Wed Nov 3 23:31:19 1999 Jeffrey A Law (law@cygnus.com)

[binutils-gdb.git] / ld / ld.texinfo

diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 43e7e82bf1cef0c5302b30264d4ff945af9ecf9b..4494370aa8be2660786ad748638f6accc090f6ff 100644 (file)
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -404,6 +404,14 @@ purpose: the @code{-b}, @code{--format}, @code{--oformat} options, the
 environment variable.  The @sc{gnu} linker will ignore the @code{-F}
 option when not creating an ELF shared object.
 
+@cindex finalization function
+@kindex -fini
+@item -fini @var{name}
+When creating an ELF executable or shared object, call NAME when the
+executable or shared object is unloaded, by setting DT_FINI to the
+address of the function.  By default, the linker uses @code{_fini} as
+the function to call.
+
 @kindex -g
 @item -g
 Ignored.  Provided for compatibility with other tools.
@@ -434,6 +442,14 @@ field rather than the using the file name given to the linker.
 @item -i
 Perform an incremental link (same as option @samp{-r}).
 
+@cindex initialization function
+@kindex -init
+@item -init @var{name}
+When creating an ELF executable or shared object, call NAME when the
+executable or shared object is loaded, by setting DT_INIT to the address
+of the function.  By default, the linker uses @code{_init} as the
+function to call.
+
 @cindex archive files, from cmd line
 @kindex -l@var{archive}
 @kindex --library=@var{archive}
@@ -1366,7 +1382,7 @@ option is given.  Note that the symbols @code{DllMain@@12},
 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.
 
@@ -3410,6 +3426,39 @@ followed by a 1000 byte gap.  Then the @samp{.text} section from
 @samp{.text} section from @file{file3}.  The notation @samp{= 0x1234}
 specifies what data to write in the gaps (@pxref{Output Section Fill}).
 
+@cindex dot inside sections
+Note: @code{.} actually refers to the byte offset from the start of the
+current containing object.  Normally this is the @code{SECTIONS}
+statement, whoes start address is 0, hence @code{.} can be used as an
+absolute address.  If @code{.} is used inside a section description
+however, it refers to the byte offset from the start of that section,
+not an absolute address.  Thus in a script like this:
+
+@smallexample
+SECTIONS
+@{
+    . = 0x100
+    .text: @{
+      *(.text)
+      . = 0x200
+    @}
+    . = 0x500
+    .data: @{
+      *(.data)
+      . += 0x600
+    @}
+@}
+@end smallexample
+
+The @samp{.text} section will be assigned a starting address of 0x100
+and a size of exactly 0x200 bytes, even if there is not enough data in
+the @samp{.text} input sections to fill this area.  (If there is too
+much data, an error will be produced because this would be an attempt to
+move @code{.} backwards).  The @samp{.data} section will start at 0x500
+and it will have an extra 0x600 bytes worth of space after the end of
+the values from the @samp{.data} input sections and before the end of
+the @samp{.data} output section itself.
+
 @need 2000
 @node Operators
 @subsection Operators
@@ -3879,7 +3928,7 @@ not itself call any subroutines).
 @section @code{ld}'s support for interworking between ARM and Thumb code
 
 @cindex ARM interworking support
-@cindex --support-old-code
+@kindex --support-old-code
 For the ARM, @code{ld} will generate code stubs to allow functions calls
 betweem ARM and Thumb code.  These stubs only work with code that has
 been compiled and assembled with the @samp{-mthumb-interwork} command
@@ -3891,6 +3940,15 @@ which will work with non-interworking aware ARM code.  Note, however,
 the linker does not support generating stubs for function calls to
 non-interworking aware Thumb code.
 
+@cindex thumb entry point
+@cindex entry point, thumb
+@kindex --thumb-entry=@var{entry}
+The @samp{--thumb-entry} switch is a duplicate of the generic
+@samp{--entry} switch, in that it sets the program's starting address.  
+But it also sets the bottom bit of the address, so that it can be
+branched to using a BX instruction, and the program will start
+executing in Thumb mode straight away.
+
 @ifclear GENERIC
 @lowersections
 @end ifclear