[PATCH v3] aarch64: Emit jump slot for conditional branch to undefined symbols

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

diff --git a/ld/ld.texi b/ld/ld.texi
index 9f562935bed06d67708e2cd72d276de5ec694f71..4dc78e65fa251aa5487e3811fff97214b63136c4 100644 (file)
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -31,6 +31,7 @@
 @set MSP430
 @set NDS32
 @set NIOSII
+@set PDP11
 @set POWERPC
 @set POWERPC64
 @set Renesas
@@ -3260,7 +3261,7 @@ an error.
 @kindex --compact-branches
 @item --compact-branches
 @kindex --no-compact-branches
-@item --compact-branches
+@itemx --no-compact-branches
 These options control the generation of compact instructions by the linker
 in the PLT entries for MIPS R6.
 
@@ -3269,6 +3270,73 @@ in the PLT entries for MIPS R6.
 @c man end
 @end ifset
 
+
+@ifset PDP11
+@subsection Options specific to PDP11 targets
+
+@c man begin OPTIONS
+
+For the pdp11-aout target, three variants of the output format can be
+produced as selected by the following options.  The default variant
+for pdp11-aout is the @samp{--omagic} option, whereas for other
+targets @samp{--nmagic} is the default.  The @samp{--imagic} option is
+defined only for the pdp11-aout target, while the others are described
+here as they apply to the pdp11-aout target.
+
+@table @gcctabopt
+
+@kindex -N
+@item -N
+@kindex --omagic
+@itemx --omagic
+
+Mark the output as @code{OMAGIC} (0407) in the @file{a.out} header to
+indicate that the text segment is not to be write-protected and
+shared.  Since the text and data sections are both readable and
+writable, the data section is allocated immediately contiguous after
+the text segment.  This is the oldest format for PDP11 executable
+programs and is the default for @command{ld} on PDP11 Unix systems
+from the beginning through 2.11BSD.
+
+@kindex -n
+@item -n
+@kindex --nmagic
+@itemx --nmagic
+
+Mark the output as @code{NMAGIC} (0410) in the @file{a.out} header to
+indicate that when the output file is executed, the text portion will
+be read-only and shareable among all processes executing the same
+file.  This involves moving the data areas up to the first possible 8K
+byte page boundary following the end of the text.  This option creates
+a @emph{pure executable} format.
+
+@kindex -z
+@item -z
+@kindex --imagic
+@itemx --imagic
+
+Mark the output as @code{IMAGIC} (0411) in the @file{a.out} header to
+indicate that when the output file is executed, the program text and
+data areas will be loaded into separate address spaces using the split
+instruction and data space feature of the memory management unit in
+larger models of the PDP11.  This doubles the address space available
+to the program.  The text segment is again pure, write-protected, and
+shareable.  The only difference in the output format between this
+option and the others, besides the magic number, is that both the text
+and data sections start at location 0.  The @samp{-z} option selected
+this format in 2.11BSD.  This option creates a @emph{separate
+executable} format.
+
+@kindex --no-omagic
+@item --no-omagic
+
+Equivalent to @samp{--nmagic} for pdp11-aout.
+
+@end table
+
+@c man end
+@end ifset
+
 @ifset UsesEnvVars
 @node Environment
 @section Environment Variables
@@ -3589,13 +3657,16 @@ script, and then invoke the linker with nothing but a @samp{-T} option.
 In case a @dfn{sysroot prefix} is configured, and the filename starts
 with the @samp{/} character, and the script being processed was
 located inside the @dfn{sysroot prefix}, the filename will be looked
-for in the @dfn{sysroot prefix}.  Otherwise, the linker will try to
-open the file in the current directory.  If it is not found, the
-linker will search through the archive library search path.
-The @dfn{sysroot prefix} can also be forced by specifying @code{=}
-as the first character in the filename path, or prefixing the filename
-path with @code{$SYSROOT}.  See also the description of @samp{-L} in
-@ref{Options,,Command-line Options}.
+for in the @dfn{sysroot prefix}.  The @dfn{sysroot prefix} can also be forced by specifying
+@code{=} as the first character in the filename path, or prefixing the
+filename path with @code{$SYSROOT}. See also the description of
+@samp{-L} in @ref{Options,,Command-line Options}.
+
+If a @dfn{sysroot prefix} is not used then the linker will try to open
+the file in the directory containing the linker script.  If it is not
+found the linker will then search the current directory.  If it is still
+not found the linker will search through the archive library search
+path.
 
 If you use @samp{INPUT (-l@var{file})}, @command{ld} will transform the
 name to @code{lib@var{file}.a}, as with the command-line argument