1 /* Print VAX instructions. 2 Copyright 1995, 1998, 2000, 2001, 2002 Free Software Foundation, Inc. 3 Contributed by Pauline Middelink <middelin@polyware.iaf.nl> 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 2 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program; if not, write to the Free Software 17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 18 19 #include "sysdep.h" 20 #include "opcode/vax.h" 21 #include "dis-asm.h" 22 23 /* Local function prototypes */ 24 static int fetch_data PARAMS ((struct disassemble_info *, bfd_byte *)); 25 static int print_insn_arg 26 PARAMS ((const char *, unsigned char *, bfd_vma, disassemble_info *)); 27 static int print_insn_mode 28 PARAMS ((const char *, int, unsigned char *, bfd_vma, disassemble_info *)); 29 30 31 static char *reg_names[] = 32 { 33 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", 34 "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc" 35 }; 36 37 /* Sign-extend an (unsigned char). */ 38 #if __STDC__ == 1 39 #define COERCE_SIGNED_CHAR(ch) ((signed char)(ch)) 40 #else 41 #define COERCE_SIGNED_CHAR(ch) ((int)(((ch) ^ 0x80) & 0xFF) - 128) 42 #endif 43 44 /* Get a 1 byte signed integer. */ 45 #define NEXTBYTE(p) \ 46 (p += 1, FETCH_DATA (info, p), \ 47 COERCE_SIGNED_CHAR(p[-1])) 48 49 /* Get a 2 byte signed integer. */ 50 #define COERCE16(x) ((int) (((x) ^ 0x8000) - 0x8000)) 51 #define NEXTWORD(p) \ 52 (p += 2, FETCH_DATA (info, p), \ 53 COERCE16 ((p[-1] << 8) + p[-2])) 54 55 /* Get a 4 byte signed integer. */ 56 #define COERCE32(x) ((int) (((x) ^ 0x80000000) - 0x80000000)) 57 #define NEXTLONG(p) \ 58 (p += 4, FETCH_DATA (info, p), \ 59 (COERCE32 ((((((p[-1] << 8) + p[-2]) << 8) + p[-3]) << 8) + p[-4]))) 60 61 /* Maximum length of an instruction. */ 62 #define MAXLEN 25 63 64 #include <setjmp.h> 65 66 struct private 67 { 68 /* Points to first byte not fetched. */ 69 bfd_byte *max_fetched; 70 bfd_byte the_buffer[MAXLEN]; 71 bfd_vma insn_start; 72 jmp_buf bailout; 73 }; 74 75 /* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive) 76 to ADDR (exclusive) are valid. Returns 1 for success, longjmps 77 on error. */ 78 #define FETCH_DATA(info, addr) \ 79 ((addr) <= ((struct private *)(info->private_data))->max_fetched \ 80 ? 1 : fetch_data ((info), (addr))) 81 82 static int 83 fetch_data (info, addr) 84 struct disassemble_info *info; 85 bfd_byte *addr; 86 { 87 int status; 88 struct private *priv = (struct private *) info->private_data; 89 bfd_vma start = priv->insn_start + (priv->max_fetched - priv->the_buffer); 90 91 status = (*info->read_memory_func) (start, 92 priv->max_fetched, 93 addr - priv->max_fetched, 94 info); 95 if (status != 0) 96 { 97 (*info->memory_error_func) (status, start, info); 98 longjmp (priv->bailout, 1); 99 } 100 else 101 priv->max_fetched = addr; 102 103 return 1; 104 } 105 106 /* Print the vax instruction at address MEMADDR in debugged memory, 107 on INFO->STREAM. Returns length of the instruction, in bytes. */ 108 109 int 110 print_insn_vax (memaddr, info) 111 bfd_vma memaddr; 112 disassemble_info *info; 113 { 114 const struct vot *votp; 115 const char *argp; 116 unsigned