Add OpenBSD/m88k support.

* NEWS (New native configurations): Mention OpenBSD/m88k.
* m88k-tdep.c, m88k-tdep.h, m88kbsd-nat.c, config/m88k/nm-obsd.h,
config/m88k/obsd.mh, config/m88k/obsd.mt: New files.
* Makefile.in (m88k_tdep_h): New variable.
(ALLDEPFILES): Add m88k-tdep.c and m88kbsd-nat.c.
(m88kbsd-nat.o, m88k-tdep.o): New dependencies.
* configure.host: Add m88*-*-openbsd*.
* configure.tgt: Add m88*-*-openbsd*.

1 files changed, 897 insertions, 0 deletions

diff --git a/gdb/m88k-tdep.c b/gdb/m88k-tdep.c
new file mode 100644
index 0000000..42a702d
--- /dev/null
+++ b/gdb/m88k-tdep.c
@@ -0,0 +1,897 @@
+/* Target-dependent code for the Motorola 88000 series.
+
+   Copyright 2004 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 2 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, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include "defs.h"
+#include "arch-utils.h"
+#include "dis-asm.h"
+#include "frame.h"
+#include "frame-base.h"
+#include "frame-unwind.h"
+#include "gdbcore.h"
+#include "gdbtypes.h"
+#include "regcache.h"
+#include "regset.h"
+#include "symtab.h"
+#include "trad-frame.h"
+#include "value.h"
+
+#include "gdb_assert.h"
+#include "gdb_string.h"
+
+#include "m88k-tdep.h"
+
+/* Fetch the instruction at PC.  */
+
+static unsigned long
+m88k_fetch_instruction (CORE_ADDR pc)
+{
+  return read_memory_unsigned_integer (pc, 4);
+}
+
+/* Register information.  */
+
+/* Return the name of register REGNUM.  */
+
+static const char *
+m88k_register_name (int regnum)
+{
+  static char *register_names[] =
+  {
+    "r0",  "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
+    "r8",  "r9",  "r10", "r11", "r12", "r13", "r14", "r15",
+    "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
+    "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
+    "epsr", "fpsr", "fpcr", "sxip", "snip", "sfip"
+  };
+
+  if (regnum >= 0 && regnum < ARRAY_SIZE (register_names))
+    return register_names[regnum];
+
+  return NULL;
+}
+
+/* Return the GDB type object for the "standard" data type of data in
+   register REGNUM. */
+
+static struct type *
+m88k_register_type (struct gdbarch *gdbarch, int regnum)
+{
+  /* SXIP, SNIP, SFIP and R1 contain code addresses.  */
+  if ((regnum >= M88K_SXIP_REGNUM && regnum <= M88K_SFIP_REGNUM)
+      || regnum == M88K_R1_REGNUM)
+    return builtin_type_void_func_ptr;
+
+  /* R30 and R31 typically contains data addresses.  */
+  if (regnum == M88K_R30_REGNUM || regnum == M88K_R31_REGNUM)
+    return builtin_type_void_data_ptr;
+
+  return builtin_type_int32;
+}
+
+
+static CORE_ADDR
+m88k_addr_bits_remove (CORE_ADDR addr)
+{
+  /* All instructures are 4-byte aligned.  The lower 2 bits of SXIP,
+     SNIP and SFIP are used for special purposes: bit 0 is the
+     exception bit and bit 1 is the valid bit.  */
+  return addr & ~0x3;
+}
+
+/* Use the program counter to determine the contents and size of a
+   breakpoint instruction.  Return a pointer to a string of bytes that
+   encode a breakpoint instruction, store the length of the string in
+   *LEN and optionally adjust *PC to point to the correct memory
+   location for inserting the breakpoint.  */
+   
+static const unsigned char *
+m88k_breakpoint_from_pc (CORE_ADDR *pc, int *len)
+{
+  /* tb 0,r0,511 */
+  static unsigned char break_insn[] = { 0xf0, 0x00, 0xd1, 0xff };
+
+  *len = sizeof (break_insn);
+  return break_insn;
+}
+
+static CORE_ADDR
+m88k_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
+{
+  CORE_ADDR pc;
+
+  pc = frame_unwind_register_unsigned (next_frame, M88K_SXIP_REGNUM);
+  return m88k_addr_bits_remove (pc);
+}
+
+static void
+m88k_write_pc (CORE_ADDR pc, ptid_t ptid)
+{
+  /* According to the MC88100 RISC Microprocessor User's Manual,
+     section 6.4.3.1.2:
+
+     "... can be made to return to a particular instruction by placing
+     a valid instruction address in the SNIP and the next sequential
+     instruction address in the SFIP (with V bits set and E bits
+     clear).  The rte resumes execution at the instruction pointed to
+     by the SNIP, then the SFIP."
