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      1 /* Disassemble AVR instructions.
      2    Copyright (C) 1999-2016 Free Software Foundation, Inc.
      3 
      4    Contributed by Denis Chertykov <denisc (at) overta.ru>
      5 
      6    This file is part of libopcodes.
      7 
      8    This library is free software; you can redistribute it and/or modify
      9    it under the terms of the GNU General Public License as published by
     10    the Free Software Foundation; either version 3, or (at your option)
     11    any later version.
     12 
     13    It is distributed in the hope that it will be useful, but WITHOUT
     14    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
     15    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
     16    License for more details.
     17 
     18    You should have received a copy of the GNU General Public License
     19    along with this program; if not, write to the Free Software
     20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
     21    MA 02110-1301, USA.  */
     22 
     23 #include "sysdep.h"
     24 #include <assert.h>
     25 #include "dis-asm.h"
     26 #include "opintl.h"
     27 #include "libiberty.h"
     28 
     29 struct avr_opcodes_s
     30 {
     31   char *name;
     32   char *constraints;
     33   char *opcode;
     34   int insn_size;		/* In words.  */
     35   int isa;
     36   unsigned int bin_opcode;
     37 };
     38 
     39 #define AVR_INSN(NAME, CONSTR, OPCODE, SIZE, ISA, BIN) \
     40 {#NAME, CONSTR, OPCODE, SIZE, ISA, BIN},
     41 
     42 const struct avr_opcodes_s avr_opcodes[] =
     43 {
     44   #include "opcode/avr.h"
     45   {NULL, NULL, NULL, 0, 0, 0}
     46 };
     47 
     48 static const char * comment_start = "0x";
     49 
     50 static int
     51 avr_operand (unsigned int insn, unsigned int insn2, unsigned int pc, int constraint,
     52              char *opcode_str, char *buf, char *comment, int regs, int *sym, bfd_vma *sym_addr)
     53 {
     54   int ok = 1;
     55   *sym = 0;
     56 
     57   switch (constraint)
     58     {
     59       /* Any register operand.  */
     60     case 'r':
     61       if (regs)
     62 	insn = (insn & 0xf) | ((insn & 0x0200) >> 5); /* Source register.  */
     63       else
     64 	insn = (insn & 0x01f0) >> 4; /* Destination register.  */
     65 
     66       sprintf (buf, "r%d", insn);
     67       break;
     68 
     69     case 'd':
     70       if (regs)
     71 	sprintf (buf, "r%d", 16 + (insn & 0xf));
     72       else
     73 	sprintf (buf, "r%d", 16 + ((insn & 0xf0) >> 4));
     74       break;
     75 
     76     case 'w':
     77       sprintf (buf, "r%d", 24 + ((insn & 0x30) >> 3));
     78       break;
     79 
     80     case 'a':
     81       if (regs)
     82 	sprintf (buf, "r%d", 16 + (insn & 7));
     83       else
     84 	sprintf (buf, "r%d", 16 + ((insn >> 4) & 7));
     85       break;
     86 
     87     case 'v':
     88       if (regs)
     89 	sprintf (buf, "r%d", (insn & 0xf) * 2);
     90       else
     91 	sprintf (buf, "r%d", ((insn & 0xf0) >> 3));
     92       break;
     93 
     94     case 'e':
     95       {
     96 	char *xyz;
     97 
     98 	switch (insn & 0x100f)
     99 	  {
    100 	    case 0x0000: xyz = "Z";  break;
    101 	    case 0x1001: xyz = "Z+"; break;
    102 	    case 0x1002: xyz = "-Z"; break;
    103 	    case 0x0008: xyz = "Y";  break;
    104 	    case 0x1009: xyz = "Y+"; break;
    105 	    case 0x100a: xyz = "-Y"; break;
    106 	    case 0x100c: xyz = "X";  break;
    107 	    case 0x100d: xyz = "X+"; break;
    108 	    case 0x100e: xyz = "-X"; break;
    109 	    default: xyz = "??"; ok = 0;
    110 	  }
    111 	strcpy (buf, xyz);
    112 
    113 	if (AVR_UNDEF_P (insn))
    114 	  sprintf (comment, _("undefined"));
    115       }
    116       break;
    117 
    118     case 'z':
    119       *buf++ = 'Z';
    120 
    121       /* Check for post-increment. */
    122       char *s;
    123       for (s = opcode_str; *s; ++s)
    124         {
    125           if (*s == '+')
    126             {
    127 	      if (insn & (1 << (15 - (s - opcode_str))))
    128 		*buf++ = '+';
    129               break;
    130             }
    131         }
    132 
    133       *buf = '\0';
