthesizing new instructions in the
+output object file.
+
+On platforms where this is not supported, @samp{-relax} is accepted, but
+ignored.
@item -r
@cindex partial link
-Generates relocatable output---i.e., generate an output file that can in
-turn serve as input to @code{gld}. This is often called @dfn{partial
-linking}. As a side effect, this option also sets the output file's
-magic number to @code{OMAGIC}; see @samp{-N}. If this option is not
-specified, an absolute file is produced. When linking C++ programs,
-this option @emph{will not} resolve references to constructors;
-@samp{-Ur} is an alternative.
+@cindex relocatable output
+@kindex -r
+Generate relocatable output---i.e., generate an output file that can in
+turn serve as input to @code{ld}. This is often called @dfn{partial
+linking}. As a side effect, in environments that support standard Unix
+magic numbers, this option also sets the output file's magic number to
+@code{OMAGIC}.
+@c ; see @code{-N}.
+If this option is not specified, an absolute file is produced. When
+linking C++ programs, this option @emph{will not} resolve references to
+constructors; to do that, use @samp{-Ur}.
+
+This option does the same as @code{-i}.
@item -S
-Omits debugger symbol information (but not all symbols) from the output file.
+@kindex -S
+@cindex strip debugger symbols
+Omit debugger symbol information (but not all symbols) from the output file.
@item -s
-Omits all symbol information from the output file.
-
-@item SCRIPT @dots @@
-@itemx SCRIPT @dots ENDSCRIPT
-You can, if you wish, include a script of linker commands directly in
-the command line instead of referring to it via an input file. When the
-keyword @code{SCRIPT} occurs on the command line, the linker switches to
-interpreting the command language until the end of the list of commands
-is reached---flagged with either an at sign @samp{@@} or with the
-keyword @code{ENDSCRIPT}. Other command-line options will not be
-recognized while parsing the script. @xref{Commands} for a description
-of the command language.
+@kindex -s
+@cindex strip all symbols
+Omit all symbol information from the output file.
@item -Tbss @var{bssorg}
+@kindex -Tbss @var{bssorg}
@itemx -Tdata @var{dataorg}
+@kindex -Tdata @var{dataorg}
@itemx -Ttext @var{textorg}
-Use @var{textorg} as the starting address for---respectively---the
+@kindex -Ttext @var{textorg}
+@cindex segment origins, cmd line
+Use @var{org} as the starting address for---respectively---the
@code{bss}, @code{data}, or the @code{text} segment of the output file.
-@var{textorg} must be a hexadecimal integer.
+@var{org} must be a single hexadecimal integer;
+for compatibility with other linkers, you may omit the leading
+@samp{0x} usually associated with hexadecimal values.
@item -T @var{commandfile}
@itemx -T@var{commandfile}
-Equivalent to @code{-c @var{commandfile}}; supported for compatibility with
-other tools.
+@kindex -T @var{script}
+@cindex script files
+Read link commands from the file
+@var{commandfile}. These commands completely override @code{ld}'s
+default link format (rather than adding to it); @var{commandfile} must
+specify everything necessary to describe the target format.
+@xref{Commands}.
+If @var{commandfile} does not exist, @code{ld} looks for it in the directories
+specified by any @samp{-L} options.
+
+You may also include a script of link commands directly in the command
+line by bracketing it between @samp{@{} and @samp{@}}.
@item -t
-Prints names of input files as @code{ld} processes them.
+@kindex -t
+@cindex verbose
+@cindex input files, displaying
+Print the names of the input files as @code{ld} processes them.
@item -u @var{sym}
-Forces @var{sym} to be entered in the output file as an undefined symbol.
-This may, for example, trigger linking of additional modules from
-standard libraries. @code{-u} may be repeated with different option
-arguments to enter additional undefined symbols. This option is equivalent
-to the @code{EXTERN} linker command.
+@kindex -u @var{sym}
+@cindex undefined symbol
+Force @var{sym} to be entered in the output file as an undefined symbol.
+Doing this may, for example, trigger linking of additional modules from
+standard libraries. @samp{-u} may be repeated with different option
+arguments to enter additional undefined symbols.
+@c Nice idea, but no such command: This option is equivalent
+@c to the @code{EXTERN} linker command.
@item -Ur
+@kindex -Ur
@cindex constructors
For anything other than C++ programs, this option is equivalent to
@samp{-r}: it generates relocatable output---i.e., an output file that can in
-turn serve as input to @code{gld}. When linking C++ programs, @samp{-Ur}
+turn serve as input to @code{ld}. When linking C++ programs, @samp{-Ur}
@emph{will} resolve references to constructors, unlike @samp{-r}.
+@item -V
+@kindex -V
+@cindex version
+Display the version number for @code{ld} and list the supported emulations.
+Print which input files can and can not be opened.
+
@item -v
+@kindex -v
@cindex version
-@cindex verbose
-``Verbose'' switch: display informative messages, including the version
-numbers for @code{gld} and BFD, information on files opened, and BFD
-subroutine calls.
+Display the version number for @code{ld}.
+Print which input files can and can not be opened.
@item -X
-If @code{-s} or @code{-S} is also specified, delete only local symbols
+@kindex -X
+@cindex local symbols, deleting
+@cindex L, deleting symbols beginning
+If @samp{-s} or @samp{-S} is also specified, delete only local symbols
beginning with @samp{L}.
@item -x
-If @code{-s} or @code{-S} is also specified, delete all local symbols,
+@kindex -x
+@cindex deleting local symbols
+If @samp{-s} or @samp{-S} is also specified, delete all local symbols,
not just those beginning with @samp{L}.
-@c FIXME: -z in older GNU linker, not necessarily in new
-@item -z
-Specifies a read-only, demand pageable, and shared @code{text} segment.
-If the output format supports Unix-style magic numbers, @code{-z} also
-marks the output as @code{ZMAGIC}, the default.
-
-@c FIXME: why is following here?. Is it useful to say '-z -r' for
-@c FIXME...instance, or is this just a ref to other ways of setting
-@c FIXME...magic no?
-Specifying a relocatable output file (@code{-r}) will also set the magic
-number to @code{OMAGIC}.
-
-See description of @samp{-N}.
+@item -y@var{symbol}
+@kindex -y@var{symbol}
+@cindex symbol tracing
+Print the name of each linked file in which @var{symbol} appears. This
+option may be given any number of times. On many systems it is necessary
+to prepend an underscore.
+This option is useful when you have an undefined symbol in your link but
+don't know where the reference is coming from.
@end table
-@node Commands,,,
+@ifset UsesEnvVars
+@node Environment
+@section Environment Variables
+
+You can change the behavior of @code{ld} with the environment
+variable @code{GNUTARGET}.
+
+@kindex GNUTARGET
+@cindex default input format
+@code{GNUTARGET} determines the input-file object format if you don't
+use @samp{-b} (or its synonym @samp{-format}). Its value should be one
+of the BFD names for an input format (@pxref{BFD}). If there is no
+@code{GNUTARGET} in the environment, @code{ld} uses the natural format
+of the host. If @code{GNUTARGET} is set to @code{default} then BFD attempts to discover the
+input format by examining binary input files; this method often
+succeeds, but there are potential ambiguities, since there is no method
+of ensuring that the magic number used to specify object-file formats is
+unique. However, the configuration procedure for BFD on each system
+places the conventional format for that system first in the search-list,
+so ambiguities are resolved in favor of convention.
+@end ifset
+
+@node Commands
@chapter Command Language
-@c FIXME: is this a good place to talk about LDEMULATION env var?
-@c FIXME...Apparently some commands "subtly different" depending on
-@c FIXME...whether this set to eg "link960", "gld960", "gld". What is
-@c FIXME...full set of possibilities, what is default? Config-dep?
-
-The command language allows explicit control over the link process,
+@cindex command files
+The command language provides explicit control over the link process,
allowing complete specification of the mapping between the linker's
-input files and its output. This includes:
+input files and its output. It controls:
@itemize @bullet
-@item input files
-@item file formats
-@item output file format
-@item addresses of sections
-@item placement of common blocks
+@item
+input files
+@item
+file formats
+@item
+output file format
+@item
+addresses of sections
+@item
+placement of common blocks
@end itemize
-A command file may be supplied to the linker, either explicitly through
-the @code{-c} option, or implicitly as an ordinary file. If the linker
-opens a file which it cannot recognize as a supported object or archive
-format, it tries to interpret the file as a command file.
-
-@node Scripts,,,
+You may supply a command file (also known as a link script) to the
+linker either explicitly through the @samp{-T} option, or implicitly as
+an ordinary file. If the linker opens a file which it cannot recognize
+as a supported object or archive format, it tries to interpret the file
+as a command file.
+
+You can also include a script directly on the @code{ld} command line,
+delimited by the characters @samp{@{} and @samp{@}}.
+
+@menu
+* Scripts:: Linker Scripts
+* Expressions:: Expressions
+* MEMORY:: MEMORY Command
+* SECTIONS:: SECTIONS Command
+* Entry Point:: The Entry Point
+* Other Commands:: Other Commands
+@end menu
+
+@node Scripts
@section Linker Scripts
-The @code{gld} command language is a collection of statements; some are
-simple keywords setting a particular flag, some are used to select and
-group input files or name output files; and two particular statement
+The @code{ld} command language is a collection of statements; some are
+simple keywords setting a particular option, some are used to select and
+group input files or name output files; and two statement
types have a fundamental and pervasive impact on the linking process.
-The most fundamental command of the @code{gld} command language is the
+@cindex fundamental script commands
+@cindex commands, fundamental
+@cindex output file layout
+@cindex layout of output file
+The most fundamental command of the @code{ld} command language is the
@code{SECTIONS} command (@pxref{SECTIONS}). Every meaningful command
script must have a @code{SECTIONS} command: it specifies a
``picture'' of the output file's layout, in varying degrees of detail.
