Add NetBSD/i386 gdbserver support

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

gdbserver/ChangeLog:

	* netbsd-i386-low.cc: Add.
	* Makefile.in (SFILES): Register "netbsd-i386-low.c".
	* configure.srv: Add i[34567]86-*-netbsd*.

4 files changed, 170 insertions, 0 deletions

diff --git a/gdbserver/ChangeLog b/gdbserver/ChangeLog
index 383e3d3..d667a20 100644
--- a/gdbserver/ChangeLog
+++ b/gdbserver/ChangeLog
@@ -1,5 +1,11 @@
 2020-10-01  Kamil Rytarowski  <n54@gmx.com>
 
+	* netbsd-i386-low.cc: Add.
+	* Makefile.in (SFILES): Register "netbsd-i386-low.c".
+	* configure.srv: Add i[34567]86-*-netbsd*.
+
+2020-10-01  Kamil Rytarowski  <n54@gmx.com>
+
 	* netbsd-amd64-low.cc (netbsd_x86_64_arch_setup): Remove.
 	(netbsd_target_regsets): Now const.
 	(the_low_target): Remove.
diff --git a/gdbserver/Makefile.in b/gdbserver/Makefile.in
index b0bad0c..8b80ace 100644
--- a/gdbserver/Makefile.in
+++ b/gdbserver/Makefile.in
@@ -194,6 +194,7 @@ SFILES = \
 	$(srcdir)/linux-xtensa-low.cc \
 	$(srcdir)/mem-break.cc \
 	$(srcdir)/netbsd-amd64-low.cc \
+	$(srcdir)/netbsd-i386-low.cc \
 	$(srcdir)/netbsd-low.cc \
 	$(srcdir)/netbsd-low.h \
 	$(srcdir)/proc-service.cc \
diff --git a/gdbserver/configure.srv b/gdbserver/configure.srv
index b9a3703..c4fe4ca 100644
--- a/gdbserver/configure.srv
+++ b/gdbserver/configure.srv
@@ -101,6 +101,12 @@ case "${gdbserver_host}" in
 			srv_tgtobj="${srv_tgtobj} arch/i386.o"
 			srv_mingw=yes
 			;;
+  i[34567]86-*-netbsd*)	srv_regobj=""
+			srv_tgtobj="netbsd-low.o netbsd-i386-low.o fork-child.o"
+			srv_tgtobj="${srv_tgtobj} nat/fork-inferior.o"
+			srv_tgtobj="${srv_tgtobj} nat/netbsd-nat.o"
+			srv_tgtobj="${srv_tgtobj} arch/i386.o"
+			;;
   ia64-*-linux*)	srv_regobj=reg-ia64.o
 			srv_tgtobj="$srv_linux_obj linux-ia64-low.o"
 			srv_linux_usrregs=yes
diff --git a/gdbserver/netbsd-i386-low.cc b/gdbserver/netbsd-i386-low.cc
new file mode 100644
index 0000000..e52fde2
--- /dev/null
+++ b/gdbserver/netbsd-i386-low.cc
@@ -0,0 +1,157 @@
+/* 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 "gdbsupport/x86-xstate.h"
+#include "arch/i386.h"
+#include "x86-tdesc.h"
+#include "tdesc.h"
+
+/* The index of various registers inside the regcache.  */
+
+enum netbsd_i386_gdb_regnum
+{
+  I386_EAX_REGNUM,              /* %eax */
+  I386_ECX_REGNUM,              /* %ecx */
+  I386_EDX_REGNUM,              /* %edx */
+  I386_EBX_REGNUM,              /* %ebx */
+  I386_ESP_REGNUM,              /* %esp */
+  I386_EBP_REGNUM,              /* %ebp */
+  I386_ESI_REGNUM,              /* %esi */
+  I386_EDI_REGNUM,              /* %edi */
+  I386_EIP_REGNUM,              /* %eip */
+  I386_EFLAGS_REGNUM,           /* %eflags */
+  I386_CS_REGNUM,               /* %cs */
+  I386_SS_REGNUM,               /* %ss */
+  I386_DS_REGNUM,               /* %ds */
+  I386_ES_REGNUM,               /* %es */
+  I386_FS_REGNUM,               /* %fs */
+  I386_GS_REGNUM,               /* %gs */
+  I386_ST0_REGNUM               /* %st(0) */
+};
+
+/* The fill_function for the general-purpose register set.  */
+
+static void
+netbsd_i386_fill_gregset (struct regcache *regcache, char *buf)
+{
+  struct reg *r = (struct reg *) buf;
+
