Add support for the C_SKY series of processors.

This patch series is a new binutils port for C-SKY processors, including support for both the V1 and V2 processor variants.  V1 is derived from the MCore architecture while V2 is substantially different, with mixed 16- and 32-bit instructions, a larger register set, a different (but overlapping) ABI, etc.  There is support for bare-metal ELF targets and Linux with both glibc and uClibc.

This code is being contributed jointly by C-SKY Microsystems and Mentor Graphics.  C-SKY is responsible for the technical content and has proposed Lifang Xia and Yunhai Shang as port maintainers.  (Note that C-SKY does have a corporate copyright assignment on file with the FSF.) Mentor Graphics' role has been cleaning up the code, adding documentation and additional test cases, etc, to address issues we anticipated reviewers would complain about.

bfd     * Makefile.am (ALL_MACHINES, ALL_MACHINES_CFILES): Add C-SKY.
        (BFD32_BACKENDS, BFD_BACKENDS_CFILES): Likewise.
        * Makefile.in: Regenerated.
        * archures.c (enum bfd_architecture): Add bfd_arch_csky and
        related bfd_mach defines.
        (bfd_csky_arch): Declare.
        (bfd_archures_list): Add C-SKY.
        * bfd-in.h (elf32_csky_build_stubs): Declare.
        (elf32_csky_size_stubs): Declare.
        (elf32_csky_next_input_section: Declare.
        (elf32_csky_setup_section_lists): Declare.
        * bfd-in2.h: Regenerated.
        * config.bfd: Add C-SKY.
        * configure.ac: Likewise.
        * configure: Regenerated.
        * cpu-csky.c: New file.
        * elf-bfd.h (enum elf_target_id): Add C-SKY.
        * elf32-csky.c: New file.
        * libbfd.h: Regenerated.
        * reloc.c: Add C-SKY relocations.
        * targets.c (csky_elf32_be_vec, csky_elf32_le_vec): Declare.
        (_bfd_target_vector): Add C-SKY target vector entries.

binutils* readelf.c: Include elf/csky.h.
        (guess_is_rela): Handle EM_CSKY.
        (dump_relocations): Likewise.
        (get_machine_name): Likewise.
        (is_32bit_abs_reloc): Likewise.

include  * dis-asm.h (csky_symbol_is_valid): Declare.
         * opcode/csky.h: New file.

opcodes  * Makefile.am (TARGET_LIBOPCODES_CFILES): Add csky-dis.c.
         * Makefile.in: Regenerated.
         * configure.ac: Add C-SKY.
         * configure: Regenerated.
         * csky-dis.c: New file.
         * csky-opc.h: New file.
         * disassemble.c (ARCH_csky): Define.
         (disassembler, disassemble_init_for_target): Add case for ARCH_csky.
         * disassemble.h (print_insn_csky, csky_get_disassembler): Declare.

gas      * Makefile.am (TARGET_CPU_CFILES): Add entry for C-SKY.
         (TARGET_CPU_HFILES, TARGET_ENV_HFILES): Likewise.
         * Makefile.in: Regenerated.
         * config/tc-csky.c: New file.
         * config/tc-csky.h: New file.
         * config/te-csky_abiv1.h: New file.
         * config/te-csky_abiv1_linux.h: New file.
         * config/te-csky_abiv2.h: New file.
         * config/te-csky_abiv2_linux.h: New file.
         * configure.tgt: Add C-SKY.
         * doc/Makefile.am (CPU_DOCS): Add entry for C-SKY.
         * doc/Makefile.in: Regenerated.
         * doc/all.texi: Set CSKY feature.
         * doc/as.texi (Overview): Add C-SKY options.
         (Machine Dependencies): Likewise.
         * doc/c-csky.texi: New file.
         * testsuite/gas/csky/*: New test cases.

ld      * Makefile.am (ALL_EMULATION_SOURCES): Add C-SKY emulations.
        (ecskyelf.c, ecskyelf_linux.c): New rules.
        * Makefile.in: Regenerated.
        * configure.tgt: Add C-SKY.
        * emulparams/cskyelf.sh: New file.
        * emulparams/cskyelf_linux.sh: New file.
        * emultempl/cskyelf.em: New file.
        * gen-doc.texi: Add C-SKY.
        * ld.texi: Likewise.
        (Options specific to C-SKY targets): New section.
        * testsuite/ld-csky/*: New tests.

1 files changed, 31 insertions, 0 deletions

diff --git a/ld/ld.texi b/ld/ld.texi
index b9fe232..75a7430 100644
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -21,6 +21,7 @@
 @set GENERIC
 @set ARM
 @set C6X
+@set CSKY
 @set H8300
 @set HPPA
 @set M68HC11
@@ -3008,6 +3009,36 @@ exidx entries in frame unwind info.
 @c man end
 @end ifset
 
+@ifset CSKY
+@subsection Options specific to C-SKY targets
+
+@c man begin OPTIONS
+
+@table @gcctabopt
+
+@kindex --branch-stub on C-SKY
+@item --branch-stub
+This option enables linker branch relaxation by inserting branch stub
+sections when needed to extend the range of branches.  This option is
+usually not required since C-SKY supports branch and call instructions that
+can access the full memory range and branch relaxation is normally handled by
+the compiler or assembler.
+
+@kindex --stub-group-size on C-SKY
+@item --stub-group-size=@var{N}
+This option allows finer control of linker branch stub creation.
+It sets the maximum size of a group of input sections that can
+be handled by one stub section.  A negative value of @var{N} locates
+stub sections after their branches, while a positive value allows stub
+sections to appear either before or after the branches.  Values of
+@samp{1} or @samp{-1} indicate that the
+linker should choose suitable defaults.
+
+@end table
+
+@c man end
+@end ifset
+
 @ifset M68HC11
 @subsection Options specific to Motorola 68HC11 and 68HC12 targets