Add PDP-11 support

1 files changed, 323 insertions, 0 deletions

diff --git a/opcodes/pdp11-dis.c b/opcodes/pdp11-dis.c
new file mode 100644
index 0000000..e13c7aa
--- /dev/null
+++ b/opcodes/pdp11-dis.c
@@ -0,0 +1,323 @@
+/* Print DEC PDP-11 instructions.
+   Copyright 2001 Free Software Foundation, Inc.
+
+This file 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 "dis-asm.h"
+#include "opcode/pdp11.h"
+
+#define AFTER_INSTRUCTION	"\t"
+#define OPERAND_SEPARATOR	", "
+
+#define JUMP	0x1000	/* flag that this operand is used in a jump */
+
+#define FPRINTF	(*info->fprintf_func)
+#define F	info->stream
+
+/* sign-extend a 16-bit number in an int */
+#define SIGN_BITS	(8 * sizeof (int) - 16)
+#define sign_extend(x) (((x) << SIGN_BITS) >> SIGN_BITS)
+
+static int read_word PARAMS ((bfd_vma memaddr, int *word,
+			      disassemble_info *info));
+static void print_signed_octal PARAMS ((int n, disassemble_info *info));
+static void print_reg PARAMS ((int reg, disassemble_info *info));
+static void print_freg PARAMS ((int freg, disassemble_info *info));
+static int print_operand PARAMS ((bfd_vma *memaddr, int code,
+				  disassemble_info *info));
+int print_insn_pdp11 PARAMS ((bfd_vma memaddr, disassemble_info *info));
+
+static int
+read_word (memaddr, word, info)
+     bfd_vma memaddr;
+     int *word;
+     disassemble_info *info;
+{
+  int status;
+  bfd_byte x[2];
+
+  status = (*info->read_memory_func) (memaddr, x, 2, info);
+  if (status != 0)
+    return -1;
+
+  *word = x[1] << 8 | x[0];
+  return 0;
+}
+
+static void
+print_signed_octal (n, info)
+     int n;
+     disassemble_info *info;
+{
+  if (n < 0)
+    FPRINTF (F, "-%o", -n);
+  else
+    FPRINTF (F, "%o", n);
+}
+
+static void
+print_reg (reg, info)
+     int reg;
+     disassemble_info *info;
+{
+  /* mask off the addressing mode, if any */
+  reg &= 7;
+
+  switch (reg)
+    {
+    case 0: case 1: case 2: case 3: case 4: case 5:
+		FPRINTF (F, "r%d", reg); break;
+    case 6:	FPRINTF (F, "sp"); break;
+    case 7:	FPRINTF (F, "pc"); break;
+    default:	/* error */
+    }
+}
+
+static void
+print_freg (freg, info)
+     int freg;
+     disassemble_info *info;
+{
+  FPRINTF (F, "fr%d", freg);
+}
+
+static int
+print_operand (memaddr, code, info)
+     bfd_vma *memaddr;
+     int code;
+     disassemble_info *info;
+{
+  int mode = (code >> 3) & 7;
+  int reg = code & 7;
+  int disp;
+
+  switch (mode)
+    {
+    case 0:
+      print_reg (reg, info);
+      break;
+    case 1:
+      FPRINTF (F, "(");
+      print_reg (reg, info);
+      FPRINTF (F, ")");
+      break;
+    case 2:
+      if (reg == 7)
+	{
+	  int data;
+	  if (read_word (*memaddr, &data, info) < 0)
+	    return -1;
+	  FPRINTF (F, "$");
+	  print_signed_octal (sign_extend (data), info);
+	  *memaddr += 2;
+	}
+      else
+	{
+	  FPRINTF (F, "(");
+	  print_reg (reg, info);
+	  FPRINTF (F, ")+");
+	}
+	break;
+    case 3:
+      if (reg == 7)
+	{
+	  int address;
+	  if (read_word (*memaddr, &address, info) < 0)
+	    return -1;
+	  FPRINTF (F, "*$%o", address);
+	  *memaddr += 2;
+	}
+      else
+	{
+	  FPRINTF (F, "*(");
+	  print_reg (reg, info);
+	  FPRINTF (F, ")+");
+	}
+	break;
+    case 4:
+      FPRINTF (F, "-(");
+      print_reg (reg, info);
+      FPRINTF (F, ")");
+      break;
+    case 5:
+      FPRINTF (F, "*-(");
+      print_reg (reg, info);
+      FPRINTF (F, ")");
+      break;
+    case 6:
+    case 7:
+      if (read_word (*memaddr, &disp, info) < 0)
+	return -1;
+      *memaddr += 2;
+      if (reg == 7)
+	{
+	  bfd_vma address = *memaddr + sign_extend (disp);
+	  if (!(code & JUMP))
+	    FPRINTF (F, "*$");
+	  (*info->print_address_func) (address, info);
+	}
+      else
+	{
+	  if (mode == 7)
+	    FPRINTF (F, "*");
+	  print_signed_octal (sign_extend (disp), info);
+	  FPRINTF (F, "(");
+	  print_reg (reg, info);