+#define netbsd_i386_collect_gp(regnum, fld) do {		\
+    collect_register (regcache, regnum, &r->r_##fld);		\
+  } while (0)
+
+  netbsd_i386_collect_gp (I386_EAX_REGNUM, eax);
+  netbsd_i386_collect_gp (I386_EBX_REGNUM, ebx);
+  netbsd_i386_collect_gp (I386_ECX_REGNUM, ecx);
+  netbsd_i386_collect_gp (I386_EDX_REGNUM, edx);
+  netbsd_i386_collect_gp (I386_ESP_REGNUM, esp);
+  netbsd_i386_collect_gp (I386_EBP_REGNUM, ebp);
+  netbsd_i386_collect_gp (I386_ESI_REGNUM, esi);
+  netbsd_i386_collect_gp (I386_EDI_REGNUM, edi);
+  netbsd_i386_collect_gp (I386_EIP_REGNUM, eip);
+  netbsd_i386_collect_gp (I386_EFLAGS_REGNUM, eflags);
+  netbsd_i386_collect_gp (I386_CS_REGNUM, cs);
+  netbsd_i386_collect_gp (I386_SS_REGNUM, ss);
+  netbsd_i386_collect_gp (I386_DS_REGNUM, ds);
+  netbsd_i386_collect_gp (I386_ES_REGNUM, es);
+  netbsd_i386_collect_gp (I386_FS_REGNUM, fs);
+  netbsd_i386_collect_gp (I386_GS_REGNUM, gs);
+}
+
+/* The store_function for the general-purpose register set.  */
+
+static void
+netbsd_i386_store_gregset (struct regcache *regcache, const char *buf)
+{
+  struct reg *r = (struct reg *) buf;
+
+#define netbsd_i386_supply_gp(regnum, fld) do {		\
+    supply_register (regcache, regnum, &r->r_##fld);	\
+  } while(0)
+
+  netbsd_i386_supply_gp (I386_EAX_REGNUM, eax);
+  netbsd_i386_supply_gp (I386_EBX_REGNUM, ebx);
+  netbsd_i386_supply_gp (I386_ECX_REGNUM, ecx);
+  netbsd_i386_supply_gp (I386_EDX_REGNUM, edx);
+  netbsd_i386_supply_gp (I386_ESP_REGNUM, esp);
+  netbsd_i386_supply_gp (I386_EBP_REGNUM, ebp);
+  netbsd_i386_supply_gp (I386_ESI_REGNUM, esi);
+  netbsd_i386_supply_gp (I386_EDI_REGNUM, edi);
+  netbsd_i386_supply_gp (I386_EIP_REGNUM, eip);
+  netbsd_i386_supply_gp (I386_EFLAGS_REGNUM, eflags);
+  netbsd_i386_supply_gp (I386_CS_REGNUM, cs);
+  netbsd_i386_supply_gp (I386_SS_REGNUM, ss);
+  netbsd_i386_supply_gp (I386_DS_REGNUM, ds);
+  netbsd_i386_supply_gp (I386_ES_REGNUM, es);
+  netbsd_i386_supply_gp (I386_FS_REGNUM, fs);
+  netbsd_i386_supply_gp (I386_GS_REGNUM, gs);
+}
+
+/* Description of all the x86-netbsd register sets.  */
+
+static const struct netbsd_regset_info netbsd_target_regsets[] =
+{
+  /* General Purpose Registers.  */
+  {PT_GETREGS, PT_SETREGS, sizeof (struct reg),
+  netbsd_i386_fill_gregset, netbsd_i386_store_gregset},
+  /* End of list marker.  */
+  {0, 0, -1, NULL, NULL }
+};
+
+/* NetBSD target op definitions for the amd64 architecture.  */
+
+class netbsd_i386_target : public netbsd_process_target
+{
+public:
+  const netbsd_regset_info *get_regs_info () override;
+
+  void low_arch_setup () override;
+};
+
+const netbsd_regset_info *
+netbsd_i386_target::get_regs_info ()
+{
+  return netbsd_target_regsets;
+}
+
+/* Initialize the target description for the architecture of the
+   inferior.  */
+
+void
+netbsd_i386_target::low_arch_setup ()
+{
+  target_desc *tdesc
+    = i386_create_target_description (X86_XSTATE_SSE_MASK, false, false);
+
+  init_target_desc (tdesc, i386_expedite_regs);
+
+  current_process ()->tdesc = tdesc;
+}
+
+/* The singleton target ops object.  */
+
+static netbsd_i386_target the_netbsd_i386_target;
+
+/* The NetBSD target ops object.  */
+
+netbsd_process_target *the_netbsd_target = &the_netbsd_i386_target;