* readelf.c (get_machine_dlags): Add support for RX's PID mode.

	* ld-scripts/phdrs.exp: Expect to fail for the RX.

	* elf32-rx.c: Add support for PID mode.
	(rx_elf_relocate_section): Add checks for unsafe PID relocations.
	Include addend in R_RX_SYM relocations.

	* config/rx-defs.h (rx_pid_register): New.
	(rx_gp_register): New.
	* config/rx-parse.y (rx_lex): Add support for %gpreg and %pidreg.
	(displacement): Add PID support.
	* config/tc-rx.c (rx_pid_mode): New.
	(rx_num_int_regs): New.
	(rx_pid_register): New.
	(rx_gp_register): New.
	(options): Add -mpid and -mint-register= options.
	(md_longopts): Likewise.
	(md_parse_option): Likewise.
	(md_show_usage): Likewise.
	(rx_pid_symbol): New.
	(rx_pidreg_symbol): New.
	(rx_gpreg_symbol): New.
	(md_begin): Support PID.
	(rx_validate_fix_sub): Support PID.
	(tc_gen_reloc): Support PID.
	* doc/c-rx.texi: Document PID support.

	* rx.h (E_FLAG_RX_PID): New.

1 files changed, 44 insertions, 7 deletions

diff --git a/gas/doc/c-rx.texi b/gas/doc/c-rx.texi
index 183fbe385eb..cb89bd66c27 100644
--- a/gas/doc/c-rx.texi
+++ b/gas/doc/c-rx.texi
@@ -74,11 +74,25 @@ This is the default.
 @item -msmall-data-limit
 This option tells the assembler that the small data limit feature of
 the RX port of GCC is being used.  This results in the assembler
-generating an undefined reference to a symbol called __gp for use by
-the relocations that are needed to support the small data limit
+generating an undefined reference to a symbol called @code{__gp} for
+use by the relocations that are needed to support the small data limit
 feature.   This option is not enabled by default as it would otherwise
 pollute the symbol table.
 
+@cindex @samp{-mpid}
+@item -mpid
+This option tells the assembler that the position independent data of the
+RX port of GCC is being used.  This results in the assembler
+generating an undefined reference to a symbol called @code{__pid_base},
+and also setting the RX_PID flag bit in the e_flags field of the ELF
+header of the object file.
+
+@cindex @samp{-mint-register}
+@item -mint-register=@var{num}
+This option tells the assembler how many registers have been reserved
+for use by interrupt handlers.  This is needed in order to compute the
+correct values for the @code{%gpreg} and @code{%pidreg} meta registers.
+
 @end table
 
 @node RX-Modifiers
@@ -86,22 +100,45 @@ pollute the symbol table.
 
 @cindex RX modifiers
 @cindex syntax, RX
+@cindex %gp
 
-The assembler supports several modifiers when using symbol addresses
+The assembler supports one modifier when using symbol addresses
 in RX instruction operands.  The general syntax is the following:
 
 @smallexample
-%modifier(symbol)
+%gp(symbol)
 @end smallexample
 
+The modifier returns the offset from the @var{__gp} symbol to the
+specified symbol as a 16-bit value.  The intent is that this offset
+should be used in a register+offset move instruction when generating
+references to small data.  Ie, like this:
+
+@smallexample
+  mov.W	 %gp(_foo)[%gpreg], r1
+@end smallexample
+
+The assembler also supports two meta register names which can be used
+to refer to registers whose values may not be known to the
+programmer.  These meta register names are:
+
 @table @code
-@cindex symbol modifiers
 
-@item %gp
-@c FIXME: Add documentation here.
+@cindex @samp{%gpreg}
+@item %gpreg
+The small data address register.
+
+@cindex @samp{%pidreg}
+@item %pidreg
+The PID base address register.
 
 @end table
 
+Both registers normally have the value r13, but this can change if
+some registers have been reserved for use by interrupt handlers or if
+both the small data limit and position independent data features are
+being used at the same time.
+
 @node RX-Directives
 @section Assembler Directives