From: Nick Clifton Date: Thu, 9 Apr 2009 16:06:48 +0000 (+0000) Subject: PR 9824 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0c71d7594b0e089d3ab0dbb805cfdcf512bb9ad2;p=binutils-gdb.git PR 9824 * ld.texinfo (Output Section Constraint): New node. Documents the ONLY_IF_RO and ONLY_IF_RW constraints. (Symbolic Constants): New node. Documents the CONSTANT operator. --- diff --git a/ld/ChangeLog b/ld/ChangeLog index f8f49407351..d6c0bbd9331 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,10 @@ +2009-04-09 Nick Clifton + + PR 9824 + * ld.texinfo (Output Section Constraint): New node. Documents the + ONLY_IF_RO and ONLY_IF_RW constraints. + (Symbolic Constants): New node. Documents the CONSTANT operator. + 2009-04-09 Thilo Fischer * emultempl/spuelf.em (embedded_spu_file): Use pex_one in place diff --git a/ld/ld.texinfo b/ld/ld.texinfo index ca460b3bdc4..5a8824241fd 100644 --- a/ld/ld.texinfo +++ b/ld/ld.texinfo @@ -3556,7 +3556,10 @@ The full description of an output section looks like this: @smallexample @group @var{section} [@var{address}] [(@var{type})] : - [AT(@var{lma})] [ALIGN(@var{section_align})] [SUBALIGN(@var{subsection_align})] + [AT(@var{lma})] + [ALIGN(@var{section_align})] + [SUBALIGN(@var{subsection_align})] + [@var{constraint}] @{ @var{output-section-command} @var{output-section-command} @@ -4158,10 +4161,14 @@ section named @samp{/DISCARD/} are not included in the output file. @cindex output section attributes We showed above that the full description of an output section looked like this: + @smallexample @group @var{section} [@var{address}] [(@var{type})] : - [AT(@var{lma})] [ALIGN(@var{section_align})] [SUBALIGN(@var{subsection_align})] + [AT(@var{lma})] + [ALIGN(@var{section_align})] + [SUBALIGN(@var{subsection_align})] + [@var{constraint}] @{ @var{output-section-command} @var{output-section-command} @@ -4169,6 +4176,7 @@ like this: @} [>@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 @var{output-section-command}. In this section we will describe the remaining section attributes. @@ -4178,6 +4186,7 @@ remaining section attributes. * Output Section LMA:: Output section LMA * Forced Output Alignment:: Forced Output Alignment * Forced Input Alignment:: Forced Input Alignment +* Output Section Constraint:: Output section constraint * Output Section Region:: Output section region * Output Section Phdr:: Output section phdr * Output Section Fill:: Output section fill @@ -4311,6 +4320,16 @@ You can force input section alignment within an output section by using SUBALIGN. The value specified overrides any alignment given by input sections, whether larger or smaller. +@node Output Section Constraint +@subsubsection Output Section Constraint +@kindex ONLY_IF_RO +@kindex ONLY_IF_RW +@cindex constraints on output sections +You can specify that an output section should only be created if all +of its input sections are read-only or all of its input sections are +read-write by using the keyword @code{ONLY_IF_RO} and +@code{ONLY_IF_RW} respectively. + @node Output Section Region @subsubsection Output Section Region @kindex >@var{region} @@ -4970,6 +4989,7 @@ expressions. @menu * Constants:: Constants +* Symbolic Constants:: Symbolic constants * Symbols:: Symbol Names * Orphan Sections:: Orphan Sections * Location Counter:: The Location Counter @@ -5022,6 +5042,32 @@ _fourk_4 = 10000o; Note - the @code{K} and @code{M} suffixes cannot be used in conjunction with the base suffixes mentioned above. +@node Symbolic Constants +@subsection Symbolic Constants +@cindex symbolic constants +@kindex CONSTANT +It is possible to refer to target specific constants via the use of +the @code{CONSTANT(@var{name})} operator, where @var{name} is one of: + +@table @code +@item MAXPAGESIZE +@kindex MAXPAGESIZE +The target's maximum page size. + +@item COMMONPAGESIZE +@kindex COMMONPAGESIZE +The target's default page size. +@end table + +So for example: + +@smallexample + .text ALIGN (CONSTANT (MAXPAGESIZE)) : @{ *(.text) @} +@end smallexample + +will create a text section aligned to the largest page boundary +supported by the target. + @node Symbols @subsection Symbol Names @cindex symbol names