Add FreeBSD/aarch64 architecture.

Support for collecting and supplying general purpose and floating point
register sets is provided along with signal frame unwinding.

gdb/ChangeLog:

	* Makefile.in (ALL_64_TARGET_OBS): Add aarch64-fbsd-tdep.o.
	(ALLDEPFILES): Add aarch64-fbsd-tdep.c.
	* NEWS: Mention new FreeBSD/aarch64 target.
	* configure.tgt: Add aarch64*-*-freebsd*.
	* aarch64-fbsd-tdep.c: New file.
	* aarch64-fbsd-tdep.h: New file.

1 files changed, 205 insertions, 0 deletions

diff --git a/gdb/aarch64-fbsd-tdep.c b/gdb/aarch64-fbsd-tdep.c
new file mode 100644
index 0000000000..4d0b44f379
--- /dev/null
+++ b/gdb/aarch64-fbsd-tdep.c
@@ -0,0 +1,205 @@
+/* Target-dependent code for FreeBSD/aarch64.
+
+   Copyright (C) 2017 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+
+#include "gdbarch.h"
+#include "fbsd-tdep.h"
+#include "aarch64-tdep.h"
+#include "aarch64-fbsd-tdep.h"
+#include "osabi.h"
+#include "solib-svr4.h"
+#include "target.h"
+#include "tramp-frame.h"
+#include "trad-frame.h"
+
+/* In a signal frame, sp points to a 'struct sigframe' which is
+   defined as:
+
+   struct sigframe {
+	   siginfo_t	sf_si;
+	   ucontext_t	sf_uc;
+   };
+
+   ucontext_t is defined as:
+
+   struct __ucontext {
+	   sigset_t	uc_sigmask;
+	   mcontext_t	uc_mcontext;
+	   ...
+   };
+
+   The mcontext_t contains the general purpose register set followed
+   by the floating point register set.  The floating point register
+   set is only valid if the _MC_FP_VALID flag is set in mc_flags.  */
+
+#define AARCH64_MCONTEXT_REG_SIZE               8
+#define AARCH64_MCONTEXT_FPREG_SIZE             16
+#define AARCH64_SIGFRAME_UCONTEXT_OFFSET	80
+#define AARCH64_UCONTEXT_MCONTEXT_OFFSET	16
+#define	AARCH64_MCONTEXT_FPREGS_OFFSET		272
+#define	AARCH64_MCONTEXT_FLAGS_OFFSET		800
+#define AARCH64_MCONTEXT_FLAG_FP_VALID		0x1
+
+/* Implement the "init" method of struct tramp_frame.  */
+
+static void
+aarch64_fbsd_sigframe_init (const struct tramp_frame *self,
+			     struct frame_info *this_frame,
+			     struct trad_frame_cache *this_cache,
+			     CORE_ADDR func)
+{
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
+  CORE_ADDR mcontext_addr =
+    sp
+    + AARCH64_SIGFRAME_UCONTEXT_OFFSET
+    + AARCH64_UCONTEXT_MCONTEXT_OFFSET;
+  gdb_byte buf[4];
+  int i;
+
+  for (i = 0; i < 30; i++)
+    {
+      trad_frame_set_reg_addr (this_cache,
+			       AARCH64_X0_REGNUM + i,
+			       mcontext_addr + i * AARCH64_MCONTEXT_REG_SIZE);
+    }
+  trad_frame_set_reg_addr (this_cache, AARCH64_LR_REGNUM,
+			   mcontext_addr + 30 * AARCH64_MCONTEXT_REG_SIZE);
+  trad_frame_set_reg_addr (this_cache, AARCH64_SP_REGNUM,
+			   mcontext_addr + 31 * AARCH64_MCONTEXT_REG_SIZE);
+  trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM,
+			   mcontext_addr + 32 * AARCH64_MCONTEXT_REG_SIZE);
+  trad_frame_set_reg_addr (this_cache, AARCH64_CPSR_REGNUM,
+			   mcontext_addr + 33 * AARCH64_MCONTEXT_REG_SIZE);
+
+  if (target_read_memory (mcontext_addr + AARCH64_MCONTEXT_FLAGS_OFFSET, buf,
+			  4) == 0