char *arg; 117 struct private priv; 118 bfd_byte *buffer = priv.the_buffer; 119 120 info->private_data = (PTR) &priv; 121 priv.max_fetched = priv.the_buffer; 122 priv.insn_start = memaddr; 123 124 if (setjmp (priv.bailout) != 0) 125 { 126 /* Error return. */ 127 return -1; 128 } 129 130 argp = NULL; 131 /* Check if the info buffer has more than one byte left since 132 the last opcode might be a single byte with no argument data. */ 133 if (info->buffer_length - (memaddr - info->buffer_vma) > 1) 134 { 135 FETCH_DATA (info, buffer + 2); 136 } 137 else 138 { 139 FETCH_DATA (info, buffer + 1); 140 buffer[1] = 0; 141 } 142 143 for (votp = &votstrs[0]; votp->name[0]; votp++) 144 { 145 register vax_opcodeT opcode = votp->detail.code; 146 147 /* 2 byte codes match 2 buffer pos. */ 148 if ((bfd_byte) opcode == buffer[0] 149 && (opcode >> 8 == 0 || opcode >> 8 == buffer[1])) 150 { 151 argp = votp->detail.args; 152 break; 153 } 154 } 155 if (argp == NULL) 156 { 157 /* Handle undefined instructions. */ 158 (*info->fprintf_func) (info->stream, ".word 0x%x", 159 (buffer[0] << 8) + buffer[1]); 160 return 2; 161 } 162 163 /* Point at first byte of argument data, and at descriptor for first 164 argument. */ 165 arg = buffer + ((votp->detail.code >> 8) ? 2 : 1); 166 167 /* Make sure we have it in mem */ 168 FETCH_DATA (info, arg); 169 170 (*info->fprintf_func) (info->stream, "%s", votp->name); 171 if (*argp) 172 (*info->fprintf_func) (info->stream, " "); 173 174 while (*argp) 175 { 176 arg += print_insn_arg (argp, arg, memaddr + arg - buffer, info); 177 argp += 2; 178 if (*argp) 179 (*info->fprintf_func) (info->stream, ","); 180 } 181 182 return arg - buffer; 183 } 184 185 /* Returns number of bytes "eaten" by the operand, or return -1 if an 186 invalid operand was found, or -2 if an opcode tabel error was 187 found. */ 188 189 static int 190 print_insn_arg (d, p0, addr, info) 191 const char *d; 192 unsigned char *p0; 193 bfd_vma addr; /* PC for this arg to be relative to */ 194 disassemble_info *info; 195 { 196 int arg_len; 197 198 /* check validity of addressing length */ 199 switch (d[1]) 200 { 201 case 'b' : arg_len = 1; break; 202 case 'd' : arg_len = 8; break; 203 case 'f' : arg_len = 4; break; 204 case 'g' : arg_len = 8; break; 205 case 'h' : arg_len = 16; break; 206 case 'l' : arg_len = 4; break; 207 case 'o' : arg_len = 16; break; 208 case 'w' : arg_len = 2; break; 209 case 'q' : arg_len = 8; break; 210 default : abort(); 211 } 212 213 /* branches have no mode byte */ 214 if (d[0] == 'b') 215 { 216 unsigned char *p = p0; 217 218 if (arg_len == 1) 219 (*info->print_address_func) (addr + 1 + NEXTBYTE (p), info); 220 else 221 (*info->print_address_func) (addr + 2 + NEXTWORD (p), info); 222 223 return p - p0; 224 } 225 226 return print_insn_mode (d, arg_len, p0, addr, info); 227 } 228 229 static int 230 print_insn_mode (d, size, p0, addr, info) 231 const char *d; 232 int size; 233 unsigned char *p0; 234 bfd_vma addr; /* PC for this arg to be relative to */ 235 disassemble_info *info; 236 { 237 unsigned char *p = p0; 238 unsigned char mode, reg; 239 240 /* fetch and interpret mode byte */ 