No other command is required in all cases.
The @code{MEMORY} command complements @code{SECTIONS} by describing the
-available memory in the target architecture; if it is not present,
-sufficient memory is assumed to be available in a contiguous block for
-all output. @xref{MEMORY}.
+available memory in the target architecture. This command is optional;
+if you don't use a @code{MEMORY} command, @code{ld} assumes sufficient
+memory is available in a contiguous block for all output.
+@xref{MEMORY}.
-@node Expressions,,,
+@cindex comments
+You may include comments in linker scripts just as in C: delimited
+by @samp{/*} and @samp{*/}. As in C, comments are syntactically
+equivalent to whitespace.
+
+@node Expressions
@section Expressions
+@cindex expression syntax
+@cindex arithmetic
Many useful commands involve arithmetic expressions. The syntax for
expressions in the command language is identical to that of C
expressions, with the following features:
@itemize @bullet
-@item All expressions evaluated as integers and
+@item
+All expressions evaluated as integers and
are of ``long'' or ``unsigned long'' type.
-@item All constants are integers.
-@item All of the C arithmetic operators are provided.
-@item Global variables may be referenced, defined and created.
-@item Built in functions may be called.
+@item
+All constants are integers.
+@item
+All of the C arithmetic operators are provided.
+@item
+You may reference, define, and create global variables.
+@item
+You may call special purpose built-in functions.
@end itemize
-@node Integers,,,
+@menu
+* Integers:: Integers
+* Symbols:: Symbol Names
+* Location Counter:: The Location Counter
+* Operators:: Operators
+* Evaluation:: Evaluation
+* Assignment:: Assignment: Defining Symbols
+* Built-ins:: Built-In Functions
+@end menu
+
+@node Integers
@subsection Integers
+@cindex integer notation
+@cindex octal integers
An octal integer is @samp{0} followed by zero or more of the octal
digits (@samp{01234567}).
@example
+_as_octal = 0157255;
@end example
+@cindex decimal integers
A decimal integer starts with a non-zero digit followed by zero or
more digits (@samp{0123456789}).
@example
-_as_octal = 0157255;
+_as_decimal = 57005;
@end example
+@cindex hexadecimal integers
+@kindex 0x
A hexadecimal integer is @samp{0x} or @samp{0X} followed by one or
more hexadecimal digits chosen from @samp{0123456789abcdefABCDEF}.
@example
_as_hex = 0xdead;
@end example
-Decimal integers have the usual values. To denote a negative integer, use
+@cindex negative integers
+To write a negative integer, use
the prefix operator @samp{-}; @pxref{Operators}.
@example
-_as_decimal = 57005;
_as_neg = -57005;
@end example
+@cindex scaled integers
+@cindex K and M integer suffixes
+@cindex M and K integer suffixes
+@cindex suffixes for integers
+@cindex integer suffixes
Additionally the suffixes @code{K} and @code{M} may be used to scale a
constant by
+@c TEXI2ROFF-KILL
+@ifinfo
+@c END TEXI2ROFF-KILL
+@code{1024} or @code{1024*1024}
+@c TEXI2ROFF-KILL
+@end ifinfo
@tex
${\rm 1024}$ or ${\rm 1024}^2$
@end tex
-@ifinfo
-1024 or 1024*1024
-@end ifinfo
-respectively. For example, the following all refer to the same quantity:@refill
+@c END TEXI2ROFF-KILL
+respectively. For example, the following all refer to the same quantity:
@example
- _4k_1 = 4K;
- _4k_2 = 4096;
- _4k_3 = 0x1000;
+ _fourk_1 = 4K;
+ _fourk_2 = 4096;
+ _fourk_3 = 0x1000;
@end example
-@node Symbols,,,
+@node Symbols
@subsection Symbol Names
+@cindex symbol names
+@cindex names
+@cindex quoted symbol names
+@kindex "
Unless quoted, symbol names start with a letter, underscore, point or
-minus sign and may include any letters, underscores, digits, points,
+hyphen and may include any letters, underscores, digits, points,
and minus signs. Unquoted symbol names must not conflict with any
keywords. You can specify a symbol which contains odd characters or has
the same name as a keyword, by surrounding the symbol name in double quotes:
"with a space" = "also with a space" + 10;
@end example
+@node Location Counter
@subsection The Location Counter
+@kindex .
+@cindex dot
+@cindex location counter
+@cindex current output location
The special linker variable @dfn{dot} @samp{.} always contains the
current output location counter. Since the @code{.} always refers to
a location in an output section, it must always appear in an
may appear anywhere that an ordinary symbol is allowed in an
expression, but its assignments have a side effect. Assigning a value
to the @code{.} symbol will cause the location counter to be moved.
+@cindex holes
This may be used to create holes in the output section. The location
counter may never be moved backwards.
@example
- SECTIONS
+SECTIONS
+@{
+ output :
@{
- output :
- @{
- file1(.text)
- . = . + 1000;
- file2(.text)
- . += 1000;
- file3(.text)
- . -= 32;
- file4(.text)
- @} = 0x1234;
- @}
+ file1(.text)
+ . = . + 1000;
+ file2(.text)
+ . += 1000;
+ file3(.text)
+ @} = 0x1234;
+@}
@end example
-In the previous example, @code{file1} is located at the beginning of
-the output section, then there is a 1000 byte gap, filled with 0x1234.
-Then @code{file2} appears, also with a 1000 byte gap following before
-@code{file3} is loaded. Then the first 32 bytes of @code{file4} are
-placed over the last 32 bytes of @code{file3}.
+@noindent
+In the previous example, @code{file1} is located at the beginning of the
+output section, then there is a 1000 byte gap. Then @code{file2}
+appears, also with a 1000 byte gap following before @code{file3} is
+loaded. The notation @samp{= 0x1234} specifies what data to write in
+the gaps (@pxref{Section Options}).
-@node Operators,,,
+@node Operators
@subsection Operators
+@cindex Operators for arithmetic
+@cindex arithmetic operators
+@cindex precedence in expressions
The linker recognizes the standard C set of arithmetic operators, with
the standard bindings and precedence levels:
-@c FIXME: distinguish somehow between prefix, infix in operator table!
-@c FIXME: is it fair to include assignments below? Don't they
-@c FIXME...require trailing ; when no other exprs do?
+@c TEXI2ROFF-KILL
@ifinfo
+@c END TEXI2ROFF-KILL
@example
-precedence associativity Operators
+precedence associativity Operators Notes
(highest)
-1 left ! - ~
-2 left * / %
-3 left + -
-4 left >> <<
-5 left == != > < <= >=
-6 left &
-7 left |
-8 left &&
-9 left ||
-10 right ? :
-11 right &= += -= *= /=
+1 left ! - ~ (1)
+2 left * / %
+3 left + -
+4 left >> <<
+5 left == != > < <= >=
+6 left &
+7 left |
+8 left &&
+9 left ||
+10 right ? :
+11 right &= += -= *= /= (2)
(lowest)
@end example
+Notes:
+(1) Prefix operators
+(2) @xref{Assignment}
+@c TEXI2ROFF-KILL
@end ifinfo
-@c FIXME: simplify, debug TeX form of this table!
@tex
-
-\vbox{\offinterlineskip
+\vskip \baselineskip
+%"lispnarrowing" is the extra indent used generally for @example
+\hskip\lispnarrowing\vbox{\offinterlineskip
\hrule
\halign
-{\vrule#&\hfil#\hfil&\vrule#&\hfil#\hfil&\vrule#&\hfil#\hfil&\vrule#\cr
-height2pt&&&&&\cr
-&Level&& associativity &&Operators&\cr
-height2pt&&&&&\cr
+{\vrule#&\strut\hfil\ #\ \hfil&\vrule#&\strut\hfil\ #\ \hfil&\vrule#&\strut\hfil\ {\tt #}\ \hfil&\vrule#\cr
+height2pt&\omit&&\omit&&\omit&\cr
+&Precedence&& Associativity &&{\rm Operators}&\cr
+height2pt&\omit&&\omit&&\omit&\cr
\noalign{\hrule}
-height2pt&&&&&\cr
+height2pt&\omit&&\omit&&\omit&\cr
&highest&&&&&\cr
-&1&&left&&$ ! - ~$&\cr
-height2pt&&&&&\cr
-&2&&left&&* / \%&\cr
-height2pt&&&&&\cr
-&3&&left&&+ -&\cr
-height2pt&&&&&\cr
-&4&&left&&$>> <<$&\cr
-height2pt&&&&&\cr
-&5&&left&&$== != > < <= >=$&\cr
-height2pt&&&&&\cr
+% '176 is tilde, '~' in tt font
+&1&&left&&\qquad- \char'176\ !\qquad\dag&\cr
+&2&&left&&* / \%&\cr
+&3&&left&&+ -&\cr
+&4&&left&&>> <<&\cr
+&5&&left&&== != > < <= >=&\cr
&6&&left&&\&&\cr
-height2pt&&&&&\cr
&7&&left&&|&\cr
-height2pt&&&&&\cr
&8&&left&&{\&\&}&\cr
-height2pt&&&&&\cr
&9&&left&&||&\cr
-height2pt&&&&&\cr
-&10&&right&&? :&\cr
-height2pt&&&&&\cr
-&11&&right&&$${\&= += -= *= /=}&\cr
+&10&&right&&? :&\cr
+&11&&right&&\qquad\&= += -= *= /=\qquad\ddag&\cr
&lowest&&&&&\cr
-height2pt&&&&&\cr}
+height2pt&\omit&&\omit&&\omit&\cr}
\hrule}
@end tex
+@iftex
+{
+@obeylines@parskip=0pt@parindent=0pt
+@dag@quad Prefix operators.