    134       if (AVR_UNDEF_P (insn))
    135 	sprintf (comment, _("undefined"));
    136       break;
    137 
    138     case 'b':
    139       {
    140 	unsigned int x;
    141 
    142 	x = (insn & 7);
    143 	x |= (insn >> 7) & (3 << 3);
    144 	x |= (insn >> 8) & (1 << 5);
    145 
    146 	if (insn & 0x8)
    147 	  *buf++ = 'Y';
    148 	else
    149 	  *buf++ = 'Z';
    150 	sprintf (buf, "+%d", x);
    151 	sprintf (comment, "0x%02x", x);
    152       }
    153       break;
    154 
    155     case 'h':
    156       *sym = 1;
    157       *sym_addr = ((((insn & 1) | ((insn & 0x1f0) >> 3)) << 16) | insn2) * 2;
    158       /* See PR binutils/2454.  Ideally we would like to display the hex
    159 	 value of the address only once, but this would mean recoding
    160 	 objdump_print_address() which would affect many targets.  */
    161       sprintf (buf, "%#lx", (unsigned long) *sym_addr);
    162       strcpy (comment, comment_start);
    163       break;
    164 
    165     case 'L':
    166       {
    167 	int rel_addr = (((insn & 0xfff) ^ 0x800) - 0x800) * 2;
    168 	sprintf (buf, ".%+-8d", rel_addr);
    169         *sym = 1;
    170         *sym_addr = pc + 2 + rel_addr;
    171 	strcpy (comment, comment_start);
    172       }
    173       break;
    174 
    175     case 'l':
    176       {
    177 	int rel_addr = ((((insn >> 3) & 0x7f) ^ 0x40) - 0x40) * 2;
    178 
    179 	sprintf (buf, ".%+-8d", rel_addr);
    180         *sym = 1;
    181         *sym_addr = pc + 2 + rel_addr;
    182 	strcpy (comment, comment_start);
    183       }
    184       break;
    185 
    186     case 'i':
    187       {
    188         unsigned int val = insn2 | 0x800000;
    189         *sym = 1;
    190         *sym_addr = val;
    191         sprintf (buf, "0x%04X", insn2);
    192         strcpy (comment, comment_start);
    193       }
    194       break;
    195 
    196     case 'j':
    197       {
    198         unsigned int val = ((insn & 0xf) | ((insn & 0x600) >> 5)
    199                                          | ((insn & 0x100) >> 2));
    200         *sym = 1;
    201         *sym_addr = val | 0x800000;
    202         sprintf (buf, "0x%02x", val);
    203         strcpy (comment, comment_start);
    204       }
    205       break;
    206 
    207     case 'M':
    208       sprintf (buf, "0x%02X", ((insn & 0xf00) >> 4) | (insn & 0xf));
    209       sprintf (comment, "%d", ((insn & 0xf00) >> 4) | (insn & 0xf));
    210       break;
    211 
    212     case 'n':
    213       sprintf (buf, "??");
    214       fprintf (stderr, _("Internal disassembler error"));
    215       ok = 0;
    216       break;
    217 
    218     case 'K':
    219       {
    220 	unsigned int x;
    221 
    222 	x = (insn & 0xf) | ((insn >> 2) & 0x30);
    223 	sprintf (buf, "0x%02x", x);
    224 	sprintf (comment, "%d", x);
    225       }
    226       break;
    227 
    228     case 's':
    229       sprintf (buf, "%d", insn & 7);
    230       break;
    231 
    232     case 'S':
    233       sprintf (buf, "%d", (insn >> 4) & 7);
    234       break;
    235 
    236     case 'P':
    237       {
    238 	unsigned int x;
    239 
    240 	x = (insn & 0xf);
    241 	x |= (insn >> 5) & 0x30;
    242 	sprintf (buf, "0x%02x", x);
    243 	sprintf (comment, "%d", x);
    244       }
    245       break;
    246 
    247     case 'p':
    248       {
    249 	unsigned int x;
    250 
    251 	x = (insn >> 3) & 0x1f;
    252 	sprintf (buf, "0x%02x", x);
    253 	sprintf (comment, "%d", x);
    254       }
    255       break;
    256 
    257     case 'E':
    258       sprintf (buf, "%d", (insn >> 4) & 15);
    259       break;
    260 
    261     case '?':
    262       *buf = '\0';
    263       break;
    264 
    265     default:
    266       sprintf (buf, "??");
    267       fprintf (stderr, _("unknown constraint `%c'"), constraint);
    268       ok = 0;
    269     }
    270 
    271     return ok;
    272 }
    273 
    274 static unsigned short
    275 avrdis_opcode (bfd_vma addr, disassemble_info *info)
    276 {
    277   bfd_byte buffer[2];
    278   int status;
    279 
    280   status = info->read_memory_func (addr, buffer, 2, info);
    281 
    282   if (status == 0)
    283     return bfd_getl16 (buffer);