241 mode = (unsigned char) NEXTBYTE (p); 242 reg = mode & 0xF; 243 switch (mode & 0xF0) 244 { 245 case 0x00: 246 case 0x10: 247 case 0x20: 248 case 0x30: /* literal mode $number */ 249 if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h') 250 (*info->fprintf_func) (info->stream, "$0x%x [%c-float]", mode, d[1]); 251 else 252 (*info->fprintf_func) (info->stream, "$0x%x", mode); 253 break; 254 case 0x40: /* index: base-addr[Rn] */ 255 p += print_insn_mode (d, size, p0 + 1, addr + 1, info); 256 (*info->fprintf_func) (info->stream, "[%s]", reg_names[reg]); 257 break; 258 case 0x50: /* register: Rn */ 259 (*info->fprintf_func) (info->stream, "%s", reg_names[reg]); 260 break; 261 case 0x60: /* register deferred: (Rn) */ 262 (*info->fprintf_func) (info->stream, "(%s)", reg_names[reg]); 263 break; 264 case 0x70: /* autodecrement: -(Rn) */ 265 (*info->fprintf_func) (info->stream, "-(%s)", reg_names[reg]); 266 break; 267 case 0x80: /* autoincrement: (Rn)+ */ 268 if (reg == 0xF) 269 { /* immediate? */ 270 int i; 271 272 FETCH_DATA (info, p + size); 273 (*info->fprintf_func) (info->stream, "$0x"); 274 if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h') 275 { 276 int float_word; 277 278 float_word = p[0] | (p[1] << 8); 279 if ((d[1] == 'd' || d[1] == 'f') 280 && (float_word & 0xff80) == 0x8000) 281 { 282 (*info->fprintf_func) (info->stream, "[invalid %c-float]", 283 d[1]); 284 } 285 else 286 { 287 for (i = 0; i < size; i++) 288 (*info->fprintf_func) (info->stream, "%02x", 289 p[size - i - 1]); 290 (*info->fprintf_func) (info->stream, " [%c-float]", d[1]); 291 } 292 } 293 else 294 { 295 for (i = 0; i < size; i++) 296 (*info->fprintf_func) (info->stream, "%02x", p[size - i - 1]); 297 } 298 p += size; 299 } 300 else 301 (*info->fprintf_func) (info->stream, "(%s)+", reg_names[reg]); 302 break; 303 case 0x90: /* autoincrement deferred: @(Rn)+ */ 304 if (reg == 0xF) 305 (*info->fprintf_func) (info->stream, "*0x%x", NEXTLONG (p)); 306 else 307 (*info->fprintf_func) (info->stream, "@(%s)+", reg_names[reg]); 308 break; 309 case 0xB0: /* displacement byte deferred: *displ(Rn) */ 310 (*info->fprintf_func) (info->stream, "*"); 311 case 0xA0: /* displacement byte: displ(Rn) */ 312 if (reg == 0xF) 313 (*info->print_address_func) (addr + 2 + NEXTBYTE (p), info); 314 else 315 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTBYTE (p), 316 reg_names[reg]); 317 break; 318 case 0xD0: /* displacement word deferred: *displ(Rn) */ 319 (*info->fprintf_func) (info->stream, "*"); 320 case 0xC0: /* displacement word: displ(Rn) */ 321 if (reg == 0xF) 322 (*info->print_address_func) (addr + 3 + NEXTWORD (p), info); 323 else 324 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTWORD (p), 325 reg_names[reg]); 326 break; 327 case 0xF0: /* displacement long deferred: *displ(Rn) */ 328 (*info->fprintf_func) (info->stream, "*"); 329 case 0xE0: /* displacement long: displ(Rn) */ 330 if (reg == 0xF) 331 (*info->print_address_func) (addr + 5 + NEXTLONG (p), info); 332 else 333 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTLONG (p), 334 reg_names[reg]); 335 break; 336 } 337 338 return p - p0; 339 } 340