Extend description of --add-gnu-debuglink option to explain why the file must exist.

[deliverable/binutils-gdb.git] / binutils / doc / binutils.texi

diff --git a/binutils/doc/binutils.texi b/binutils/doc/binutils.texi
index a5bfd4c0b44eb8368852d9ccdae127ec273a04dc..22d54bebfede058bf0021e6df30f9a625d65867e 100644 (file)
--- a/binutils/doc/binutils.texi
+++ b/binutils/doc/binutils.texi
@@ -1091,6 +1091,7 @@ objcopy [@option{-F} @var{bfdname}|@option{--target=}@var{bfdname}]
         [@option{--set-section-flags} @var{sectionpattern}=@var{flags}]
         [@option{--add-section} @var{sectionname}=@var{filename}]
         [@option{--dump-section} @var{sectionname}=@var{filename}]
+        [@option{--update-section} @var{sectionname}=@var{filename}]
         [@option{--rename-section} @var{oldname}=@var{newname}[,@var{flags}]]
         [@option{--long-section-names} @{enable,disable,keep@}]
         [@option{--change-leading-char}] [@option{--remove-leading-char}]
@@ -1489,6 +1490,21 @@ that it does not create a formatted file, it just dumps the contents
 as raw binary data, without applying any relocations.  The option can
 be specified more than once.
 
+@item --update-section @var{sectionname}=@var{filename}
+Replace the existing contents of a section named @var{sectionname}
+with the contents of file @var{filename}.  The size of the section
+will be adjusted to the size of the file.  The section flags for
+@var{sectionname} will be unchanged.  For ELF format files the section
+to segment mapping will also remain unchanged, something which is not
+possible using @option{--remove-section} followed by
+@option{--add-section}.  The option can be specified more than once.
+
+Note - it is possible to use @option{--rename-section} and
+@option{--update-section} to both update and rename a section from one
+command line.  In this case, pass the original section name to
+@option{--update-section}, and the original and new section names to
+@option{--rename-section}.
+
 @item --rename-section @var{oldname}=@var{newname}[,@var{flags}]
 Rename a section from @var{oldname} to @var{newname}, optionally
 changing the section's flags to @var{flags} in the process.  This has
@@ -1668,8 +1684,42 @@ Prefix all the names of all allocated sections in the output file with
 @var{string}.
 
 @item --add-gnu-debuglink=@var{path-to-file}
-Creates a .gnu_debuglink section which contains a reference to @var{path-to-file}
-and adds it to the output file.
+Creates a .gnu_debuglink section which contains a reference to
+@var{path-to-file} and adds it to the output file.  Note: the file at
+@var{path-to-file} must exist.  Part of the process of adding the
+.gnu_debuglink section involves embedding a checksum of the contents
+of the debug info file into the section.
+
+If the debug info file is built in one location but it is going to be
+installed at a later time into a different location then do not use
+the path to the installed location.  The @option{--add-gnu-debuglink}
+option will fail because the installed file does not exist yet.
+Instead put the debug info file in the current directory and use the
+@option{--add-gnu-debuglink} option without any directory components,
+like this:
+
+@smallexample
+ objcopy --add-gnu-debuglink=foo.debug
+@end smallexample
+ 
+At debug time the debugger will attempt to look for the separate debug
+info file in a set of known locations.  The exact set of these
+locations varies depending upon the distribution being used, but it
+typically includes:
+
+@table @code
+
+@item * The same directory as the executable.
+
+@item * A sub-directory of the directory containing the executable
+called .debug
+
+@item * A global debug directory such as /usr/lib/debug.
+@end table
+
+As long as the debug info file has been installed into one of these
+locations before the debugger is run everything should work
+correctly.
 
 @item --keep-file-symbols
 When stripping a file, perhaps with @option{--strip-debug} or