[PATCH] Add NetBSD/aarch64 gdbserver support

[Kamil Rytarowski <n54@gmx.com>]

The support is on par with NetBSD/amd64, thus GPR works,
single step and software breakpoint are operational, and the
SVR4 r_debug integration is functional.

gdbserver/ChangeLog:

        * netbsd-aarch64-low.cc: Add.
        * Makefile.in (SFILES): Register "netbsd-aarch64-low.c".
        * configure.srv: Add aarch64*-*-netbsd*.
---
 gdbserver/ChangeLog             |   6 ++
 gdbserver/Makefile.in           |   1 +
 gdbserver/configure.srv         |   6 ++
 gdbserver/netbsd-aarch64-low.cc | 113 ++++++++++++++++++++++++++++++++
 4 files changed, 126 insertions(+)
 create mode 100644 gdbserver/netbsd-aarch64-low.cc

diff --git a/gdbserver/ChangeLog b/gdbserver/ChangeLog
index d667a203e67..5fd71b6ee71 100644
--- a/gdbserver/ChangeLog
+++ b/gdbserver/ChangeLog
@@ -1,3 +1,9 @@
+2020-10-01  Kamil Rytarowski  <n54@gmx.com>
+
+	* netbsd-aarch64-low.cc: Add.
+	* Makefile.in (SFILES): Register "netbsd-aarch64-low.c".
+	* configure.srv: Add aarch64*-*-netbsd*.
+
 2020-10-01  Kamil Rytarowski  <n54@gmx.com>

 	* netbsd-i386-low.cc: Add.
diff --git a/gdbserver/Makefile.in b/gdbserver/Makefile.in
index 8b80acebdf1..442a34b381f 100644
--- a/gdbserver/Makefile.in
+++ b/gdbserver/Makefile.in
@@ -193,6 +193,7 @@ SFILES = \
 	$(srcdir)/linux-x86-low.cc \
 	$(srcdir)/linux-xtensa-low.cc \
 	$(srcdir)/mem-break.cc \
+	$(srcdir)/netbsd-aarch64-low.cc \
 	$(srcdir)/netbsd-amd64-low.cc \
 	$(srcdir)/netbsd-i386-low.cc \
 	$(srcdir)/netbsd-low.cc \
diff --git a/gdbserver/configure.srv b/gdbserver/configure.srv
index c4fe4ca81ee..cd25b1574e0 100644
--- a/gdbserver/configure.srv
+++ b/gdbserver/configure.srv
@@ -61,6 +61,12 @@ case "${gdbserver_host}" in
 			ipa_obj="${ipa_obj} linux-aarch64-tdesc-ipa.o"
 			ipa_obj="${ipa_obj} arch/aarch64-ipa.o"
 			;;
+  aarch64*-*-netbsd*)	srv_regobj=""
+			srv_tgtobj="netbsd-low.o netbsd-aarch64-low.o fork-child.o"
+			srv_tgtobj="${srv_tgtobj} nat/fork-inferior.o"
+			srv_tgtobj="${srv_tgtobj} nat/netbsd-nat.o"
+			srv_tgtobj="${srv_tgtobj} arch/aarch64-insn.o arch/aarch64.o"
+			;;
   arm*-*-linux*)	srv_tgtobj="$srv_linux_obj linux-arm-low.o"
 			srv_tgtobj="$srv_tgtobj linux-arm-tdesc.o"
 			srv_tgtobj="$srv_tgtobj linux-aarch32-low.o"
diff --git a/gdbserver/netbsd-aarch64-low.cc b/gdbserver/netbsd-aarch64-low.cc
new file mode 100644
index 00000000000..d0e485649d9
--- /dev/null
+++ b/gdbserver/netbsd-aarch64-low.cc
@@ -0,0 +1,113 @@
+/* Copyright (C) 2020 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 <sys/types.h>
+#include <sys/ptrace.h>
+#include <limits.h>
+
+#include "server.h"
+#include "netbsd-low.h"
+#include "arch/aarch64.h"
+#include "arch/aarch64-insn.h"
+#include "tdesc.h"
+
+/* The fill_function for the general-purpose register set.  */
+
+static void
+netbsd_aarch64_fill_gregset (struct regcache *regcache, char *buf)
+{
+  struct reg *r = (struct reg *) buf;
+
+#define netbsd_aarch64_collect_gp(regnum, fld) do {		\
+    collect_register (regcache, regnum, &r->fld);		\
+  } while (0)
+
+  for (size_t i = 0; i < 31; i++)
+    netbsd_aarch64_collect_gp (AARCH64_X0_REGNUM + i, r_reg[i]);
+
+  netbsd_aarch64_collect_gp (AARCH64_SP_REGNUM, r_sp);
+  netbsd_aarch64_collect_gp (AARCH64_PC_REGNUM, r_pc);
+}
+
+/* The store_function for the general-purpose register set.  */
+
+static void
+netbsd_aarch64_store_gregset (struct regcache *regcache, const char *buf)
+{
+  struct reg *r = (struct reg *) buf;
+
+#define netbsd_aarch64_supply_gp(regnum, fld) do {		\
+    supply_register (regcache, regnum, &r->fld);		\
+  } while(0)
+
+  for (size_t i = 0; i < 31; i++)
+    netbsd_aarch64_supply_gp (AARCH64_X0_REGNUM + i, r_reg[i]);
+
+  netbsd_aarch64_supply_gp (AARCH64_SP_REGNUM, r_sp);
+  netbsd_aarch64_supply_gp (AARCH64_PC_REGNUM, r_pc);
+}
+
+/* Description of all the aarch64-netbsd register sets.  */
+
+static const struct netbsd_regset_info netbsd_target_regsets[] =
+{
+  /* General Purpose Registers.  */
+  {PT_GETREGS, PT_SETREGS, sizeof (struct reg),
+  netbsd_aarch64_fill_gregset, netbsd_aarch64_store_gregset},
+  /* End of list marker.  */
+  {0, 0, -1, NULL, NULL }
+};
+
+/* NetBSD target op definitions for the aarch64 architecture.  */
+
+class netbsd_aarch64_target : public netbsd_process_target
+{
+protected:
+  const netbsd_regset_info *get_regs_info () override;
+
+  void low_arch_setup () override;
+};
+
+/* Return the information to access registers.  */
+
+const netbsd_regset_info *
+netbsd_aarch64_target::get_regs_info ()
+{
+  return netbsd_target_regsets;
+}
+
+/* Architecture-specific setup for the current process.  */
+
+void
+netbsd_aarch64_target::low_arch_setup ()
+{
+  target_desc *tdesc
+    = aarch64_create_target_description (0, false);
+
+  static const char *expedite_regs_aarch64[] = { "x29", "sp", "pc", NULL };
+  init_target_desc (tdesc, expedite_regs_aarch64);
+
+  current_process ()->tdesc = tdesc;
+}
+
+/* The singleton target ops object.  */
+
+static netbsd_aarch64_target the_netbsd_aarch64_target;
+
+/* The NetBSD target ops object.  */
+
+netbsd_process_target *the_netbsd_target = &the_netbsd_aarch64_target;
--
2.28.0