@setfilename ld.info
@c $Id$
@syncodeindex ky cp
-@smallbook
+@c @smallbook
@c @cropmarks
@ifinfo
@ifinfo
This file documents the GNU linker GLD.
-Copyright (C) 1991 Free Software Foundation, Inc.
+Copyright (C) 1991, 1992 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
@subtitle The GNU linker
@sp 1
@subtitle Second Edition---@code{gld} version 2.0
-@subtitle April 1991
+@subtitle January 1992
@author Steve Chamberlain and Roland Pesch
@author Cygnus Support
@page
@end tex
@vskip 0pt plus 1filll
-Copyright @copyright{} 1991 Free Software Foundation, Inc.
+Copyright @copyright{} 1991, 1992 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
@end ifinfo
@menu
-* Overview:: Overview
-* Invocation:: Invocation
-* Commands:: Command Language
-* Machine Dependent:: Machine Dependent Features
-* BFD:: BFD
-* Index:: Index
+* Overview:: Overview
+* Invocation:: Invocation
+* Commands:: Command Language
+* Machine Dependent:: Machine Dependent Features
+* BFD:: BFD
+* MRI:: MRI Compatible Script Files
+* Index:: Index
--- The Detailed Node Listing ---
Invocation
-* Options:: Command Line Options
-* Environment:: Environment Variables
+* Options:: Command Line Options
+* Environment:: Environment Variables
Command Language
-* Scripts:: Linker Scripts
-* Expressions:: Expressions
-* MEMORY:: MEMORY Command
-* SECTIONS:: SECTIONS Command
-* Entry Point:: The Entry Point
-* Other Commands:: Other Commands
+* Scripts:: Linker Scripts
+* Expressions:: Expressions
+* MEMORY:: MEMORY Command
+* SECTIONS:: SECTIONS Command
+* Entry Point:: The Entry Point
+* Other Commands:: Other Commands
Expressions
-* Integers:: Integers
-* Symbols:: Symbol Names
-* Location Counter:: The Location Counter
-* Operators:: Operators
-* Evaluation:: Evaluation
-* Assignment:: Assignment: Defining Symbols
-* Built-ins:: Built-In Functions
+* Integers:: Integers
+* Symbols:: Symbol Names
+* Location Counter:: The Location Counter
+* Operators:: Operators
+* Evaluation:: Evaluation
+* Assignment:: Assignment: Defining Symbols
+* Built-ins:: Built-In Functions
SECTIONS Command
-* Section Definition:: Section Definitions
-* Section Contents:: Section Contents
-* Section Options:: Optional Section Attributes
+* Section Definition:: Section Definitions
+* Section Contents:: Section Contents
+* Section Options:: Optional Section Attributes
Machine Dependent Features
-* H8/300:: @code{gld} and the H8/300
-* i960:: @code{gld} and the Intel 960 family
-* m68k:: @code{gld} and the Motorola 68000 family
-* m88k:: @code{gld} and the Motorola 880x0 family
+* H8/300:: @code{gld} and the H8/300
+* i960:: @code{gld} and the Intel 960 family
+* m68k:: @code{gld} and the Motorola 68000 family
+* m88k:: @code{gld} and the Motorola 880x0 family
@code{gld} and the Intel 960 family
-* i960-arch:: Linking for a Specific i960 Architecture
-* i960-emulation:: Emulating Other i960 Linkers
-* i960-commands:: Command Language Extensions for i960
+* i960-arch:: Linking for a Specific i960 Architecture
+* i960-emulation:: Emulating Other i960 Linkers
+* i960-commands:: Command Language Extensions for i960
BFD
-* BFD outline:: How it works: an outline of BFD
-* BFD information loss:: Information Loss
-* Mechanism:: Mechanism
+* BFD outline:: How it works: an outline of BFD
+* BFD information loss:: Information Loss
+* Mechanism:: Mechanism
@end menu
@node Overview, Invocation, Top, Top
and through environment variables.
@menu
-* Options:: Command Line Options
-* Environment:: Environment Variables
+* Options:: Command Line Options
+* Environment:: Environment Variables
@end menu
@node Options, Environment, Invocation, Invocation
@smallexample
gld [-o @var{output} ] @var{objfiles}@dots{}
[ -A@var{architecture} ] [ -b @var{input-format} ] [ -Bstatic ]
- [ -c @var{commandfile} ] [ -d | -dc | -dp ]
+ [ -c @var{MRI-commandfile} ] [ -d | -dc | -dp ]
[ -defsym @var{symbol} = @var{expression} ]
[ -e @var{entry} ] [ -F ] [ -F @var{format} ]
[ -format @var{input-format} ] [ -g ] [ -i ]
This flag is accepted for command-line compatibility with the SunOS linker,
but has no effect on @code{gld}.