+@ddag@quad @xref{Assignment}.
+}
+@end iftex
+@c END TEXI2ROFF-KILL
-@node Evaluation,,,
+@node Evaluation
@subsection Evaluation
+@cindex lazy evaluation
+@cindex expression evaluation order
The linker uses ``lazy evaluation'' for expressions; it only calculates
an expression when absolutely necessary. The linker needs the value of
the start address, and the lengths of memory regions, in order to do any
output sections) is available for use in the symbol assignment
expression.
-@node Assignment,,,
+@node Assignment
@subsection Assignment: Defining Symbols
-
+@cindex assignment in scripts
+@cindex symbol definition, scripts
+@cindex variables, defining
You may create global symbols, and assign values (addresses) to global
symbols, using any of the C assignment operators:
@table @code
@item @var{symbol} = @var{expression} ;
+@itemx @var{symbol} &= @var{expression} ;
@itemx @var{symbol} += @var{expression} ;
@itemx @var{symbol} -= @var{expression} ;
@itemx @var{symbol} *= @var{expression} ;
@itemx @var{symbol} /= @var{expression} ;
@end table
-Two things distinguish assignment from other operators in @code{gld}
+Two things distinguish assignment from other operators in @code{ld}
expressions.
@itemize @bullet
-@item Assignment may only be used at the root of an expression;
+@item
+Assignment may only be used at the root of an expression;
@samp{a=b+3;} is allowed, but @samp{a+b=3;} is an error.
-@item A trailing semicolon is required at the end of an assignment
-statement.
+
+@kindex ;
+@cindex semicolon
+@item
+You must place a trailing semicolon (``@key{;}'') at the end of an
+assignment statement.
@end itemize
Assignment statements may appear:
@itemize @bullet
-@item as commands in their own right in a @code{gld} script; or
-@item as independent statements within a @code{SECTIONS} command; or
-@item as part of the contents of a section definition in a
+@item
+as commands in their own right in an @code{ld} script; or
+@item
+as independent statements within a @code{SECTIONS} command; or
+@item
+as part of the contents of a section definition in a
@code{SECTIONS} command.
@end itemize
The first two cases are equivalent in effect---both define a symbol with
-an absolute address; the last case defines a symbol whose address is
+an absolute address. The last case defines a symbol whose address is
relative to a particular section (@pxref{SECTIONS}).
-When a linker expression is evaluated and assigned to a variable it is given
-either an absolute or a relocatable type. An absolute expression type
-is one in which the symbol contains the value that it will have in the
-output file, a relocateable expression type is one in which the value
-is expressed as a fixed offset from the base of a section.
+@cindex absolute and relocatable symbols
+@cindex relocatable and absolute symbols
+@cindex symbols, relocatable and absolute
+When a linker expression is evaluated and assigned to a variable, it is
+given either an absolute or a relocatable type. An absolute expression
+type is one in which the symbol contains the value that it will have in
+the output file, a relocatable expression type is one in which the
+value is expressed as a fixed offset from the base of a section.
The type of the expression is controlled by its position in the script
-file. A symbol assigned within a @code{SECTION} specification is
-created relative to the base of the section, a symbol assigned in any
-other place is created as an absolute symbol. Since a symbol created
-within a @code{SECTION} specification is relative to the base of the
-section it will remain relocatable if relocatable output is requested.
-A symbol may be created with an absolute value even when assigned to
-within a @code{SECTION} specification by using the absolute assignment
-function @code{ABSOLUTE} For example, to create an absolute symbol
-whose address is the last byte of the output section @code{.data}:
+file. A symbol assigned within a section definition is created relative
+to the base of the section; a symbol assigned in any other place is
+created as an absolute symbol. Since a symbol created within a
+section definition is relative to the base of the section, it
+will remain relocatable if relocatable output is requested. A symbol
+may be created with an absolute value even when assigned to within a
+section definition by using the absolute assignment function
+@code{ABSOLUTE}. For example, to create an absolute symbol whose address
+is the last byte of an output section named @code{.data}:
@example
+SECTIONS@{ @dots{}
.data :
@{
*(.data)
_edata = ABSOLUTE(.) ;
@}
+@dots{} @}
@end example
-The linker tries to put off the evaluation of an assignment until
-all the terms in the source expression are known (@pxref{Evaluation}).
-For instance the sizes of sections cannot be known until after
-allocation, so assignments dependent upon these are not performed until
-after allocation. Some expressions, such as those depending upon the
-location counter @dfn{dot}, @samp{.} must be evaluated during
-allocation. If the result of an expression is required, but the value is
-not available, then an error results. For example, attempting to use a
-script like the following
+The linker tries to put off the evaluation of an assignment until all
+the terms in the source expression are known (@pxref{Evaluation}). For
+instance, the sizes of sections cannot be known until after allocation,
+so assignments dependent upon these are not performed until after
+allocation. Some expressions, such as those depending upon the location
+counter @dfn{dot}, @samp{.} must be evaluated during allocation. If the
+result of an expression is required, but the value is not available,
+then an error results. For example, a script like the following
@example
-SECTIONS @{
- text 9+this_isnt_constant:
+SECTIONS @{ @dots{}
+ text 9+this_isnt_constant :
@{ @dots{}
@}
- @}
+@dots{} @}
@end example
-will get the error message ``@code{Non constant expression for initial
+@kindex Non constant expression
+@noindent
+will cause the error message ``@code{Non constant expression for initial
address}''.
-@node Builtins,,,
-@subsection Built in Functions
-The command language provides built in functions for use in
-expressions in link scripts.
-@itemize @bullet
-@item @code{ALIGN(@var{exp})}
-returns the result of the current location counter (@code{.}) aligned to
-the next @var{exp} boundary. @var{exp} must be an expression whose
-value is a power of two. This is equivalent to @samp{(. + @var{exp} -1)
-& ~(@var{exp}-1)}. As an example, to align the output @code{.data}
-section to the next 0x2000 byte boundary after the preceding section and
-to set a variable within the section to the next 0x8000 boundary after
-the input sections:
-@example
- .data ALIGN(0x2000) :@{
- *(.data)
- variable = ALIGN(0x8000);
- @}
-@end example
-
-@item @code{ADDR(@var{section name})}
-returns the absolute address of the named section. Your script must
+@node Built-ins
+@subsection Built-In Functions
+@cindex functions in expression language
+The command language includes a number of built-in
+functions for use in link script expressions.
+@table @code
+@item ABSOLUTE(@var{exp})
+@kindex ABSOLUTE(@var{exp})
+@cindex expression, absolute
+Return the absolute (non-relocatable, as opposed to non-negative) value
+of the expression @var{exp}. Primarily useful to assign an absolute
+value to a symbol within a section definition, where symbol values are
+normally section-relative.
+
+@item ADDR(@var{section})
+@kindex ADDR(@var{section})
+@cindex section address
+Return the absolute address of the named @var{section}. Your script must
previously have defined the location of that section. In the following
-example the @code{symbol_1} and @code{symbol_2} are assigned identical
+example, @code{symbol_1} and @code{symbol_2} are assigned identical
values:
@example
- .output1:
+SECTIONS@{ @dots{}
+ .output1 :
@{
- start_of_output_1 $= .;
- ...
+ start_of_output_1 = ABSOLUTE(.);
+ @dots{}
@}
- .output:
+ .output :
@{
symbol_1 = ADDR(.output1);
symbol_2 = start_of_output_1;
@}
+@dots{} @}
@end example
-@item @code{SIZEOF(@var{section name})}
-returns the size in bytes of the named section, if the section has
-been allocated. In the following example the @code{symbol_1} and
+@item ALIGN(@var{exp})
+@kindex ALIGN(@var{exp})
+@cindex rounding up location counter
+Return the result of the current location counter (@code{.}) aligned to
+the next @var{exp} boundary. @var{exp} must be an expression whose
+value is a power of two. This is equivalent to
+@example
+(. + @var{exp} - 1) & ~(@var{exp} - 1)
+@end example
+
+@code{ALIGN} doesn't change the value of the location counter---it just
+does arithmetic on it. As an example, to align the output @code{.data}
+section to the next @code{0x2000} byte boundary after the preceding
+section and to set a variable within the section to the next
+@code{0x8000} boundary after the input sections:
+@example
+SECTIONS@{ @dots{}
+ .data ALIGN(0x2000): @{
+ *(.data)
+ variable = ALIGN(0x8000);
+ @}
+@dots{} @}
+@end example
+@noindent
+The first use of @code{ALIGN} in this example specifies the location of
+a section because it is used as the optional @var{start} attribute of a
+section definition (@pxref{Section Options}). The second use simply
+defines the value of a variable.
+
+The built-in @code{NEXT} is closely related to @code{ALIGN}.
+
+@item DEFINED(@var{symbol})
+@kindex DEFINED(@var{symbol})
+@cindex symbol defaults
+Return 1 if @var{symbol} is in the linker global symbol table and is
+defined, otherwise return 0. You can use this function to provide default
+values for symbols. For example, the following command-file fragment shows how
+to set a global symbol @code{begin} to the first location in the
+@code{.text} section---but if a symbol called @code{begin} already
+existed, its value is preserved:
+@smallexample
+SECTIONS@{ @dots{}
+ .text : @{
+ begin = DEFINED(begin) ? begin : . ;
+ @dots{}
+ @}
+@dots{} @}
+@end smallexample
+
+@item NEXT(@var{exp})
+@kindex NEXT(@var{exp})
+@cindex unallocated address, next
+Return the next unallocated address that is a multiple of @var{exp}.