+	  FPRINTF (F, ")");
+	}
+      break;
+    }
+
+  return 0;
+}
+
+/* Print the PDP-11 instruction at address MEMADDR in debugged memory,
+   on INFO->STREAM.  Returns length of the instruction, in bytes.  */
+
+int
+print_insn_pdp11 (memaddr, info)
+     bfd_vma memaddr;
+     disassemble_info *info;
+{
+  bfd_vma start_memaddr = memaddr;
+  int opcode;
+  int src, dst;
+  int i;
+
+  info->bytes_per_line = 6;
+  info->bytes_per_chunk = 2;
+  info->display_endian = BFD_ENDIAN_LITTLE;
+
+  if (read_word (memaddr, &opcode, info) != 0)
+    return -1;
+  memaddr += 2;
+
+  src = (opcode >> 6) & 0x3f;
+  dst = opcode & 0x3f;
+
+  for (i = 0; i < pdp11_num_opcodes; i++)
+    {
+#define OP pdp11_opcodes[i]
+      if ((opcode & OP.mask) == OP.opcode)
+	switch (OP.type)
+	  {
+	  case PDP11_OPCODE_NO_OPS:
+	    FPRINTF (F, OP.name);
+	    break;
+	  case PDP11_OPCODE_REG:
+	    FPRINTF (F, OP.name);
+	    FPRINTF (F, AFTER_INSTRUCTION);
+	    print_reg (dst, info);
+	    break;
+	  case PDP11_OPCODE_OP:
+	    FPRINTF (F, OP.name);
+	    FPRINTF (F, AFTER_INSTRUCTION);
+	    if (strcmp (OP.name, "jmp") == 0)
+	      dst |= JUMP;
+	    if (print_operand (&memaddr, dst, info) < 0)
+	      return -1;
+	    break;
+	  case PDP11_OPCODE_REG_OP:
+	    FPRINTF (F, OP.name);
+	    FPRINTF (F, AFTER_INSTRUCTION);
+	    print_reg (src, info);
+	    FPRINTF (F, OPERAND_SEPARATOR);
+	    if (strcmp (OP.name, "jsr") == 0)
+	      dst |= JUMP;
+	    if (print_operand (&memaddr, dst, info) < 0)
+	      return -1;
+	    break;
+	  case PDP11_OPCODE_REG_OP_REV:
+	    FPRINTF (F, OP.name);
+	    FPRINTF (F, AFTER_INSTRUCTION);
+	    if (print_operand (&memaddr, dst, info) < 0)
+	      return -1;
+	    FPRINTF (F, OPERAND_SEPARATOR);
+	    print_reg (src, info);
+	    break;
+	  case PDP11_OPCODE_AC_OP:
+	    {
+	      int ac = (opcode & 0xe0) >> 6;
+	      FPRINTF (F, OP.name);
+	      FPRINTF (F, AFTER_INSTRUCTION);
+	      print_freg (ac, info);
+	      FPRINTF (F, OPERAND_SEPARATOR);
+	      if (print_operand (&memaddr, dst, info) < 0)
+		return -1;
+	      break;
+	    }
+	  case PDP11_OPCODE_OP_OP:
+	    FPRINTF (F, OP.name);
+	    FPRINTF (F, AFTER_INSTRUCTION);
+	    if (print_operand (&memaddr, src, info) < 0)
+	      return -1;
+	    FPRINTF (F, OPERAND_SEPARATOR);
+	    if (print_operand (&memaddr, dst, info) < 0)
+	      return -1;
+	    break;
+	  case PDP11_OPCODE_DISPL:
+	    {
+	      int displ = (opcode & 0xff) << 8;
+	      bfd_vma address = memaddr + (sign_extend (displ) >> 7);
+	      FPRINTF (F, OP.name);
+	      FPRINTF (F, AFTER_INSTRUCTION);
+	      (*info->print_address_func) (address, info);
+	      break;
+	    }
+	  case PDP11_OPCODE_REG_DISPL:
+	    {
+	      int displ = (opcode & 0x3f) << 10;
+	      bfd_vma address = memaddr + (sign_extend (displ) >> 9);
+	      FPRINTF (F, OP.name);
+	      FPRINTF (F, AFTER_INSTRUCTION);
+	      print_reg (src, info);
+	      FPRINTF (F, OPERAND_SEPARATOR);
+	      (*info->print_address_func) (address, info);
+	      break;
+	    }
+	  case PDP11_OPCODE_IMM8:
+	    {
+	      int code = opcode & 0xff;
+	      FPRINTF (F, OP.name);
+	      FPRINTF (F, AFTER_INSTRUCTION);
+	      FPRINTF (F, "%o", code);
+	      break;
+	    }
+	  case PDP11_OPCODE_IMM6:
+	    {
+	      int code = opcode & 0x3f;
+	      FPRINTF (F, OP.name);
+	      FPRINTF (F, AFTER_INSTRUCTION);
+	      FPRINTF (F, "%o", code);
+	      break;
+	    }
+	  case PDP11_OPCODE_IMM3:
+	    {
+	      int code = opcode & 7;
+	      FPRINTF (F, OP.name);
+	      FPRINTF (F, AFTER_INSTRUCTION);
+	      FPRINTF (F, "%o", code);
+	      break;
+	    }
+	  default:
+	    /* TODO: is this a proper way of signalling an error? */
+	    FPRINTF (F, "<internal error: unrecognized instruction type>");
+	    return -1;
+	  }
+#undef OP
+    }
+
+  return memaddr - start_memaddr;
+}