2013-05-06 Sandra Loosemore <sandra@codesourcery.com>

	    Andrew Jenner  <andrew@codesourcery.com>

	gdb/gdbserver/
	* Makefile.in (SFILES): Add linux-nios2-low.c.
	(clean): Add action to delete nios2-linux.c.
	(nios2-linux.c): New rule.
	* configure.srv: Add nios2*-*-linux*.
	* linux-nios2-low.c: New.

1 files changed, 234 insertions, 0 deletions

diff --git a/gdb/gdbserver/linux-nios2-low.c b/gdb/gdbserver/linux-nios2-low.c
new file mode 100644
index 0000000..c41579f
--- /dev/null
+++ b/gdb/gdbserver/linux-nios2-low.c
@@ -0,0 +1,234 @@
+/* GNU/Linux/Nios II specific low level interface, for the remote server for
+   GDB.
+   Copyright (C) 2008-2013 Free Software Foundation, Inc.
+
+   Contributed by Mentor Graphics, 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 "server.h"
+#include "linux-low.h"
+#include <sys/ptrace.h>
+#include <endian.h>
+#include "gdb_proc_service.h"
+#include <asm/ptrace.h>
+
+#ifndef PTRACE_GET_THREAD_AREA
+#define PTRACE_GET_THREAD_AREA 25
+#endif
+
+/* The following definition must agree with the number of registers
+   defined in "struct user_regs" in GLIBC
+   (ports/sysdeps/unix/sysv/linux/nios2/sys/user.h), and also with
+   NIOS2_NUM_REGS in GDB proper.  */
+
+#define nios2_num_regs 49
+
+/* Defined in auto-generated file nios2-linux.c.  */
+
+void init_registers_nios2_linux (void);
+
+/* This union is used to convert between int and byte buffer
+   representations of register contents.  */
+
+union nios2_register
+{
+  unsigned char buf[4];
+  int reg32;
+};
+
+/* Return the ptrace ``address'' of register REGNO. */
+
+static int nios2_regmap[] = {
+  -1,  1,  2,  3,  4,  5,  6,  7,
+  8,  9,  10, 11, 12, 13, 14, 15,
+  16, 17, 18, 19, 20, 21, 22, 23,
+  24, 25, 26, 27, 28, 29, 30, 31,
+  32, 33, 34, 35, 36, 37, 38, 39,
+  40, 41, 42, 43, 44, 45, 46, 47,
+  48,
+  0
+};
+
+/* Implement the arch_setup linux_target_ops method.  */
+
+static void
+nios2_arch_setup (void)
+{
+  init_registers_nios2_linux ();
+}
+
+/* Implement the cannot_fetch_register linux_target_ops method.  */
+
+static int
+nios2_cannot_fetch_register (int regno)
+{
+  if (nios2_regmap[regno] == -1)
+    return 1;
+
+  return 0;
+}
+
+/* Implement the cannot_store_register linux_target_ops method.  */
+
+static int
+nios2_cannot_store_register (int regno)
+{
+  if (nios2_regmap[regno] == -1)
+    return 1;
+
+  return 0;
+}
+
+/* Implement the get_pc linux_target_ops method.  */
+
+static CORE_ADDR
+nios2_get_pc (struct regcache *regcache)
+{
+  union nios2_register pc;
+
+  collect_register_by_name (regcache, "pc", pc.buf);
+  return pc.reg32;
+}
+
+/* Implement the set_pc linux_target_ops method.  */
+
+static void
+nios2_set_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+  union nios2_register newpc;
+
+  newpc.reg32 = pc;
+  supply_register_by_name (regcache, "pc", newpc.buf);
+}
+
+/* Breakpoint support.  */
+
+static const unsigned int nios2_breakpoint = 0x003b6ffa;
+#define nios2_breakpoint_len 4
+
+/* Implement the breakpoint_reinsert_addr linux_target_ops method.  */
+
+static CORE_ADDR
+nios2_reinsert_addr (void)
+{
+  union nios2_register ra;
+  struct regcache *regcache = get_thread_regcache (current_inferior, 1);
+
+  collect_register_by_name (regcache, "ra", ra.buf);
+  return ra.reg32;
+}
+
+/* Implement the breakpoint_at linux_target_ops method.  */
+
+static int
+nios2_breakpoint_at (CORE_ADDR where)
+{
+  unsigned int insn;
+
+  (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
+  if (insn == nios2_breakpoint)
+    return 1;
+  return 0;
+}
+
+/* Fetch the thread-local storage pointer for libthread_db.  */
+
+ps_err_e
+ps_get_thread_area (const struct ps_prochandle *ph,
+                    lwpid_t lwpid, int idx, void **base)
+{
+  if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
+    return PS_ERR;
+
+  /* IDX is the bias from the thread pointer to the beginning of the
+     thread descriptor.  It has to be subtracted due to implementation
+     quirks in libthread_db.  */
+  *base = (void *) ((char *) *base - idx);
+
+  return PS_OK;
+}
+
+#ifdef HAVE_PTRACE_GETREGS
+
+/* Helper functions to collect/supply a single register REGNO.  */
+
+static void
+nios2_collect_register (struct regcache *regcache, int regno,
+			union nios2_register *reg)
+{
+  union nios2_register tmp_reg;
+
+  collect_register (regcache, regno, &tmp_reg.reg32);
+  reg->reg32 = tmp_reg.reg32;
+}
+
+static void
+nios2_supply_register (struct regcache *regcache, int regno,
+		       const union nios2_register *reg)
+{
+  supply_register (regcache, regno, reg->buf);
+}
+
+/* We have only a single register set on Nios II.  */
+
+static void
+nios2_fill_gregset (struct regcache *regcache, void *buf)
+{
+  union nios2_register *regset = buf;
+  int i;
+
+  for (i = 1; i < nios2_num_regs; i++)
+    nios2_collect_register (regcache, i, regset + i);
+}
+
+static void
+nios2_store_gregset (struct regcache *regcache, const void *buf)
+{
+  const union nios2_register *regset = buf;
+  int i;
+
+  for (i = 0; i < nios2_num_regs; i++)
+    nios2_supply_register (regcache, i, regset + i);
+}
+#endif /* HAVE_PTRACE_GETREGS */
+
+struct regset_info target_regsets[] =
+{
+#ifdef HAVE_PTRACE_GETREGS
+  { PTRACE_GETREGS, PTRACE_SETREGS, 0, nios2_num_regs * 4, GENERAL_REGS,
+    nios2_fill_gregset, nios2_store_gregset },
+#endif /* HAVE_PTRACE_GETREGS */
+  { 0, 0, 0, -1, -1, NULL, NULL }
+};
+
+struct linux_target_ops the_low_target =
+{
+  nios2_arch_setup,
+  nios2_num_regs,
+  nios2_regmap,
+  NULL,
+  nios2_cannot_fetch_register,
+  nios2_cannot_store_register,
+  NULL,
+  nios2_get_pc,
+  nios2_set_pc,
+  (const unsigned char *) &nios2_breakpoint,
+  nios2_breakpoint_len,
+  nios2_reinsert_addr,
+  0,
+  nios2_breakpoint_at,
+};