+This function is closely related to @code{ALIGN(@var{exp})}; unless you
+use the @code{MEMORY} command to define discontinuous memory for the
+output file, the two functions are equivalent.
+
+@item SIZEOF(@var{section})
+@kindex SIZEOF(@var{section})
+@cindex section size
+Return the size in bytes of the named @var{section}, if that section has
+been allocated. In the following example, @code{symbol_1} and
@code{symbol_2} are assigned identical values:
+@c What does it return if the section hasn't been allocated? 0?
@example
+SECTIONS@{ @dots{}
.output @{
.start = . ;
- ...
- .end = .;
+ @dots{}
+ .end = . ;
@}
- symbol_1 = .end - .start;
+ symbol_1 = .end - .start ;
symbol_2 = SIZEOF(.output);
-@end example
+@dots{} @}
-@item @code{DEFINED(@var{symbol name})}
-Returns 1 if the symbol is in the linker global symbol table and is
-defined, otherwise it returns 0. For example, this command-file fragment
-shows how to set a global symbol @code{begin} to the first location in
-the @code{.text} section---but only if no symbol called @code{begin}
-existed:
-@example
- .text: @{
- begin = DEFINED(begin) ? begin : . ;
- ...
- @}
@end example
-@end itemize
-@node MEMORY,,,
+@item SIZEOF_HEADERS
+@kindex SIZEOF_HEADERS
+@cindex header size
+@itemx sizeof_headers
+@kindex sizeof_headers
+Return the size in bytes of the output file's headers. You can use this number
+as the start address of the first section, if you choose, to facilitate
+paging.
+
+@end table
+
+@node MEMORY
@section MEMORY Command
-The linker's default configuration permits allocation of all memory.
-You can override this by using the @code{MEMORY} command. The
+@kindex MEMORY
+@cindex regions of memory
+@cindex discontinuous memory
+@cindex allocating memory
+The linker's default configuration permits allocation of all available memory.
+You can override this configuration by using the @code{MEMORY} command. The
@code{MEMORY} command describes the location and size of blocks of
memory in the target. By using it carefully, you can describe which
memory regions may be used by the linker, and which memory regions it
available regions, but does move the requested sections into the correct
regions and issue errors when the regions become too full.
-Command files may contain at most one use of the @code{MEMORY}
+The command files may contain at most one use of the @code{MEMORY}
command; however, you can define as many blocks of memory within it as
you wish. The syntax is:
-
+
@example
MEMORY
@{
- @var{name} (@var{attr}): ORIGIN = @var{origin}, LENGTH = @var{len}
- .
- .
- .
+ @var{name} (@var{attr}) : ORIGIN = @var{origin}, LENGTH = @var{len}
+ @dots{}
@}
@end example
@table @code
@item @var{name}
+@cindex naming memory regions
is a name used internally by the linker to refer to the region. Any
symbol name may be used. The region names are stored in a separate
-name space, and will not conflict with symbols, filenames or section
+name space, and will not conflict with symbols, file names or section
names. Use distinct names to specify multiple regions.
@item (@var{attr})
-is an optional list of attributes, parsed for compatibility with the
-AT@&T linker but ignored by the both the AT@&T and the GNU linker.
-Valid attribute lists must be made up of the characters ``@code{RWXL}''.
-If you omit the attribute list, you may omit the parentheses around it
-as well.
+@cindex memory region attributes
+is an optional list of attributes, permitted for compatibility with the
+AT&T linker but not used by @code{ld} beyond checking that the
+attribute list is valid. Valid attribute lists must be made up of the
+characters ``@code{LIRWX}''. If you omit the attribute list, you may
+omit the parentheses around it as well.
@item @var{origin}
-is the start address of the region in physical memory. It is expressed as
-an expression, which must evaluate to a constant before
+@kindex ORIGIN =
+@kindex o =
+@kindex org =
+is the start address of the region in physical memory. It is
+an expression that must evaluate to a constant before
memory allocation is performed. The keyword @code{ORIGIN} may be
abbreviated to @code{org} or @code{o}.
@item @var{len}
+@kindex LENGTH =
+@kindex len =
+@kindex l =
is the size in bytes of the region (an expression).
-The keyword @code{LENGTH} may be abbreviated to @code{len} or @code{l}
+The keyword @code{LENGTH} may be abbreviated to @code{len} or @code{l}.
@end table
For example, to specify that memory has two regions available for
-allocation; one starting at 0 for 256k, and the other starting at
-0x40000000 for four megabytes:
+allocation---one starting at 0 for 256 kilobytes, and the other
+starting at @code{0x40000000} for four megabytes:
@example
MEMORY
@{
- rom : ORIGIN= 0, LENGTH = 256K
- ram : org= 0x40000000, l = 4M
+ rom : ORIGIN = 0, LENGTH = 256K
+ ram : org = 0x40000000, l = 4M
@}
@end example
Once you have defined a region of memory named @var{mem}, you can direct
-specific output sections there by using a command ending in @samp{>@var{mem}}
-within the @code{SECTIONS} command. If the combined output
-sections directed to a region are too big for the region, the linker will
-issue an error message.
+specific output sections there by using a command ending in
+@samp{>@var{mem}} within the @code{SECTIONS} command (@pxref{Section
+Options}). If the combined output sections directed to a region are too
+big for the region, the linker will issue an error message.
-@node SECTIONS,,,
+@node SECTIONS
@section SECTIONS Command
+@kindex SECTIONS
The @code{SECTIONS} command controls exactly where input sections are
placed into output sections, their order and to which output sections
they are allocated.
@end itemize
The first two possibilities---defining the entry point, and defining
-symbols---can also be done outside the @samp{SECTIONS} command:
+symbols---can also be done outside the @code{SECTIONS} command:
@pxref{Entry Point}, @pxref{Assignment}. They are permitted here as
well for your convenience in reading the script, so that symbols or the
entry point can be defined at meaningful points in your output-file
for example, the order of sections in the output file will match the
order in the first input file.
-@node Section Definition,,,
+@menu
+* Section Definition:: Section Definitions
+* Section Contents:: Section Contents
+* Section Options:: Optional Section Attributes
+@end menu
+
+@node Section Definition
@subsection Section Definitions
+@cindex section definition
The most frequently used statement in the @code{SECTIONS} command is
the @dfn{section definition}, which you can use to specify the
properties of an output section: its location, alignment, contents,
-fill pattern, and target memory region can all be specified. Most of
+fill pattern, and target memory region. Most of
these specifications are optional; the simplest form of a section
definition is
@example
-SECTIONS
-@{
-.
-.
-.
+SECTIONS @{ @dots{}
@var{secname} : @{
@var{contents}
@}
-.
-.
-.
-@}
+@dots{} @}
@end example
+@cindex naming output sections
@noindent
@var{secname} is the name of the output section, and @var{contents} a
-specification of what goes there---for example a list of input files or
+specification of what goes there---for example, a list of input files or
sections of input files. As you might assume, the whitespace shown is
-optional; you do need the colon @samp{:} and the braces @samp{@{@}},
+optional. You do need the colon @samp{:} and the braces @samp{@{@}},
however.
@var{secname} must meet the constraints of your output format. In
formats which only support a limited number of sections, such as
@code{a.out}, the name must be one of the names supported by the format
-(in the case of @code{a.out}, @code{.text}, @code{.data} or @code{.bss}). If
-the output format supports any number of sections, but with numbers and
-not names (in the case of IEEE), the name should be supplied as a quoted
-numeric string. A section name may consist of any sequence characters,
-but any name which does not conform to the standard @code{gld} symbol
-name syntax must be quoted.
-
-@node Section Contents,,,
+(@code{a.out}, for example, allows only @code{.text}, @code{.data} or
+@code{.bss}). If the output format supports any number of sections, but
+with numbers and not names (as is the case for Oasys), the name should be
+supplied as a quoted numeric string. A section name may consist of any
+sequence characters, but any name which does not conform to the standard
+@code{ld} symbol name syntax must be quoted.
+@xref{Symbols, , Symbol Names}.
+
+@node Section Contents
@subsection Section Contents
+@cindex contents of a section
In a section definition, you can specify the contents of an output section by
-listing particular object files; by listing particular input-file
-sections; or a combination of the two. You can also place arbitrary
+listing particular object files, by listing particular input-file
+sections, or by a combination of the two. You can also place arbitrary
data in the section, and define symbols relative to the beginning of the
section.
whitespace.
@table @code
-@item @var{filename}( @var{section} )
-@itemx @var{filename}( @var{section}, @var{section}, @dots{} )
-@itemx @var{filename}( @var{section} @var{section} @dots{} )
-You can name one or more sections from your input files, for
-insertion in the current output section. If you wish to specify a list
-of input-file sections inside the parentheses, you may separate the
-section names by either commas or whitespace.
-
@item @var{filename}
+@kindex @var{filename}
+@cindex input files, section defn
+@cindex files, including in output sections
You may simply name a particular input file to be placed in the current
-output section; @emph{all} sections from that file are placed in
-the current section definition. Since multiple statements may be
-present in the contents of a section definition, you can specify a list
-of particular files by name:
+output section; @emph{all} sections from that file are placed in the
+current section definition. To specify a list of particular files by
+name:
@example
-.data: @{ afile.o bfile.o cfile.o @}
+.data : @{ afile.o bfile.o cfile.o @}
@end example
+@noindent
+The example also illustrates that multiple statements can be included in
+the contents of a section definition, since each file name is a separate
+statement.
If the file name has already been mentioned in another section
definition, with an explicit section name list, then only those sections
which have not yet been allocated are used.