+
+     The E bit is the least significant bit (bit 0).  The V (valid)
+     bit is bit 1.  This is why we logical or 2 into the values we are
+     writing below.  It turns out that SXIP plays no role when
+     returning from an exception so nothing special has to be done
+     with it.  We could even (presumably) give it a totally bogus
+     value.  */
+
+  write_register_pid (M88K_SXIP_REGNUM, pc, ptid);
+  write_register_pid (M88K_SNIP_REGNUM, pc | 2, ptid);
+  write_register_pid (M88K_SFIP_REGNUM, (pc + 4) | 2, ptid);
+}
+
+
+/* The functions on this page are intended to be used to classify
+   function arguments.  */
+
+/* Check whether TYPE is "Integral or Pointer".  */
+
+static int
+m88k_integral_or_pointer_p (const struct type *type)
+{
+  switch (TYPE_CODE (type))
+    {
+    case TYPE_CODE_INT:
+    case TYPE_CODE_BOOL:
+    case TYPE_CODE_CHAR:
+    case TYPE_CODE_ENUM:
+    case TYPE_CODE_RANGE:
+      {
+	/* We have byte, half-word, word and extended-word/doubleword
+           integral types.  */
+	int len = TYPE_LENGTH (type);
+	return (len == 1 || len == 2 || len == 4 || len == 8);
+      }
+      return 1;
+    case TYPE_CODE_PTR:
+    case TYPE_CODE_REF:
+      {
+	/* Allow only 32-bit pointers.  */
+	return (TYPE_LENGTH (type) == 4);
+      }
+      return 1;
+    default:
+      break;
+    }
+
+  return 0;
+}
+
+/* Check whether TYPE is "Floating".  */
+
+static int
+m88k_floating_p (const struct type *type)
+{
+  switch (TYPE_CODE (type))
+    {
+    case TYPE_CODE_FLT:
+      {
+	int len = TYPE_LENGTH (type);
+	return (len == 4 || len == 8);
+      }
+    default:
+      break;
+    }
+
+  return 0;
+}
+
+/* Check whether TYPE is "Structure or Union".  */
+
+static int
+m88k_structure_or_union_p (const struct type *type)
+{
+  switch (TYPE_CODE (type))
+    {
+    case TYPE_CODE_STRUCT:
+    case TYPE_CODE_UNION:
+      return 1;
+    default:
+      break;
+    }
+
+  return 0;
+}
+
+/* Check whether TYPE has 8-byte alignment.  */
+
+static int
+m88k_8_byte_align_p (struct type *type)
+{
+  if (m88k_structure_or_union_p (type))
+    {
+      int i;
+
+      for (i = 0; i < TYPE_NFIELDS (type); i++)
+	{
+	  struct type *subtype = check_typedef (TYPE_FIELD_TYPE (type, i));
+
+	  if (m88k_8_byte_align_p (subtype))
+	    return 1;
+	}
+    }
+
+  if (m88k_integral_or_pointer_p (type) || m88k_floating_p (type))
+    return (TYPE_LENGTH (type) == 8);
+
+  return 0;
+}
+
+/* Check whether TYPE can be passed in a register.  */
+
+static int
+m88k_in_register_p (struct type *type)
+{
+  if (m88k_integral_or_pointer_p (type) || m88k_floating_p (type))
+    return 1;
+
+  if (m88k_structure_or_union_p (type) && TYPE_LENGTH (type) == 4)
+    return 1;
+
+  return 0;
+}
+
+static CORE_ADDR
+m88k_store_arguments (struct regcache *regcache, int nargs,
+		      struct value **args, CORE_ADDR sp)
+{
+  int num_register_words = 0;
+  int num_stack_words = 0;
+  int i;
+
+  for (i = 0; i < nargs; i++)
+    {
+      struct type *type = VALUE_TYPE (args[i]);
+      int len = TYPE_LENGTH (type);
+