-@kindex -c @var{cmdfile}
-@cindex script files
-@item -c @var{commandfile}
-Directs @code{gld} to read link commands from the file
-@var{commandfile}. These commands will completely override @code{gld}'s
-default link format (rather than adding to it); @var{commandfile} must
-specify everything necessary to describe the target format.
-@xref{Commands}.
+@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 such script files
+with the option flag @samp{-c}.
-You may also include a script of link commands directly in the command
-line by bracketing it between @samp{@{} and @samp{@}} characters.
+Use the @samp{-T} option to run linker scripts written in the general-purpose
+@code{ld} scripting language.
@cindex common allocation
@kindex -d
@item -T @var{commandfile}
@itemx -T@var{commandfile}
@kindex -T @var{script}
-Equivalent to @code{-c @var{commandfile}}; supported for compatibility with
-other tools.
+@cindex script files
+Directs @code{gld} to read link commands from the file
+@var{commandfile}. These commands will completely override @code{gld}'s
+default link format (rather than adding to it); @var{commandfile} must
+specify everything necessary to describe the target format.
+@xref{Commands}.
+
+You may also include a script of link commands directly in the command
+line by bracketing it between @samp{@{} and @samp{@}} characters.
@item -t
@kindex -t
@node Environment, , Options, Invocation
@section Environment Variables
-You can condition the behavior of @code{gld} with two environment
+You can change the behavior of @code{gld} with two environment
variables: @code{GNUTARGET} and @code{LDEMULATION}. Depending on the
setting of the latter, other environment variables may be used as well.
@end itemize
You may supply a command file (also known as a link script) to the
-linker either explicitly through the @code{-c} option, or implicitly as
+linker either explicitly through the @code{-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.
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
+* Scripts:: Linker Scripts
+* Expressions:: Expressions
+* MEMORY:: MEMORY Command
+* SECTIONS:: SECTIONS Command
+* Entry Point:: The Entry Point
+* Other Commands:: Other Commands
@end menu
@node Scripts, Expressions, Commands, Commands
@end itemize
@menu
-* Integers:: Integers
-* Symbols:: Symbol Names
-* Location Counter:: The Location Counter
-* Operators:: Operators
-* Evaluation:: Evaluation
-* Assignment:: Assignment: Defining Symbols
-* Built-ins:: Built-In Functions
+* 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, Symbols, Expressions, Expressions
order in the first input file.
@menu
-* Section Definition:: Section Definitions
-* Section Contents:: Section Contents
-* Section Options:: Optional Section Attributes
+* Section Definition:: Section Definitions
+* Section Contents:: Section Contents
+* Section Options:: Optional Section Attributes
@end menu
@node Section Definition, Section Contents, SECTIONS, SECTIONS
functionality are not listed.
@menu
-* H8/300:: @code{gld} and the H8/300
-* i960:: @code{gld} and the Intel 960 family
-* m68k:: @code{gld} and the Motorola 68000 family
-* m88k:: @code{gld} and the Motorola 880x0 family
+* H8/300:: @code{gld} and the H8/300
+* i960:: @code{gld} and the Intel 960 family
+* m68k:: @code{gld} and the Motorola 68000 family
+* m88k:: @code{gld} and the Motorola 880x0 family
@end menu
@node H8/300, i960, Machine Dependent, Machine Dependent
@cindex i960 support
@menu
-* i960-arch:: Linking for a Specific i960 Architecture
-* i960-emulation:: Emulating Other i960 Linkers
-* i960-commands:: Command Language Extensions for i960
+* i960-arch:: Linking for a Specific i960 Architecture
+* i960-emulation:: Emulating Other i960 Linkers
+* i960-commands:: Command Language Extensions for i960
@end menu
@node i960-arch, i960-emulation, i960, i960
For other settings of @code{LDEMULATION}, consult
@ref{Environment,,Environment Variables}.
-@node BFD, Index, Machine Dependent, Top
+@node BFD, MRI, Machine Dependent, Top
@chapter BFD
@cindex back end
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
+* BFD outline:: How it works: an outline of BFD
+* BFD information loss:: Information Loss
+* Mechanism:: Mechanism
@end menu
@node BFD outline, BFD information loss, BFD, BFD
between formats (COFF, IEEE and Oasys).
@end table
-@node Index, , BFD, Top
+@node MRI, Index, BFD, Top
+@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
+{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 whatever; it's only accepted 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{@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 whatsoever 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 whatever
+order they first appear in the input files. In an MRI-compatible
+script, you can override this 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)
+This command supplies a value (@var{expression}) for an 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, , MRI, Top
@unnumbered Index
@printindex cp
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