+@item @var{filename}( @var{section} )
+@itemx @var{filename}( @var{section}, @var{section}, @dots{} )
+@itemx @var{filename}( @var{section} @var{section} @dots{} )
+@kindex @var{filename}(@var{section})
+@cindex files and sections, section defn
+You can name one or more sections from your input files, for
+insertion in the current output section. If you wish to specify a list
+of input-file sections inside the parentheses, you may separate the
+section names by either commas or whitespace.
+
@item * (@var{section})
@itemx * (@var{section}, @var{section}, @dots{})
-@itemx * (@var{section} @var{section} @dots{})
+@itemx * (@var{section} @var{section} @dots{}
+@cindex input sections to output section
+@kindex *(@var{section})
Instead of explicitly naming particular input files in a link control
-script, you can refer to @emph{all} files from the @code{gld} command
-line: use @samp{*} instead of a particular filename before the
+script, you can refer to @emph{all} files from the @code{ld} command
+line: use @samp{*} instead of a particular file name before the
parenthesized input-file section list.
-For example, to copy sections @code{1} through @code{4} from a Oasys file
+For example, to copy sections @code{1} through @code{4} from an Oasys file
into the @code{.text} section of an @code{a.out} file, and sections @code{13}
and @code{14} into the @code{.data} section:
@example
-SECTION @{
+SECTIONS @{
.text :@{
*("1" "2" "3" "4")
@}
@item [ @var{section} ]
@itemx [ @var{section}, @var{section}, @dots{} ]
@itemx [ @var{section} @var{section} @dots{} ]
+@kindex [ @var{sections} ]
This is an alternate notation to specify named sections from all
unallocated input files; its effect is exactly the same as that of
@samp{* (@var{section}@dots{})}
@item @var{filename}@code{( COMMON )}
-@itemx [ COMMON ]
+@itemx ( COMMON )
+@kindex ( COMMON )
+@cindex uninitialized data
+@cindex commons in output
Specify where in your output file to place uninitialized data
-with this notation. @code{[COMMON]} by itself refers to all
+with this notation. @code{*(COMMON)} by itself refers to all
uninitialized data from all input files (so far as it is not yet
allocated); @var{filename}@code{(COMMON)} refers to uninitialized data
from a particular file. Both are special cases of the general
mechanisms for specifying where to place input-file sections:
-@code{gld} permits you to refer to uninitialized data as if it
+@code{ld} permits you to refer to uninitialized data as if it
were in an input-file section named @code{COMMON}, regardless of the
input file's format.
@end table
-For example, the following command script arranges its output file into
+For example, the following command script arranges the output file into
three consecutive sections, named @code{.text}, @code{.data}, and
@code{.bss}, taking the input for each from the correspondingly named
sections of all the input files:
@example
-SECTIONS
-{
- .text: { *(.text) }
- .data: { *(.data) }
- .bss: { *(.bss) [COMMON] }
-}
+SECTIONS @{
+ .text : @{ *(.text) @}
+ .data : @{ *(.data) @}
+ .bss : @{ *(.bss) *(COMMON) @}
+@}
@end example
The following example reads all of the sections from file @code{all.o}
files are written to output section @code{outputc}.
@example
-SECTIONS
- @{
+SECTIONS @{
outputa 0x10000 :
@{
all.o
*(.input1)
*(.input2)
@}
- @}
+@}
@end example
There are still more kinds of statements permitted in the contents of
-output section definitions! The foregoing statements permitted you to
+output section definitions. The foregoing statements permitted you to
arrange, in your output file, data originating from your input files.
You can also place data directly in an output section from the link
command script. Most of these additional statements involve
@table @code
@item CREATE_OBJECT_SYMBOLS
-instructs the linker to create a symbol for each input file and place it
-into the current section, set with the address of the first byte of
+@kindex CREATE_OBJECT_SYMBOLS
+@cindex input filename symbols
+@cindex filename symbols
+Create a symbol for each input file
+in the current section, set to the address of the first byte of
data written from the input file. For instance, with @code{a.out}
files it is conventional to have a symbol for each input file. You can
accomplish this by defining the output @code{.text} section as follows:
*(.text)
_etext = ALIGN(0x2000);
@}
- .
- .
- .
- @}
+ @dots{}
+@}
@end example
If @code{objsym} is a file containing this script, and @code{a.o},
@example
/* a.c */
-afunction() { }
+afunction() @{ @}
int adata=1;
int abss;
@end example
@noindent
-@samp{gld -M sample a.o b.o c.o d.o} would create a map like this,
+@samp{ld -M sample a.o b.o c.o d.o} would create a map like this,
containing symbols matching the object file names:
@example
00000000 A __DYNAMIC
00002068 t d.o
@end example
-@item FORCE_COMMON_ALLOCATION
-@c FIXME! I don't know what this does.
-
@item @var{symbol} = @var{expression} ;
+@kindex @var{symbol} = @var{expression} ;
@itemx @var{symbol} @var{f}= @var{expression} ;
-@var{symbol} is any symbol name (@pxref{Symbols}). When you assign a
-value to a symbol within a particular section definition, the value is
-relative to the beginning of the section (@pxref{Assignment}). If you write
+@kindex @var{symbol} @var{f}= @var{expression} ;
+@var{symbol} is any symbol name (@pxref{Symbols}). ``@var{f}=''
+refers to any of the operators @code{&= += -= *= /=} which combine
+arithmetic and assignment.
+
+@cindex assignment, in section defn
+When you assign a value to a symbol within a particular section
+definition, the value is relative to the beginning of the section
+(@pxref{Assignment}). If you write
@example
-SECTIONS
-{
+SECTIONS @{
abs = 14 ;
-.
-.
-.
- .data: { @dots{} rel = 14 ; @dots{} }
+ @dots{}
+ .data : @{ @dots{} rel = 14 ; @dots{} @}
abs2 = 14 + ADDR(.data);
-.
-.
-.
-}
+ @dots{}
+@}
@end example
-@c FIXME! Try above example!
+@c FIXME: Try above example!
@noindent
-@code{abs} and @var{rel} do not have the same value; @code{rel} has the
+@code{abs} and @code{rel} do not have the same value; @code{rel} has the
same value as @code{abs2}.
-``@var{f}='' here refers to any of the operators @code{&= += -= *=
-/=} which combine arithmetic and assignment.
-
@item BYTE(@var{expression})
+@kindex BYTE(@var{expression})
@itemx SHORT(@var{expression})
+@kindex SHORT(@var{expression})
@itemx LONG(@var{expression})
+@kindex LONG(@var{expression})
+@cindex direct output
By including one of these three statements in a section definition, you
can explicitly place one, two, or four bytes (respectively) at the
-current address of that section. Multiple-byte quantities are
-represented in whatever byte order is appropriate for the output file
-format (@pxref{BFD}).
+current address of that section.
+
+@ifclear SingleFormat
+Multiple-byte quantities are represented in whatever byte order is
+appropriate for the output file format (@pxref{BFD}).
+@end ifclear
@item FILL(@var{expression})
+@kindex FILL(@var{expression})
+@cindex holes, filling
+@cindex unspecified memory
Specifies the ``fill pattern'' for the current section. Any otherwise
unspecified regions of memory within the section (for example, regions
you skip over by assigning a new value to the location counter @samp{.})
fill patterns in different parts of an output section.
@end table
-@node Section Options,,,
+@node Section Options
@subsection Optional Section Attributes
+@cindex section defn, full syntax
Here is the full syntax of a section definition, including all the
optional portions:
-@example
-SECTIONS
-@{
-.
-.
-.
-@var{secname} @var{start} BLOCK(@var{align}) : @var{contents} =@var{fill} >@var{region}
-.
-.
-.
+@smallexample
+SECTIONS @{
+@dots{}
+@var{secname} @var{start} BLOCK(@var{align}) (NOLOAD) : @{ @var{contents} @} =@var{fill} >@var{region}
+@dots{}
@}
-@end example
+@end smallexample
@var{secname} and @var{contents} are required. @xref{Section
-Definition}, and @pxref{Section Contents} for the details of
-@var{contents}. @var{start}, @code{BLOCK(@var{align)}},
-@code{=@var{fill}}, and @code{>@var{region}} are all optional.
+Definition}, and @pxref{Section Contents} for details on @var{contents}.
+The remaining elements---@var{start}, @code{BLOCK(@var{align)}},
+@code{(NOLOAD)} @code{=@var{fill}}, and @code{>@var{region}}---are all
+optional.
@table @code
@item @var{start}
+@cindex start address, section
+@cindex section start
+@cindex section address
You can force the output section to be loaded at a specified address by
specifying @var{start} immediately following the section name.
@var{start} can be represented as any expression. The following
@code{0x40000000}:
@example
SECTIONS @{
- .
- .
- .
+ @dots{}
output 0x40000000: @{
@dots{}
@}
- .
- .
- .
+ @dots{}
@}
@end example
@item BLOCK(@var{align})
-@c FIXME! Fill in BLOCK(align) description
+@kindex BLOCK(@var{align})
+@cindex section alignment
+@cindex aligning sections
+You can include @code{BLOCK()} specification to advance
+the location counter @code{.} prior to the beginning of the section, so
+that the section will begin at the specified alignment. @var{align} is
+an expression.
+
+@item (NOLOAD)
+@kindex NOLOAD
+@cindex prevent unnecessary loading
+Use @samp{(NOLOAD)} to prevent a section from being loaded into memory
+each time it is accessed. For example, in the script sample below, the
+@code{ROM} segment is addressed at memory location @samp{0} and does not
+need to be loaded into each object file:
+@example
+SECTIONS @{
+ ROM 0 (NOLOAD) : @{ @dots{} @}
+ @dots{}
+@}
+@end example
@item =@var{fill}
-You may use any expression to specify @var{fill}. Including
+@kindex =@var{fill}
+@cindex section fill pattern
+@cindex fill pattern, entire section
+Including
@code{=@var{fill}} in a section definition specifies the initial fill
-value for that section. Any unallocated holes in the current output
+value for that section.