+      if (m88k_integral_or_pointer_p (type) && len < 4)
+	{
+	  args[i] = value_cast (builtin_type_int32, args[i]);
+	  type = VALUE_TYPE (args[i]);
+	  len = TYPE_LENGTH (type);
+	}
+
+      if (m88k_in_register_p (type))
+	{
+	  int num_words = 0;
+
+	  if (num_register_words % 2 == 1 && m88k_8_byte_align_p (type))
+	    num_words++;
+
+	  num_words += ((len + 3) / 4);
+	  if (num_register_words + num_words <= 8)
+	    {
+	      num_register_words += num_words;
+	      continue;
+	    }
+
+	  /* We've run out of available registers.  Pass the argument
+             on the stack.  */
+	}
+
+      if (num_stack_words % 2 == 1 && m88k_8_byte_align_p (type))
+	num_stack_words++;
+
+      num_stack_words += ((len + 3) / 4);
+    }
+
+  /* Allocate stack space.  */
+  sp = align_down (sp - 32 - num_stack_words * 4, 16);
+  num_stack_words = num_register_words = 0;
+
+  for (i = 0; i < nargs; i++)
+    {
+      char *valbuf = VALUE_CONTENTS (args[i]);
+      struct type *type = VALUE_TYPE (args[i]);
+      int len = TYPE_LENGTH (type);
+      int stack_word = num_stack_words;
+
+      if (m88k_in_register_p (type))
+	{
+	  int register_word = num_register_words;
+
+	  if (register_word % 2 == 1 && m88k_8_byte_align_p (type))
+	    register_word++;
+
+	  gdb_assert (len == 4 || len == 8);
+
+	  if (register_word + len / 8 < 8)
+	    {
+	      int regnum = M88K_R2_REGNUM + register_word;
+
+	      regcache_raw_write (regcache, regnum, valbuf);
+	      if (len > 4)
+		regcache_raw_write (regcache, regnum + 1, valbuf + 4);
+
+	      num_register_words = (register_word + len / 4);
+	      continue;
+	    }
+	}
+
+      if (stack_word % 2 == -1 && m88k_8_byte_align_p (type))
+	stack_word++;
+
+      write_memory (sp + stack_word * 4, valbuf, len);
+      num_stack_words = (stack_word + (len + 3) / 4);
+    }
+
+  return sp;
+}
+
+static CORE_ADDR
+m88k_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr,
+		      struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
+		      struct value **args, CORE_ADDR sp, int struct_return,
+		      CORE_ADDR struct_addr)
+{
+  /* Set up the function arguments.  */
+  sp = m88k_store_arguments (regcache, nargs, args, sp);
+  gdb_assert (sp % 16 == 0);
+
+  /* Store return value address.  */
+  if (struct_return)
+    regcache_raw_write_unsigned (regcache, M88K_R12_REGNUM, struct_addr);
+
+  /* Store the stack pointer and return address in the appropriate
+     registers.  */
+  regcache_raw_write_unsigned (regcache, M88K_R31_REGNUM, sp);
+  regcache_raw_write_unsigned (regcache, M88K_R1_REGNUM, bp_addr);
+
+  /* Return the stack pointer.  */
+  return sp;
+}
+
+static struct frame_id
+m88k_unwind_dummy_id (struct gdbarch *arch, struct frame_info *next_frame)
+{
+  CORE_ADDR sp;
+
+  sp = frame_unwind_register_unsigned (next_frame, M88K_R31_REGNUM);
+  return frame_id_build (sp, frame_pc_unwind (next_frame));
+}
+
+
+/* Determine, for architecture GDBARCH, how a return value of TYPE
+   should be returned.  If it is supposed to be returned in registers,
+   and READBUF is non-zero, read the appropriate value from REGCACHE,