+      && (extract_unsigned_integer (buf, 4, byte_order)
+	  & AARCH64_MCONTEXT_FLAG_FP_VALID))
+    {
+      for (i = 0; i < 32; i++)
+	{
+	  trad_frame_set_reg_addr (this_cache, AARCH64_V0_REGNUM + i,
+				   mcontext_addr
+				   + AARCH64_MCONTEXT_FPREGS_OFFSET
+				   + i * AARCH64_MCONTEXT_FPREG_SIZE);
+	}
+      trad_frame_set_reg_addr (this_cache, AARCH64_FPSR_REGNUM,
+			       mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET
+			       + 32 * AARCH64_MCONTEXT_FPREG_SIZE);
+      trad_frame_set_reg_addr (this_cache, AARCH64_FPCR_REGNUM,
+			       mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET
+			       + 32 * AARCH64_MCONTEXT_FPREG_SIZE + 4);
+    }
+
+  trad_frame_set_id (this_cache, frame_id_build (sp, func));
+}
+
+static const struct tramp_frame aarch64_fbsd_sigframe =
+{
+  SIGTRAMP_FRAME,
+  4,
+  {
+    {0x910003e0, -1},		/* mov  x0, sp  */
+    {0x91014000, -1},		/* add  x0, x0, #SF_UC  */
+    {0xd2803428, -1},		/* mov  x8, #SYS_sigreturn  */
+    {0xd4000001, -1},		/* svc  0x0  */
+    {TRAMP_SENTINEL_INSN, -1}
+  },
+  aarch64_fbsd_sigframe_init
+};
+
+/* Register maps.  */
+
+static const struct regcache_map_entry aarch64_fbsd_gregmap[] =
+  {
+    { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
+    { 1, AARCH64_LR_REGNUM, 8 },
+    { 1, AARCH64_SP_REGNUM, 8 },
+    { 1, AARCH64_PC_REGNUM, 8 },
+    { 1, AARCH64_CPSR_REGNUM, 4 },
+    { 0 }
+  };
+
+static const struct regcache_map_entry aarch64_fbsd_fpregmap[] =
+  {
+    { 32, AARCH64_V0_REGNUM, 16 }, /* v0 ... v31 */
+    { 1, AARCH64_FPSR_REGNUM, 4 },
+    { 1, AARCH64_FPCR_REGNUM, 4 },
+    { 0 }
+  };
+
+/* Register set definitions.  */
+
+const struct regset aarch64_fbsd_gregset =
+  {
+    aarch64_fbsd_gregmap,
+    regcache_supply_regset, regcache_collect_regset
+  };
+
+const struct regset aarch64_fbsd_fpregset =
+  {
+    aarch64_fbsd_fpregmap,
+    regcache_supply_regset, regcache_collect_regset
+  };
+
+/* Implement the "regset_from_core_section" gdbarch method.  */
+
+static void
+aarch64_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
+					   iterate_over_regset_sections_cb *cb,
+					   void *cb_data,
+					   const struct regcache *regcache)
+{
+  cb (".reg", AARCH64_FBSD_SIZEOF_GREGSET, &aarch64_fbsd_gregset,
+      NULL, cb_data);
+  cb (".reg2", AARCH64_FBSD_SIZEOF_FPREGSET, &aarch64_fbsd_fpregset,
+      NULL, cb_data);
+}
+
+/* Implement the 'init_osabi' method of struct gdb_osabi_handler.  */
+
+static void
+aarch64_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  /* Generic FreeBSD support.  */
+  fbsd_init_abi (info, gdbarch);
+
+  set_solib_svr4_fetch_link_map_offsets (gdbarch,
+					 svr4_lp64_fetch_link_map_offsets);
+
+  tramp_frame_prepend_unwinder (gdbarch, &aarch64_fbsd_sigframe);
+
+  /* Enable longjmp.  */
+  tdep->jb_pc = 13;
+
+  set_gdbarch_iterate_over_regset_sections
+    (gdbarch, aarch64_fbsd_iterate_over_regset_sections);
+}
+
+void
+_initialize_aarch64_fbsd_tdep (void)
+{
+  gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_FREEBSD,
+			  aarch64_fbsd_init_abi);
+}