link editor used by the Link Kit
idld [ options ] filename
idld is used by the Link Kit to relink the UNIX kernel.
The idld command combines several COFF format
object files into one, performs
relocation, resolves external symbols, and supports symbol table information
for symbolic debugging. It creates an executable program by combining one
or more object files and copying the executable result to the file
The filename must name an object or library file.
By convention these names have the ``.o'' (for object)
or ``.a'' (for archive library) extensions.
If more than one name is given, the names must be separated by
one or more spaces. If any input file, filename,
is not an object file, idld assumes it is either an archive library
or a text file containing link editor directives.
By default, the file a.out
is executable if no errors occurred during the load.
If errors occur while linking, idld displays an error message;
the resulting a.out file is unexecutable.
idld concatenates the contents of the given object files
in the order given in the command line. Library files
in the command line are examined only if there are unresolved external
references encountered from previous object files.
The library is searched iteratively to satisfy
as many references as possible and only those routines
that define unresolved external references are concatenated.
The library (archive) symbol table (see
is searched sequentially with as many passes as are necessary to resolve
external references which can be satisfied by library members.
Thus, the ordering of library members is functionally unimportant,
unless multiple library members exist defining the same external symbol.
The library may be either a relocatable archive library
or a shared library.
Object and library files are processed at the point they are encountered
in the argument list, so the order of files in the command line is
important. In general, all object files should be given before
idld sets the entry point of the resulting program to the
beginning of the first routine.
idld recognizes the following options:
Create an absolute file. This is the default if the -r
option is not used. Used with the -r option,
-a allocates memory for common symbols.
Set the default entry point address for the output file to be that of
the symbol epsym.
Set the default fill pattern for ``holes'' within
an output section as well as initialized bss sections.
The argument fill is a two-byte constant.
Search a library libx.a,
where x is up to nine characters.
A library is searched when its name is encountered,
so the placement of a -l is significant.
By default, libraries are located in
LIBDIR or LLIBDIR.
Change the algorithm of searching for libx.a
to look in dir before looking in LIBDIR
and LLIBDIR. This option is effective only if it precedes the
-l option on the command line.
Produce a map or listing of the input/output sections
on the standard output.
Output a message for each multiply-defined external definition.
Put the text section at the beginning of the text segment rather than after
all the header information, and put the data section immediately following
text in the core image.
Set the executable program filename to name instead of
Retain relocation entries in
the output object file. Relocation entries must be saved if the
output file is to become an input file in a subsequent idld
run. The link editor will not complain about unresolved references,
and the output file will not be executable.
Strip line number entries and symbol table information
from the output object file.
Turn off the warning about multiply-defined symbols that are
not the same size.
Designate the specified symbol as undefined.
This is useful for loading entirely from a library, since initially
the symbol table is empty and an unresolved reference is needed to force
the loading of the first routine. The placement of this option on the
idld line is significant;
it must be placed before the library which will define the symbol.
Output a message giving information about the version of
idld being used.
Use num as a decimal version stamp identifying the
a.out file that is produced.
The version stamp is stored in the optional header.
Do not preserve local symbols in the output symbol table;
enter external and static symbols only.
This option saves some space in the output file.
Change the default directory used for finding libraries.
If L is specified, the first default directory which
idld searches, LIBDIR, is replaced by
If U is specified and idld has been built
with a second default directory, LLIBDIR, then that directory
is replaced by dir.
If idld was built with only one default directory and
U is specified, a warning is printed and the option is ignored.
Do not bind anything to address zero.
This option will allow runtime detection of null pointers.
idld returns 0 (zero) if it succeeds in linking an executable
output file; it returns a non-zero value if an error occurs.
If the link editor does not recognize an input file as
an object file or an archive file, it will assume that it contains link
editor directives and will attempt to parse it.
This will occasionally produce an error message complaining about
Invoking idld directly is not recommended since failure to give
command line arguments in the correct order can result in errors.
idld is intended for use by the Link Kit only; it cannot link
XENIX x.out binaries. The link editor ld, however,
is capable of linking x.out binaries. ld
is supplied as part of the SCO OpenServer Development System, which also
includes the startup routines, libraries, and header files necessary
for program development.
The source programs for the input object files should conform to
the following rules:
No variable may be located at virtual address 0 (zero) in the program's
When the link editor
is invoked indirectly by
a startup routine is linked with the user's program.
This routine calls
after execution of the main program. If
ld or idld is called
directly, the user must insure that the program calls
The symbols etext, edata, and end
are reserved for use by the link editor.
A user program must not redefine them.
Arithmetic expressions may only have one forward referenced symbol per
idld executable file
Development System libraries
(LIBDIR is usually defined as /lib)
Development System libraries (LLIBDIR is usually defined as /usr/lib)
default output file if -o option is not given
idld is conformant with
AT&T SVID Issue 2.
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003