+   and copy it into READBUF.  If WRITEBUF is non-zero, write the value
+   from WRITEBUF into REGCACHE.  */
+
+static enum return_value_convention
+m88k_return_value (struct gdbarch *gdbarch, struct type *type,
+		   struct regcache *regcache, void *readbuf,
+		   const void *writebuf)
+{
+  int len = TYPE_LENGTH (type);
+  char buf[8];
+
+  if (!m88k_integral_or_pointer_p (type) && !m88k_floating_p (type))
+    return RETURN_VALUE_STRUCT_CONVENTION;
+
+  if (readbuf)
+    {
+      /* Read the contents of R2 and (if necessary) R3.  */
+      regcache_cooked_read (regcache, M88K_R2_REGNUM, buf);
+      if (len > 4)
+	{
+	  regcache_cooked_read (regcache, M88K_R3_REGNUM, buf + 4);
+	  gdb_assert (len == 8);
+	  memcpy (readbuf, buf, len);
+	}
+      else
+	{
+	  /* Just stripping off any unused bytes should preserve the
+             signed-ness just fine.  */
+	  memcpy (readbuf, buf + 4 - len, len);
+	}
+    }
+
+  if (writebuf)
+    {
+      /* Read the contents to R2 and (if necessary) R3.  */
+      if (len > 4)
+	{
+	  gdb_assert (len == 8);
+	  memcpy (buf, writebuf, 8);
+	  regcache_cooked_write (regcache, M88K_R3_REGNUM, buf + 4);
+	}
+      else
+	{
+	  /* ??? Do we need to do any sign-extension here?  */
+	  memcpy (buf + 4 - len, writebuf, len);
+	}
+      regcache_cooked_write (regcache, M88K_R2_REGNUM, buf);
+    }
+
+  return RETURN_VALUE_REGISTER_CONVENTION;
+}
+
+/* Default frame unwinder.  */
+
+struct m88k_frame_cache
+{
+  /* Base address.  */
+  CORE_ADDR base;
+  CORE_ADDR pc;
+
+  int sp_offset;
+  int fp_offset;
+
+  /* Table of saved registers.  */
+  struct trad_frame_saved_reg *saved_regs;
+};
+
+/* Prologue analysis.  */
+
+/* Macros for extracting fields from instructions.  */
+
+#define BITMASK(pos, width) (((0x1 << (width)) - 1) << (pos))
+#define EXTRACT_FIELD(val, pos, width) ((val) >> (pos) & BITMASK (0, width))
+#define	SUBU_OFFSET(x)	((unsigned)(x & 0xFFFF))
+#define	ST_OFFSET(x)	((unsigned)((x) & 0xFFFF))
+#define	ST_SRC(x)	EXTRACT_FIELD ((x), 21, 5)
+#define	ADDU_OFFSET(x)	((unsigned)(x & 0xFFFF))
+
+/* Possible actions to be taken by the prologue analyzer for the
+   instructions it encounters.  */
+
+enum m88k_prologue_insn_action
+{
+  M88K_PIA_SKIP,		/* Ignore.  */
+  M88K_PIA_NOTE_ST,		/* Note register store.  */
+  M88K_PIA_NOTE_STD,		/* Note register pair store.  */
+  M88K_PIA_NOTE_SP_ADJUSTMENT,	/* Note stack pointer adjustment.  */
+  M88K_PIA_NOTE_FP_ASSIGNMENT,	/* Note frame pointer assignment.  */
+  M88K_PIA_NOTE_BRANCH,		/* Note branch.  */
+  M88K_PIA_NOTE_PROLOGUE_END	/* Note end of prologue.  */
+};
+
+/* Table of instructions that may comprise a function prologue.  */
+
+struct m88k_prologue_insn
+{
+  unsigned long insn;
+  unsigned long mask;
+  enum m88k_prologue_insn_action action;
+};
+
+struct m88k_prologue_insn m88k_prologue_insn_table[] =
+{
+  /* Various register move instructions.  */
+  { 0x58000000, 0xf800ffff, M88K_PIA_SKIP },     /* or/or.u with immed of 0 */
+  { 0xf4005800, 0xfc1fffe0, M88K_PIA_SKIP },     /* or rd,r0,rs */