+You may use any expression to specify @var{fill}.
+Any unallocated holes in the current output
section when written to the output file will be filled with the two
least significant bytes of the value, repeated as necessary. You can
also change the fill value with a @code{FILL} statement in the
@var{contents} of a section definition.
@item >@var{region}
-@c FIXME! Fill in >region description
+@kindex >@var{region}
+@cindex section, assigning to memory region
+@cindex memory regions and sections
+Assign this section to a previously defined region of memory.
+@xref{MEMORY}.
@end table
-@node Entry Point,,,
+@node Entry Point
@section The Entry Point
+@kindex ENTRY(@var{symbol})
+@cindex start of execution
+@cindex first instruction
The linker command language includes a command specifically for
defining the first executable instruction in an output file (its
@dfn{entry point}). Its argument is a symbol name:
definitions within the @code{SECTIONS} command---whatever makes the most
sense for your layout.
+@cindex entry point, defaults
@code{ENTRY} is only one of several ways of choosing the entry point.
You may indicate it in any of the following ways (shown in descending
order of priority: methods higher in the list override methods lower down).
@itemize @bullet
@item
-the @code{-e} @var{entry} command-line option;
+the @samp{-e} @var{entry} command-line option;
@item
-the @code{ENTRY} @var{symbol} command in a linker control script;
+the @code{ENTRY(@var{symbol}} command in a linker control script;
@item
the value of the symbol @code{start}, if present;
@item
The address @code{0}.
@end itemize
-For example, you can also generate an entry point with an assignment statement:
-if no symbol @code{start} is defined within your input files, you can
-simply assign it an appropriate value---
+For example, you can use these rules to generate an entry point with an
+assignment statement: if no symbol @code{start} is defined within your
+input files, you can simply define it, assigning it an appropriate
+value---
@example
start = 0x2020;
@end example
convention for the entry point, you can just assign the value of
whatever symbol contains the start address to @code{start}:
@example
-start = other_symbol;
+start = other_symbol ;
@end example
-@node Other Commands,,,
+@node Other Commands
@section Other Commands
The command language includes a number of other commands that you can
use for specialized purposes. They are similar in purpose to
@table @code
@item FLOAT
+@kindex FLOAT
@itemx NOFLOAT
-Declare to the linker whether or not floating point support is
-available. The default assumption is @code{NOFLOAT}.
-@c FIXME: So what? What does it do once it knows FLOAT or NOFLOAT?
+@kindex NOFLOAT
+These keywords were used in some older linkers to request a particular
+math subroutine library. @code{ld} doesn't use the keywords, assuming
+instead that any necessary subroutines are in libraries specified using
+the general mechanisms for linking to archives; but to permit the use of
+scripts that were written for the older linkers, the keywords
+@code{FLOAT} and @code{NOFLOAT} are accepted and ignored.
-@item HLL ( @var{file}, @var{file}, @dots{} )
-@itemx HLL ( @var{file} @var{file} @dots{} )
+@item FORCE_COMMON_ALLOCATION
+@kindex FORCE_COMMON_ALLOCATION
+@cindex common allocation
+This command has the same effect as the @samp{-d} command-line option:
+to make @code{ld} assign space to common symbols even if a relocatable
+output file is specified (@samp{-r}).
@item INPUT ( @var{file}, @var{file}, @dots{} )
+@kindex INPUT ( @var{files} )
@itemx INPUT ( @var{file} @var{file} @dots{} )
+@cindex binary input files
+Use this command to include binary input files in the link, without
+including them in a particular section definition. Files specified this
+way are treated identically to object files listed on the command line.
+@ignore
@item MAP ( @var{name} )
+@kindex MAP ( @var{name} )
+@c MAP(...) appears to look for an F in the arg, ignoring all other
+@c chars; if it finds one, it sets "map_option_f" to true. But nothing
+@c checks map_option_f. Apparently a stub for the future...
+@end ignore
@item OUTPUT ( @var{filename} )
-
-@item SEARCH_DIR ( @var{pathname} )
-
-@item STARTUP ( @var{name} )
-
-@item SYSLIB ( @var{file}, @var{file}, @dots{} )
-@itemx SYSLIB ( @var{file} @var{file} @dots{} )
-
+@kindex OUTPUT ( @var{filename} )
+@cindex naming the output file
+Use this command to name the link output file @var{filename}. The
+effect of @code{OUTPUT(@var{filename})} is identical to the effect of
+@w{@samp{-o @var{filename}}}, and whichever is encountered last will
+control the name actually used to name the output file. In particular,
+you can use this command to supply a default output-file name other than
+@code{a.out}.
+
+@ifclear SingleFormat
+@item OUTPUT_ARCH ( @var{bfdname} )
+@kindex OUTPUT_ARCH ( @var{bfdname} )
+@cindex machine architecture, output
+Specify a particular output machine architecture, with one of the names
+used by the BFD back-end routines (@pxref{BFD}). This command is often
+unnecessary; the architecture is most often set implicitly by either the
+system BFD configuration or as a side effect of the @code{OUTPUT_FORMAT}
+command.
+
+@item OUTPUT_FORMAT ( @var{bfdname} )
+@kindex OUTPUT_FORMAT ( @var{bfdname} )
+@cindex format, output file
+Specify a particular output format, with one of the names used by the
+BFD back-end routines (@pxref{BFD}). This selection will only affect
+the output file; the related command @code{TARGET} affects primarily
+input files.
+@end ifclear
+
+@item SEARCH_DIR ( @var{path} )
+@kindex SEARCH_DIR ( @var{path} )
+@cindex path for libraries
+@cindex search path, libraries
+Add @var{path} to the list of paths where @code{ld} looks for
+archive libraries. @code{SEARCH_DIR(@var{path})} has the same
+effect as @samp{-L@var{path}} on the command line.
+
+@item STARTUP ( @var{filename} )
+@kindex STARTUP ( @var{filename} )
+@cindex first input file
+Ensure that @var{filename} is the first input file used in the link
+process.
+
+@ifclear SingleFormat
@item TARGET ( @var{format} )
-
+@cindex input file format
+@kindex TARGET ( @var{format} )
+Change the input-file object code format (like the command-line option
+@samp{-b} or its synonym @samp{-format}). The argument @var{format} is
+one of the strings used by BFD to name binary formats. In the current
+@code{ld} implementation, if @code{TARGET} is specified but
+@code{OUTPUT_FORMAT} is not, the last @code{TARGET} argument is also
+used as the default format for the @code{ld} output file.
+@xref{BFD}.
+
+@kindex GNUTARGET
+If you don't use the @code{TARGET} command, @code{ld} uses the value of
+the environment variable @code{GNUTARGET}, if available, to select the
+output file format. If that variable is also absent, @code{ld} uses
+the default format configured for your machine in the BFD libraries.
+@end ifclear
@end table
-@node BFD,,,
-@chapter BFD
+@ifset GENERIC
+@node Machine Dependent
+@chapter Machine Dependent Features
+
+@cindex machine dependencies
+@code{ld} has additional features on some platforms; the following
+sections describe them. Machines where @code{ld} has no additional
+functionality are not listed.
+
+@menu
+* H8/300:: @code{ld} and the H8/300
+* i960:: @code{ld} and the Intel 960 family
+@end menu
+@end ifset
+
+@c FIXME! This could use @up/@down, but there seems to be a conflict
+@c between those and node-defaulting.
+@ifset H8300
+@ifclear GENERIC
+@up
+@end ifclear
+@node H8/300
+@section @code{ld} and the H8/300
+
+@cindex H8/300 support
+For the H8/300, @code{ld} can perform these global optimizations when
+you specify the @samp{-relax} command-line option.
-The linker accesses object and archive files using the @code{bfd}
-libraries. These libraries allow the linker to use the same routines
-to operate on object files whatever the object file format.
+@table @emph
+@item relaxing address modes
+@cindex relaxing on H8/300
+@code{ld} finds all @code{jsr} and @code{jmp} instructions whose
+targets are within eight bits, and turns them into eight-bit
+program-counter relative @code{bsr} and @code{bra} instructions,
+respectively.
+
+@item synthesizing instructions
+@cindex synthesizing on H8/300
+@c FIXME: specifically mov.b, or any mov instructions really?
+@code{ld} finds all @code{mov.b} instructions which use the
+sixteen-bit absolute address form, but refer to the top
+page of memory, and changes them to use the eight-bit address form.
+(That is: the linker turns @samp{mov.b @code{@@}@var{aa}:16} into
+@samp{mov.b @code{@@}@var{aa}:8} whenever the address @var{aa} is in the
+top page of memory).
+@end table
+@ifclear GENERIC
+@down
+@end ifclear
+@end ifset
+
+@ifset I960
+@ifclear GENERIC
+@up
+@end ifclear
+@node i960
+@section @code{ld} and the Intel 960 family
+
+@cindex i960 support
+
+You can use the @samp{-A@var{architecture}} command line option to
+specify one of the two-letter names identifying members of the 960
+family; the option specifies the desired output target, and warns of any
+incompatible instructions in the input files. It also modifies the
+linker's search strategy for archive libraries, to support the use of
+libraries specific to each particular architecture, by including in the
+search loop names suffixed with the string identifying the architecture.
+
+For example, if your @code{ld} command line included @w{@samp{-ACA}} as
+well as @w{@samp{-ltry}}, the linker would look (in its built-in search
+paths, and in any paths you specify with @samp{-L}) for a library with
+the names
-A different object file format can be supported simply by creating a
-new @code{bfd} back end and adding it to the library.