    284 
    285   info->memory_error_func (status, addr, info);
    286   return -1;
    287 }
    288 
    289 
    290 int
    291 print_insn_avr (bfd_vma addr, disassemble_info *info)
    292 {
    293   unsigned int insn, insn2;
    294   const struct avr_opcodes_s *opcode;
    295   static unsigned int *maskptr;
    296   void *stream = info->stream;
    297   fprintf_ftype prin = info->fprintf_func;
    298   static unsigned int *avr_bin_masks;
    299   static int initialized;
    300   int cmd_len = 2;
    301   int ok = 0;
    302   char op1[20], op2[20], comment1[40], comment2[40];
    303   int sym_op1 = 0, sym_op2 = 0;
    304   bfd_vma sym_addr1, sym_addr2;
    305 
    306 
    307   if (!initialized)
    308     {
    309       unsigned int nopcodes;
    310 
    311       /* PR 4045: Try to avoid duplicating the 0x prefix that
    312 	 objdump_print_addr() will put on addresses when there
    313 	 is no symbol table available.  */
    314       if (info->symtab_size == 0)
    315 	comment_start = " ";
    316 
    317       nopcodes = sizeof (avr_opcodes) / sizeof (struct avr_opcodes_s);
    318 
    319       avr_bin_masks = xmalloc (nopcodes * sizeof (unsigned int));
    320 
    321       for (opcode = avr_opcodes, maskptr = avr_bin_masks;
    322 	   opcode->name;
    323 	   opcode++, maskptr++)
    324 	{
    325 	  char * s;
    326 	  unsigned int bin = 0;
    327 	  unsigned int mask = 0;
    328 
    329 	  for (s = opcode->opcode; *s; ++s)
    330 	    {
    331 	      bin <<= 1;
    332 	      mask <<= 1;
    333 	      bin |= (*s == '1');
    334 	      mask |= (*s == '1' || *s == '0');
    335 	    }
    336 	  assert (s - opcode->opcode == 16);
    337 	  assert (opcode->bin_opcode == bin);
    338 	  *maskptr = mask;
    339 	}
    340 
    341       initialized = 1;
    342     }
    343 
    344   insn = avrdis_opcode (addr, info);
    345 
    346   for (opcode = avr_opcodes, maskptr = avr_bin_masks;
    347        opcode->name;
    348        opcode++, maskptr++)
    349     {
    350       if ((opcode->isa == AVR_ISA_TINY) && (info->mach != bfd_mach_avrtiny))
    351         continue;
    352       if ((insn & *maskptr) == opcode->bin_opcode)
    353         break;
    354     }
    355 
    356   /* Special case: disassemble `ldd r,b+0' as `ld r,b', and
    357      `std b+0,r' as `st b,r' (next entry in the table).  */
    358 
    359   if (AVR_DISP0_P (insn))
    360     opcode++;
    361 
    362   op1[0] = 0;
    363   op2[0] = 0;
    364   comment1[0] = 0;
    365   comment2[0] = 0;
    366 
    367   if (opcode->name)
    368     {
    369       char *constraints = opcode->constraints;
    370       char *opcode_str = opcode->opcode;
    371 
    372       insn2 = 0;
    373       ok = 1;
    374 
    375       if (opcode->insn_size > 1)
    376 	{
    377 	  insn2 = avrdis_opcode (addr + 2, info);
    378 	  cmd_len = 4;
    379 	}
    380 
    381       if (*constraints && *constraints != '?')
    382 	{
    383 	  int regs = REGISTER_P (*constraints);
    384 
    385 	  ok = avr_operand (insn, insn2, addr, *constraints, opcode_str, op1, comment1, 0, &sym_op1, &sym_addr1);
    386 
    387 	  if (ok && *(++constraints) == ',')
    388 	    ok = avr_operand (insn, insn2, addr, *(++constraints), opcode_str, op2,
    389 			      *comment1 ? comment2 : comment1, regs, &sym_op2, &sym_addr2);
    390 	}
    391     }
    392 
    393   if (!ok)
    394     {
    395       /* Unknown opcode, or invalid combination of operands.  */
    396       sprintf (op1, "0x%04x", insn);
    397       op2[0] = 0;
    398       sprintf (comment1, "????");
    399       comment2[0] = 0;
    400     }
    401 
    402   (*prin) (stream, "%s", ok ? opcode->name : ".word");
    403 
    404   if (*op1)
    405       (*prin) (stream, "\t%s", op1);
    406 
    407   if (*op2)
    408     (*prin) (stream, ", %s", op2);
    409 
    410   if (*comment1)
    411     (*prin) (stream, "\t; %s", comment1);
    412 
    413   if (sym_op1)
    414     info->print_address_func (sym_addr1, info);
    415 
    416   if (*comment2)
    417     (*prin) (stream, " %s", comment2);
    418 
    419   if (sym_op2)
    420     info->print_address_func (sym_addr2, info);
    421 
    422   return cmd_len;
    423 }
    424