+  { 0xf4005800, 0xfc00ffff, M88K_PIA_SKIP },     /* or rd,rs,r0 */
+
+  /* Various other instructions.  */
+  { 0x58000000, 0xf8000000, M88K_PIA_SKIP },     /* or/or.u */
+
+  /* Stack pointer setup: "subu sp,sp,n" where n is a multiple of 8.  */
+  { 0x67ff0000, 0xffff0007, M88K_PIA_NOTE_SP_ADJUSTMENT },
+
+  /* Frame pointer assignment: "addu r30,r31,n".  */
+  { 0x63df0000, 0xffff0000, M88K_PIA_NOTE_FP_ASSIGNMENT },
+
+  /* Store to stack instructions; either "st rx,sp,n" or "st.d rx,sp,n".  */
+  { 0x241f0000, 0xfc1f0000, M88K_PIA_NOTE_ST },  /* st rx,sp,n */
+  { 0x201f0000, 0xfc1f0000, M88K_PIA_NOTE_STD }, /* st.d rs,sp,n */
+
+  /* Instructions needed for setting up r25 for pic code.  */
+  { 0x5f200000, 0xffff0000, M88K_PIA_SKIP },     /* or.u r25,r0,offset_high */
+  { 0xcc000002, 0xffffffff, M88K_PIA_SKIP },     /* bsr.n Lab */
+  { 0x5b390000, 0xffff0000, M88K_PIA_SKIP },     /* or r25,r25,offset_low */
+  { 0xf7396001, 0xffffffff, M88K_PIA_SKIP },     /* Lab: addu r25,r25,r1 */
+
+  /* Various branch or jump instructions which have a delay slot --
+     these do not form part of the prologue, but the instruction in
+     the delay slot might be a store instruction which should be
+     noted.  */
+  { 0xc4000000, 0xe4000000, M88K_PIA_NOTE_BRANCH },
+                                      /* br.n, bsr.n, bb0.n, or bb1.n */
+  { 0xec000000, 0xfc000000, M88K_PIA_NOTE_BRANCH }, /* bcnd.n */
+  { 0xf400c400, 0xfffff7e0, M88K_PIA_NOTE_BRANCH }, /* jmp.n or jsr.n */
+
+  /* Catch all.  Ends prologue analysis.  */
+  { 0x00000000, 0x00000000, M88K_PIA_NOTE_PROLOGUE_END }
+};
+
+/* Do a full analysis of the function prologue at PC and update CACHE
+   accordingly.  Bail out early if LIMIT is reached.  Return the
+   address where the analysis stopped.  If LIMIT points beyond the
+   function prologue, the return address should be the end of the
+   prologue.  */
+
+static CORE_ADDR
+m88k_analyze_prologue (CORE_ADDR pc, CORE_ADDR limit,
+		       struct m88k_frame_cache *cache)
+{
+  CORE_ADDR end = limit;
+
+  /* Provide a dummy cache if necessary.  */
+  if (cache == NULL)
+    {
+      size_t sizeof_saved_regs =
+	(M88K_R31_REGNUM + 1) * sizeof (struct trad_frame_saved_reg);
+
+      cache = alloca (sizeof (struct m88k_frame_cache));
+      cache->saved_regs = alloca (sizeof_saved_regs);
+
+      /* We only initialize the members we care about.  */
+      cache->saved_regs[M88K_R1_REGNUM].addr = -1;
+      cache->fp_offset = -1;
+    }
+
+  while (pc < limit)
+    {
+      struct m88k_prologue_insn *pi = m88k_prologue_insn_table;
+      unsigned long insn = m88k_fetch_instruction (pc);
+
+      while ((insn & pi->mask) != pi->insn)
+	pi++;
+
+      switch (pi->action)
+	{
+	case M88K_PIA_SKIP:
+	  /* If we have a frame pointer, and R1 has been saved,
+             consider this instruction as not being part of the
+             prologue.  */
+	  if (cache->fp_offset != -1
+	      && cache->saved_regs[M88K_R1_REGNUM].addr != -1)
+	    return min (pc, end);
+	  break;
+
+	case M88K_PIA_NOTE_ST:
+	case M88K_PIA_NOTE_STD:
+	  /* If no frame has been allocated, the stores aren't part of
+             the prologue.  */
+	  if (cache->sp_offset == 0)
+	    return min (pc, end);
+
+	  /* Record location of saved registers.  */
+	  {
+	    int regnum = ST_SRC (insn) + M88K_R0_REGNUM;
+	    ULONGEST offset = ST_OFFSET (insn);
+
+	    cache->saved_regs[regnum].addr = offset;
+	    if (pi->action == M88K_PIA_NOTE_STD && regnum < M88K_R31_REGNUM)
+	      cache->saved_regs[regnum + 1].addr = offset + 4;
+	  }
+	  break;
+
+	case M88K_PIA_NOTE_SP_ADJUSTMENT:
+	  /* A second stack pointer adjustment isn't part of the
+             prologue.  */
+	  if (cache->sp_offset != 0)
+	    return min (pc, end);
+
+	  /* Store stack pointer adjustment.  */
+	  cache->sp_offset = -SUBU_OFFSET (insn);
+	  break;
+
+	case M88K_PIA_NOTE_FP_ASSIGNMENT:
+	  /* A second frame pointer assignment isn't part of the
+             prologue.  */
+	  if (cache->fp_offset != -1)
+	    return min (pc, end);
+
+	  /* Record frame pointer assignment.  */
+	  cache->fp_offset = ADDU_OFFSET (insn);
+	  break;
+
+	case M88K_PIA_NOTE_BRANCH:
+	  /* The branch instruction isn't part of the prologue, but
+             the instruction in the delay slot might be.  Limit the
+             prologue analysis to the delay slot and record the branch
+             instruction as the end of the prologue.  */
+	  limit = pc + M88K_INSN_SIZE;
+	  end = pc;
+	  break;
+
+	case M88K_PIA_NOTE_PROLOGUE_END:
+	  return min (pc, end);
+	}
+
+      pc += M88K_INSN_SIZE;
+    }
+
+  return end;
+}
+
+/* An upper limit to the size of the prologue.  */
+const int m88k_max_prologue_size = 128 * M88K_INSN_SIZE;
+
+/* Return the address of first real instruction of the function
+   starting at PC.  */
+
+static CORE_ADDR
+m88k_skip_prologue (CORE_ADDR pc)
+{
+  struct symtab_and_line sal;
+  CORE_ADDR func_start, func_end;
+
+  /* This is the preferred method, find the end of the prologue by
+     using the debugging information.  */
+  if (find_pc_partial_function (pc, NULL, &func_start, &func_end))
+    {
+      sal = find_pc_line (func_start, 0);
+
+      if (sal.end < func_end && pc <= sal.end)
+	return sal.end;
+    }
+
+  return m88k_analyze_prologue (pc, pc + m88k_max_prologue_size, NULL);
+}
+
+struct m88k_frame_cache *
+m88k_frame_cache (struct frame_info *next_frame, void **this_cache)
+{
+  struct m88k_frame_cache *cache;
+  CORE_ADDR frame_sp;
+
+  if (*this_cache)
+    return *this_cache;
+
+  cache = FRAME_OBSTACK_ZALLOC (struct m88k_frame_cache);
+  cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);
+  cache->fp_offset = -1;
+
+  cache->pc = frame_func_unwind (next_frame);
+  if (cache->pc != 0)
+    {
+      CORE_ADDR addr_in_block = frame_unwind_address_in_block (next_frame);
+      m88k_analyze_prologue (cache->pc, addr_in_block, cache);
+    }
+
+  /* Calculate the stack pointer used in the prologue.  */
+  if (cache->fp_offset != -1)
+    {
+      CORE_ADDR fp;
+
+      fp = frame_unwind_register_unsigned (next_frame, M88K_R30_REGNUM);
+      frame_sp = fp - cache->fp_offset;
+    }
+  else