+@example
+try
+libtry.a
+tryca
+libtryca.a
+@end example
-Formats currently supported:
-@itemize @bullet
-@item
-Sun3 68k @code{a.out}
-@item
-IEEE-695 68k Object Module Format
-@item
-Oasys 68k Binary Relocatable Object File Format
-@item
-Sun4 sparc @code{a.out}
-@item
-88k bcs coff
-@item
-i960 coff little endian
-@item
-i960 coff big endian
-@item
-i960 @code{b.out} little endian
-@item
-i960 @code{b.out} big endian
-@end itemize
+@noindent
+The first two possibilities would be considered in any event; the last
+two are due to the use of @w{@samp{-ACA}}.
+
+You can meaningfully use @samp{-A} more than once on a command line, since
+the 960 architecture family allows combination of target architectures; each
+use will add another pair of name variants to search for when @w{@samp{-l}}
+specifies a library.
+@ifclear GENERIC
+@down
+@end ifclear
+@end ifset
+
+@ifclear SingleFormat
+@node BFD
+@chapter BFD
+
+@cindex back end
+@cindex object file management
+The linker accesses object and archive files using the BFD libraries.
+These libraries allow the linker to use the same routines to operate on
+object files whatever the object file format. A different object file
+format can be supported simply by creating a new BFD back end and adding
+it to the library. You can use @code{objdump -i}
+(@pxref{objdump,,objdump,binutils.info,The GNU Binary Utilities}) to
+list all the formats available for each architecture under BFD. This
+was the list of formats, and of architectures supported for each format,
+as of the time this manual was prepared:
+@cindex formats available
+@cindex architectures available
+@example
+BFD header file version 0.18
+a.out-i386
+ (header big endian, data big endian)
+ m68k:68020
+ a29k
+ sparc
+ i386
+a.out-sunos-big
+ (header big endian, data big endian)
+ m68k:68020
+ a29k
+ sparc
+ i386
+b.out.big
+ (header big endian, data little endian)
+ i960:core
+b.out.little
+ (header little endian, data little endian)
+ i960:core
+coff-a29k-big
+ (header big endian, data big endian)
+ a29k
+coff-h8300
+ (header big endian, data big endian)
+ H8/300
+coff-i386
+ (header little endian, data little endian)
+ i386
+coff-Intel-big
+ (header big endian, data little endian)
+ i960:core
+coff-Intel-little
+ (header little endian, data little endian)
+ i960:core
+coff-m68k
+ (header big endian, data big endian)
+ m68k:68020
+coff-m88kbcs
+ (header big endian, data big endian)
+ m88k:88100
+ecoff-bigmips
+ (header big endian, data big endian)
+ mips
+ecoff-littlemips
+ (header little endian, data little endian)
+ mips
+elf-big
+ (header big endian, data big endian)
+ m68k:68020
+ vax
+ i960:core
+ a29k
+ sparc
+ mips
+ i386
+ m88k:88100
+ H8/300
+ rs6000:6000
+elf-little
+ (header little endian, data little endian)
+ m68k:68020
+ vax
+ i960:core
+ a29k
+ sparc
+ mips
+ i386
+ m88k:88100
+ H8/300
+ rs6000:6000
+ieee
+ (header big endian, data big endian)
+ m68k:68020
+ vax
+ i960:core
+ a29k
+ sparc
+ mips
+ i386
+ m88k:88100
+ H8/300
+ rs6000:6000
+srec
+ (header big endian, data big endian)
+ m68k:68020
+ vax
+ i960:core
+ a29k
+ sparc
+ mips
+ i386
+ m88k:88100
+ H8/300
+ rs6000:6000
+@end example
-As with most implementations, @code{bfd} is a compromise between
+@cindex BFD requirements
+@cindex requirements for BFD
+As with most implementations, BFD is a compromise between
several conflicting requirements. The major factor influencing
-@code{bfd} design was efficiency, any time used converting between
-formats is time which would not have been spent had @code{bfd} not
+BFD design was efficiency: any time used converting between
+formats is time which would not have been spent had BFD not
been involved. This is partly offset by abstraction payback; since
-@code{bfd} simplifies applications and back ends, more time and care
+BFD simplifies applications and back ends, more time and care
may be spent optimizing algorithms for a greater speed.
-One minor artifact of the @code{bfd} solution which the
-user should be aware of is the potential for information loss.
-There are two places where useful information can be lost using the
-@code{bfd} mechanism; during conversion and during output. @xref{BFD
-information loss}.
+One minor artifact of the BFD solution which you should bear in
+mind is the potential for information loss. There are two places where
+useful information can be lost using the BFD mechanism: during
+conversion and during output. @xref{BFD information loss}.
+
+@menu
+* BFD outline:: How it works: an outline of BFD
+* BFD information loss:: Information Loss
+* Mechanism:: Mechanism
+@end menu
-@node BFD outline,,,
+@node BFD outline
@section How it works: an outline of BFD
-When an object file is opened, @code{bfd} subroutines automatically
+@cindex opening object files
+When an object file is opened, BFD subroutines automatically
determine the format of the input object file, and build a descriptor in
memory with pointers to routines that will be used to access elements of
the object file's data structures.
-As different information from the the object files is required
-@code{bfd} reads from different sections of the file and processes them.
-For example a very common operation for the linker is processing symbol
-tables. Each @code{bfd} back end provides a routine for converting
+As different information from the the object files is required,
+BFD reads from different sections of the file and processes them.
+For example, a very common operation for the linker is processing symbol
+tables. Each BFD back end provides a routine for converting
between the object file's representation of symbols and an internal
canonical format. When the linker asks for the symbol table of an object
-file, it calls through the memory pointer to the relevant @code{bfd}
+file, it calls through the memory pointer to the BFD
back end routine which reads and converts the table into a canonical
form. The linker then operates upon the common form. When the link is
finished and the linker writes the symbol table of the output file,
-another @code{bfd} back end routine is called which takes the newly
+another BFD back end routine is called which takes the newly
created symbol table and converts it into the chosen output format.
-@node BFD information loss,,,
+@node BFD information loss
@section Information Loss
@emph{Information can be lost during output.} The output formats
-supported by @code{bfd} do not provide identical facilities, and
+supported by BFD do not provide identical facilities, and
information which may be described in one form has nowhere to go in
another format. One example of this is alignment information in
@code{b.out}. There is nowhere in an @code{a.out} format file to store
Another example is COFF section names. COFF files may contain an
unlimited number of sections, each one with a textual section name. If
-the target of the link is a format which does not have many sections (eg
-@code{a.out}) or has sections without names (eg the Oasys format) the
+the target of the link is a format which does not have many sections (e.g.,
+@code{a.out}) or has sections without names (e.g., the Oasys format) the
link cannot be done simply. You can circumvent this problem by
describing the desired input-to-output section mapping with the command
language.
-@emph{Information lost during canonicalization.} The @code{bfd} internal
-canonical form of the external formats is not exhaustive; there are
-structures in input formats for which there is no direct representation
-internally. This means that the @code{bfd} back ends cannot maintain
-all possible data richness through the transformation between external to
-internal and back to external formats.
+@emph{Information can be lost during canonicalization.} The BFD
+internal canonical form of the external formats is not exhaustive; there
+are structures in input formats for which there is no direct
+representation internally. This means that the BFD back ends
+cannot maintain all possible data richness through the transformation
+between external to internal and back to external formats.
This limitation is only a problem when using the linker to read one
-format and write another. Each @code{bfd} back end is responsible for
-maintaining as much data as possible, and the internal @code{bfd}
-canonical form has structures which are opaque to the @code{bfd} core,
+format and write another. Each BFD back end is responsible for
+maintaining as much data as possible, and the internal BFD
+canonical form has structures which are opaque to the BFD core,
and exported only to the back ends. When a file is read in one format,
-the canonical form is generated for @code{bfd} and the linker. At the
-same time, the back end saves away any information which may otherwise
-be lost. If the data is then written back to the same back end, the back
+the canonical form is generated for BFD and the linker. At the
+same time, the back end saves away any information which would otherwise
+be lost. If the data is then written back in the same format, the back
end routine will be able to use the canonical form provided by the
-@code{bfd} core as well as the information it prepared earlier. Since
-there is a great deal of commonality between back ends, this mechanism
-is very useful. There is no information lost for this reason when
+BFD core as well as the information it prepared earlier. Since
+there is a great deal of commonality between back ends,
+there is no information lost when
linking big endian COFF to little endian COFF, or from @code{a.out} to
@code{b.out}. When a mixture of formats is linked, the information is
only lost from the files whose format differs from the destination.
-@node Mechanism,,,
+@node Mechanism
@section Mechanism
-The greatest potential for loss of information is when there is least
+The greatest potential for loss of information occurs when there is the least
overlap between the information provided by the source format, that
-stored by the canonical format and the information needed by the
+stored by the canonical format, and that needed by the
destination format. A brief description of the canonical form may help
-you appreciate what kinds of data you can count on preserving across
+you understand which kinds of data you can count on preserving across
conversions.
+@cindex BFD canonical format
+@cindex internal object-file format
@table @emph
@item files
-Information on target machine architecture, particular implementation
+Information on target machine architecture, particular implementation,
and format type are stored on a per-file basis. Other information
-includes a demand pageable bit and a write protected bit. Note that
-information like Unix magic numbers is not stored here---only the magic
-numbers' meaning, so a @code{ZMAGIC} file would have both the demand pageable
+includes a demand pagable bit and a write protected bit.
+Information like Unix magic numbers is not stored here---only the magic
+numbers' meaning, so a @code{ZMAGIC} file would have both the demand pagable
bit and the write protected text bit set.
