@ifinfo
This file documents the @sc{gnu} linker LD version @value{VERSION}.
-Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 1999 Free Software Foundation, Inc.
+Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
@samp{--oformat=srec} are equivalent. Unique abbreviations of the names
of multiple-letter options are accepted.
+Note - if the linker is being invoked indirectly, via a compiler driver
+(eg @samp{gcc}) then all the linker command line options should be
+prefixed by @samp{-Wl,} (or whatever is appropriate for the particular
+compiler driver) like this:
+
+@smallexample
+ gcc -Wl,--startgroup foo.o bar.o -Wl,--endgroup
+@end smallexample
+
+This is important, because otherwise the compiler driver program may
+silently drop the linker options, resulting in a bad link.
+
+Here is a table of the generic command line switches accepted by the GNU
+linker:
+
@table @code
@kindex -a@var{keyword}
@item -a@var{keyword}
@kindex --nmagic
@item -n
@itemx --nmagic
-Set the text segment to be read only, and mark the output as
-@code{NMAGIC} if possible.
+Turn off page alignment of sections, and mark the output as
+@code{NMAGIC} if possible.
@kindex -N
@kindex --omagic
exported.
@kindex --exclude-symbols
-@item --exclude-symbols @var{symbol,symbol,...}
+@item --exclude-symbols @var{symbol},@var{symbol},...
Specifies a list of symbols which should not be automatically
exported. The symbol names may be delimited by commas or colons.
followed by a series of symbol assignments and output section
descriptions enclosed in curly braces.
-The first line in the above example sets the special symbol @samp{.},
-which is the location counter. If you do not specify the address of an
-output section in some other way (other ways are described later), the
-address is set from the current value of the location counter. The
-location counter is then incremented by the size of the output section.
-
The first line inside the @samp{SECTIONS} command of the above example
sets the value of the special symbol @samp{.}, which is the location
counter. If you do not specify the address of an output section in some
@var{output-section-command}
@var{output-section-command}
@dots{}
- @} [>@var{region}] [:@var{phdr} :@var{phdr} @dots{}] [=@var{fillexp}]
+ @} [>@var{region}] [AT>@var{lma_region}] [:@var{phdr} :@var{phdr} @dots{}] [=@var{fillexp}]
@end group
@end smallexample
*(.text)
@end smallexample
@noindent
-Here the @samp{*} is a wildcard which matches any file name. To exclude a file
-from matching the file name wildcard, EXCLUDE_FILE may be used to match all files
-except the one specified by EXCLUDE_FILE. For example:
+Here the @samp{*} is a wildcard which matches any file name. To exclude a list
+of files from matching the file name wildcard, EXCLUDE_FILE may be used to
+match all files except the ones specified in the EXCLUDE_FILE list. For
+example:
@smallexample
-(*(EXCLUDE_FILE (*crtend.o) .ctors))
+(*(EXCLUDE_FILE (*crtend.o *otherfile.o) .ctors))
@end smallexample
-will cause all .ctors sections from all files except crtend.o to be included.
+will cause all .ctors sections from all files except @file{crtend.o} and
+@file{otherfile.o} to be included.
There are two ways to include more than one section:
@smallexample
@var{output-section-command}
@var{output-section-command}
@dots{}
- @} [>@var{region}] [:@var{phdr} :@var{phdr} @dots{}] [=@var{fillexp}]
+ @} [>@var{region}] [AT>@var{lma_region}] [:@var{phdr} :@var{phdr} @dots{}] [=@var{fillexp}]
@end group
@end smallexample
We've already described @var{section}, @var{address}, and
@node Output Section LMA
@subsubsection Output section LMA
+@kindex AT>@var{lma_region}
@kindex AT(@var{lma})
@cindex load address
@cindex section load address
The linker will normally set the LMA equal to the VMA. You can change
that by using the @code{AT} keyword. The expression @var{lma} that
-follows the @code{AT} keyword specifies the load address of the section.
+follows the @code{AT} keyword specifies the load address of the
+section. Alternatively, with @samp{AT>@var{lma_region}} expression,
+you may specify a memory region for the section's load address. @xref{MEMORY}.
@cindex ROM initialized data
@cindex initialized data in ROM