+    {
+      /* If we know where the return address is saved, we can take a
+         solid guess at what the frame pointer should be.  */
+      if (cache->saved_regs[M88K_R1_REGNUM].addr != -1)
+	cache->fp_offset = cache->saved_regs[M88K_R1_REGNUM].addr - 4;
+      frame_sp = frame_unwind_register_unsigned (next_frame, M88K_R31_REGNUM);
+    }
+
+  /* Now that we know the stack pointer, adjust the location of the
+     saved registers.  */
+  {
+    int regnum;
+
+    for (regnum = M88K_R0_REGNUM; regnum < M88K_R31_REGNUM; regnum ++)
+      if (cache->saved_regs[regnum].addr != -1)
+	cache->saved_regs[regnum].addr += frame_sp;
+  }
+
+  /* Calculate the frame's base.  */
+  cache->base = frame_sp - cache->sp_offset;
+  trad_frame_set_value (cache->saved_regs, M88K_R31_REGNUM, cache->base);
+
+  /* Identify SXIP with the return address in R1.  */
+  cache->saved_regs[M88K_SXIP_REGNUM] = cache->saved_regs[M88K_R1_REGNUM];
+
+  *this_cache = cache;
+  return cache;
+}
+
+static void
+m88k_frame_this_id (struct frame_info *next_frame, void **this_cache,
+		    struct frame_id *this_id)
+{
+  struct m88k_frame_cache *cache = m88k_frame_cache (next_frame, this_cache);
+
+  /* This marks the outermost frame.  */
+  if (cache->base == 0)
+    return;
+
+  (*this_id) = frame_id_build (cache->base, cache->pc);
+}
+
+static void
+m88k_frame_prev_register (struct frame_info *next_frame, void **this_cache,
+			  int regnum, int *optimizedp,
+			  enum lval_type *lvalp, CORE_ADDR *addrp,
+			  int *realnump, void *valuep)
+{
+  struct m88k_frame_cache *cache = m88k_frame_cache (next_frame, this_cache);
+
+  if (regnum == M88K_SNIP_REGNUM || regnum == M88K_SFIP_REGNUM)
+    {
+      if (valuep)
+	{
+	  CORE_ADDR pc;
+
+	  trad_frame_prev_register (next_frame, cache->saved_regs,
+				    M88K_SXIP_REGNUM, optimizedp,
+				    lvalp, addrp, realnump, valuep);
+
+	  pc = extract_unsigned_integer (valuep, 4);
+	  if (regnum == M88K_SNIP_REGNUM)
+	    pc += 4;
+	  else if (regnum == M88K_SFIP_REGNUM)
+	    pc += 8;
+	  store_unsigned_integer (valuep, 4, pc);
+	}
+
+      /* It's a computed value.  */
+      *optimizedp = 0;
+      *lvalp = not_lval;
+      *addrp = 0;
+      *realnump = -1;
+      return;
+    }
+
+  trad_frame_prev_register (next_frame, cache->saved_regs, regnum,
+			    optimizedp, lvalp, addrp, realnump, valuep);
+}
+
+static const struct frame_unwind m88k_frame_unwind =
+{
+  NORMAL_FRAME,
+  m88k_frame_this_id,
+  m88k_frame_prev_register
+};
+
+static const struct frame_unwind *
+m88k_frame_sniffer (struct frame_info *next_frame)
+{
+  return &m88k_frame_unwind;
+}
+
+
+static CORE_ADDR
+m88k_frame_base_address (struct frame_info *next_frame, void **this_cache)
+{
+  struct m88k_frame_cache *cache = m88k_frame_cache (next_frame, this_cache);
+
+  if (cache->fp_offset != -1)
+    return cache->base + cache->sp_offset + cache->fp_offset;
+
+  return 0;
+}
+
+static const struct frame_base m88k_frame_base =
+{
+  &m88k_frame_unwind,
+  m88k_frame_base_address,
+  m88k_frame_base_address,
+  m88k_frame_base_address
+};
+