-The byte order of the target is stored on a per-file basis, so that
-both big- and little-endian object files may be linked with one another.
+The byte order of the target is stored on a per-file basis, so that big-
+and little-endian object files may be linked with one another.
@item sections
Each section in the input file contains the name of the section, the
-original address in the object file, various flags, size and alignment
-information and pointers into other @code{bfd} data structures.
+original address in the object file, various options, size and alignment
+information and pointers into other BFD data structures.
@item symbols
Each symbol contains a pointer to the object file which originally
-defined it, its name, value and various flag bits. When a symbol table
-is read in, all symbols are relocated to make them relative to the base
-of the section where they were defined, so that each symbol points to
-its containing section. Each symbol also has a varying amount of hidden
-data to contain private data for the BFD back end. Since the symbol
-points to the original file, the private data format for that symbol is
-accessible. @code{gld} can operate on a collection of symbols of wildly
-different formats without problems.
+defined it, its name, its value, and various option bits. When a
+BFD back end reads in a symbol table, the back end relocates all
+symbols to make them relative to the base of the section where they were
+defined. Doing this ensures that each symbol points to its containing
+section. Each symbol also has a varying amount of hidden
+private data for the BFD back end. Since the symbol points to the
+original file, the private data format for that symbol is accessible.
+@code{ld} can operate on a collection of symbols of wildly different
+formats without problems.
Normal global and simple local symbols are maintained on output, so an
output file (no matter its format) will retain symbols pointing to
functions and to global, static, and common variables. Some symbol
-information is not worth retaining; in @code{a.out} type information is
+information is not worth retaining; in @code{a.out}, type information is
stored in the symbol table as long symbol names. This information would
be useless to most COFF debuggers and may be thrown away with
appropriate command line switches. (The GNU debugger @code{gdb} does
support @code{a.out} style debugging information in COFF).
There is one word of type information within the symbol, so if the
-format supports symbol type information within symbols - (eg COFF,
+format supports symbol type information within symbols (for example, COFF,
IEEE, Oasys) and the type is simple enough to fit within one word
-(nearly everything but aggregates) the information will be preserved.
+(nearly everything but aggregates), the information will be preserved.
@item relocation level
-@c FIXME: I don't understand "relocation record" from this so I can't
-@c FIXME...improve the explanation to make it clear...
-Each canonical relocation record contains a pointer to the symbol to
+Each canonical BFD relocation record contains a pointer to the symbol to
relocate to, the offset of the data to relocate, the section the data
-is in and a pointer to a relocation type descriptor. Relocation is
-performed effectively by message passing through the relocation type
-descriptor and symbol pointer. It allows relocations to be performed
-on output data using a relocation method only available in one of the
+is in, and a pointer to a relocation type descriptor. Relocation is
+performed by passing messages through the relocation type
+descriptor and the symbol pointer. Therefore, relocations can be performed
+on output data using a relocation method that is only available in one of the
input formats. For instance, Oasys provides a byte relocation format.
A relocation record requesting this relocation type would point
indirectly to a routine to perform this, so the relocation may be
performed on a byte being written to a COFF file, even though 68k COFF
has no such relocation type.
+@c FIXME why specific reference to 68K above?
@item line numbers
-Line numbers have to be relocated along with the symbol information.
+Object formats can contain, for debugging purposes, some form of mapping
+between symbols, source line numbers, and addresses in the output file.
+These addresses have to be relocated along with the symbol information.
Each symbol with an associated list of line number records points to the
first record of the list. The head of a line number list consists of a
-pointer to the symbol, which allows divination of the address of the
+pointer to the symbol, which allows finding out the address of the
function whose line number is being described. The rest of the list is
made up of pairs: offsets into the section and line numbers. Any format
which can simply derive this information can pass it successfully
between formats (COFF, IEEE and Oasys).
@end table
+@end ifclear
+
+@node MRI
+@appendix MRI Compatible Script Files
+@cindex MRI compatibility
+To aid users making the transition to @sc{gnu} @code{ld} from the MRI
+linker, @code{ld} can use MRI compatible linker scripts as an
+alternative to the more general-purpose linker scripting language
+described in @ref{Commands,,Command Language}. MRI compatible linker
+scripts have a much simpler command set than the scripting language
+otherwise used with @code{ld}. @sc{gnu} @code{ld} supports the most
+commonly used MRI linker commands; these commands are described here.
+
+You can specify a file containing an MRI-compatible script using the
+@samp{-c} command-line option.
+
+Each command in an MRI-compatible script occupies its own line; each
+command line starts with the keyword that identifies the command (though
+blank lines are also allowed for punctuation). If a line of an
+MRI-compatible script begins with an unrecognized keyword, @code{ld}
+issues a warning message, but continues processing the script.
+
+Lines beginning with @samp{*} are comments.
+
+You can write these commands using all upper-case letters, or all
+lower case; for example, @samp{chip} is the same as @samp{CHIP}.
+The following list shows only the upper-case form of each command.
+
+@table @code
+@item ABSOLUTE @var{secname}
+@item ABSOLUTE @var{secname}, @var{secname}, @dots{} @var{secname}
+@cindex @code{ABSOLUTE} (MRI)
+Normally, @code{ld} includes in the output file all sections from all
+the input files. However, in an MRI-compatible script, you can use the
+@code{ABSOLUTE} command to restrict the sections that will be present in
+your output program. If the @code{ABSOLUTE} command is used at all in a
+script, then only the sections named explicitly in @code{ABSOLUTE}
+commands will appear in the linker output. You can still use other
+input sections (whatever you select on the command line, or using
+@code{LOAD}) to resolve addresses in the output file.
+
+@item ALIAS @var{out-secname}, @var{in-secname}
+@cindex @code{ALIAS} (MRI)
+Use this command to place the data from input section @var{in-secname}
+in a section called @var{out-secname} in the linker output file.
+
+@var{in-secname} may be an integer.
+
+@item BASE @var{expression}
+@cindex @code{BASE} (MRI)
+Use the value of @var{expression} as the lowest address (other than
+absolute addresses) in the output file.
+
+@item CHIP @var{expression}
+@itemx CHIP @var{expression}, @var{expression}
+@cindex @code{CHIP} (MRI)
+This command does nothing; it is accepted only for compatibility.
+
+@item END
+@cindex @code{END} (MRI)
+This command does nothing whatever; it's only accepted for compatibility.
+
+@item FORMAT @var{output-format}
+@cindex @code{FORMAT} (MRI)
+Similar to the @code{OUTPUT_FORMAT} command in the more general linker
+language, but restricted to one of these output formats:
+@enumerate
+@item
+S-records, if @var{output-format} is @samp{S}
+
+@item
+IEEE, if @var{output-format} is @samp{IEEE}
+
+@item
+COFF (the @samp{coff-m68k} variant in BFD), if @var{output-format} is
+@samp{COFF}
+@end enumerate
+
+@item LIST @var{anything}@dots{}
+@cindex @code{LIST} (MRI)
+Print (to the standard output file) a link map, as produced by the
+@code{ld} command-line option @samp{-M}.
+
+The keyword @code{LIST} may be followed by anything on the
+same line, with no change in its effect.
+
+@item LOAD @var{filename}
+@item LOAD @var{filename}, @var{filename}, @dots{} @var{filename}
+@cindex @code{LOAD} (MRI)
+Include one or more object file @var{filename} in the link; this has the
+same effect as specifying @var{filename} directly on the @code{ld}
+command line.
+
+@item NAME @var{output-name}
+@cindex @code{NAME} (MRI)
+@var{output-name} is the name for the program produced by @code{ld}; the
+MRI-compatible command @code{NAME} is equivalent to the command-line
+option @samp{-o} or the general script language command @code{OUTPUT}.
+
+@item ORDER @var{secname}, @var{secname}, @dots{} @var{secname}
+@itemx ORDER @var{secname} @var{secname} @var{secname}
+@cindex @code{ORDER} (MRI)
+Normally, @code{ld} orders the sections in its output file in the
+order in which they first appear in the input files. In an MRI-compatible
+script, you can override this ordering with the @code{ORDER} command. The
+sections you list with @code{ORDER} will appear first in your output
+file, in the order specified.
+
+@item PUBLIC @var{name}=@var{expression}
+@itemx PUBLIC @var{name},@var{expression}
+@itemx PUBLIC @var{name} @var{expression}
+@cindex @code{PUBLIC} (MRI)
+Supply a value (@var{expression}) for external symbol
+@var{name} used in the linker input files.
+
+@item SECT @var{secname}, @var{expression}
+@itemx SECT @var{secname}=@var{expression}
+@itemx SECT @var{secname} @var{expression}
+@cindex @code{SECT} (MRI)
+You can use any of these three forms of the @code{SECT} command to
+specify the start address (@var{expression}) for section @var{secname}.
+If you have more than one @code{SECT} statement for the same
+@var{secname}, only the @emph{first} sets the start address.
+@end table
+
+
+@node Index
+@unnumbered Index
+
+@printindex cp
+
+@tex
+% I think something like @colophon should be in texinfo. In the
+% meantime:
+\long\def\colophon{\hbox to0pt{}\vfill
+\centerline{The body of this manual is set in}
+\centerline{\fontname\tenrm,}
+\centerline{with headings in {\bf\fontname\tenbf}}
+\centerline{and examples in {\tt\fontname\tentt}.}
+\centerline{{\it\fontname\tenit\/} and}
+\centerline{{\sl\fontname\tensl\/}}
+\centerline{are used for emphasis.}\vfill}
+\page\colophon
+% Blame: pesch@cygnus.com, 28mar91.
+@end tex
+
@contents
@bye
projects / deliverable / binutils-gdb.git / blobdiff