+
+/* Core file support.  */
+
+/* Supply register REGNUM from the buffer specified by GREGS and LEN
+   in the general-purpose register set REGSET to register cache
+   REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
+
+static void
+m88k_supply_gregset (const struct regset *regset,
+		     struct regcache *regcache,
+		     int regnum, const void *gregs, size_t len)
+{
+  const char *regs = gregs;
+  int i;
+
+  for (i = 0; i < M88K_NUM_REGS; i++)
+    {
+      if (regnum == i || regnum == -1)
+	regcache_raw_supply (regcache, i, regs + i * 4);
+    }
+}
+
+/* Motorola 88000 register set.  */
+
+static struct regset m88k_gregset =
+{
+  NULL,
+  m88k_supply_gregset
+};
+
+/* Return the appropriate register set for the core section identified
+   by SECT_NAME and SECT_SIZE.  */
+
+static const struct regset *
+m88k_regset_from_core_section (struct gdbarch *gdbarch,
+			       const char *sect_name, size_t sect_size)
+{
+  if (strcmp (sect_name, ".reg") == 0 && sect_size >= M88K_NUM_REGS * 4)
+    return &m88k_gregset;
+
+  return NULL;
+}
+
+
+static struct gdbarch *
+m88k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
+{
+  struct gdbarch *gdbarch;
+
+  /* If there is already a candidate, use it.  */
+  arches = gdbarch_list_lookup_by_info (arches, &info);
+  if (arches != NULL)
+    return arches->gdbarch;
+
+  /* Allocate space for the new architecture.  */
+  gdbarch = gdbarch_alloc (&info, NULL);
+
+  /* There is no real `long double'.  */
+  set_gdbarch_long_double_bit (gdbarch, 64);
+  set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
+
+  set_gdbarch_num_regs (gdbarch, M88K_NUM_REGS);
+  set_gdbarch_register_name (gdbarch, m88k_register_name);
+  set_gdbarch_register_type (gdbarch, m88k_register_type);
+
+  /* Register numbers of various important registers.  */
+  set_gdbarch_sp_regnum (gdbarch, M88K_R31_REGNUM);
+  set_gdbarch_pc_regnum (gdbarch, M88K_SXIP_REGNUM);
+
+  /* Core file support.  */
+  set_gdbarch_regset_from_core_section
+    (gdbarch, m88k_regset_from_core_section);
+
+  set_gdbarch_print_insn (gdbarch, print_insn_m88k);
+
+  set_gdbarch_skip_prologue (gdbarch, m88k_skip_prologue);
+
+  /* Stack grows downward.  */
+  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
+
+  /* Call dummy code.  */
+  set_gdbarch_push_dummy_call (gdbarch, m88k_push_dummy_call);
+  set_gdbarch_unwind_dummy_id (gdbarch, m88k_unwind_dummy_id);
+
+  /* Return value info */
+  set_gdbarch_return_value (gdbarch, m88k_return_value);
+
+  set_gdbarch_addr_bits_remove (gdbarch, m88k_addr_bits_remove);
+  set_gdbarch_breakpoint_from_pc (gdbarch, m88k_breakpoint_from_pc);
+  set_gdbarch_unwind_pc (gdbarch, m88k_unwind_pc);
+  set_gdbarch_write_pc (gdbarch, m88k_write_pc);
+
+  frame_base_set_default (gdbarch, &m88k_frame_base);
+  frame_unwind_append_sniffer (gdbarch, m88k_frame_sniffer);
+
+  return gdbarch;
+}
+
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+void _initialize_m88k_tdep (void);
+
+void
+_initialize_m88k_tdep (void)
+{
+  gdbarch_register (bfd_arch_m88k, m88k_gdbarch_init, NULL);
+}