1 /* Print VAX instructions. 2 Copyright (C) 1995, 1998 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 25 print_insn_arg PARAMS ((const char *, unsigned char *, bfd_vma, 26 disassemble_info *)); 27 28 static int 29 print_insn_mode PARAMS ((int, unsigned char *, bfd_vma, disassemble_info *)); 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 = NULL; 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 if (setjmp (priv.bailout) != 0) 124 { 125 /* Error return. */ 126 return -1; 127 } 128 129 FETCH_DATA (info, buffer + 2); 130 for (votp = &votstrs[0]; votp->name[0]; votp++) 131 { 132 register vax_opcodeT opcode = votp->detail.code; 133 134 /* 2 byte codes match 2 buffer pos. */ 135 if ((bfd_byte) opcode == buffer[0] 136 && (opcode >> 8 == 0 || opcode >> 8 == buffer[1])) 137 { 138 argp = votp->detail.args; 139 break; 140 } 141 } 142 if (argp == NULL) 143 { 144 /* Handle undefined instructions. */ 145 (*info->fprintf_func) (info->stream, ".word 0x%x", 146 (buffer[0] << 8) + buffer[1]); 147 return 2; 148 } 149 150 /* Point at first byte of argument data, and at descriptor for first 151 argument. */ 152 arg = buffer + ((votp->detail.code >> 8) ? 2 : 1); 153 154 /* Make sure we have it in mem */ 155 FETCH_DATA (info, arg); 156 157 (*info->fprintf_func) (info->stream, "%s", votp->name); 158 if (*argp) 159 (*info->fprintf_func) (info->stream, " "); 160 161 while (*argp) 162 { 163 arg += print_insn_arg (argp, arg, memaddr + arg - buffer, info); 164 argp += 2; 165 if (*argp) 166 (*info->fprintf_func) (info->stream, ","); 167 } 168 169 return arg - buffer; 170 } 171 172 /* Returns number of bytes "eaten" by the operand, or return -1 if an 173 invalid operand was found, or -2 if an opcode tabel error was 174 found. */ 175 176 static int 177 print_insn_arg (d, p0, addr, info) 178 const char *d; 179 unsigned char *p0; 180 bfd_vma addr; /* PC for this arg to be relative to */ 181 disassemble_info *info; 182 { 183 int arg_len; 184 185 /* check validity of addressing length */ 186 switch (d[1]) 187 { 188 case 'b' : arg_len = 1; break; 189 case 'd' : arg_len = 8; break; 190 case 'f' : arg_len = 4; break; 191 case 'g' : arg_len = 8; break; 192 case 'h' : arg_len = 16; break; 193 case 'l' : arg_len = 4; break; 194 case 'o' : arg_len = 16; break; 195 case 'w' : arg_len = 2; break; 196 case 'q' : arg_len = 8; break; 197 default : abort(); 198 } 199 200 /* branches have no mode byte */ 201 if (d[0] == 'b') 202 { 203 unsigned char *p = p0; 204 205 if (arg_len == 1) 206 (*info->print_address_func) (addr + 1 + NEXTBYTE (p), info); 207 else 208 (*info->print_address_func) (addr + 2 + NEXTWORD (p), info); 209 210 return p - p0; 211 } 212 213 return print_insn_mode (arg_len, p0, addr, info); 214 } 215 216 static int 217 print_insn_mode (size, p0, addr, info) 218 int size; 219 unsigned char *p0; 220 bfd_vma addr; /* PC for this arg to be relative to */ 221 disassemble_info *info; 222 { 223 unsigned char *p = p0; 224 unsigned char mode, reg; 225 226 /* fetch and interpret mode byte */ 227 mode = (unsigned char) NEXTBYTE (p); 228 reg = mode & 0xF; 229 switch (mode & 0xF0) 230 { 231 case 0x00: 232 case 0x10: 233 case 0x20: 234 case 0x30: /* literal mode $number */ 235 (*info->fprintf_func) (info->stream, "$0x%x", mode); 236 break; 237 case 0x40: /* index: base-addr[Rn] */ 238 p += print_insn_mode (size, p0 + 1, addr + 1, info); 239 (*info->fprintf_func) (info->stream, "[%s]", reg_names[reg]); 240 break; 241 case 0x50: /* register: Rn */ 242 (*info->fprintf_func) (info->stream, "%s", reg_names[reg]); 243 break; 244 case 0x60: /* register deferred: (Rn) */ 245 (*info->fprintf_func) (info->stream, "(%s)", reg_names[reg]); 246 break; 247 case 0x70: /* autodecrement: -(Rn) */ 248 (*info->fprintf_func) (info->stream, "-(%s)", reg_names[reg]); 249 break; 250 case 0x80: /* autoincrement: (Rn)+ */ 251 if (reg == 0xF) 252 { /* immediate? */ 253 int i; 254 255 FETCH_DATA (info, p + size); 256 (*info->fprintf_func) (info->stream, "$0x"); 257 for (i = 0; i < size; i++) 258 (*info->fprintf_func) (info->stream, "%02x", p[size - i - 1]); 259 p += size; 260 } 261 else 262 (*info->fprintf_func) (info->stream, "(%s)+", reg_names[reg]); 263 break; 264 case 0x90: /* autoincrement deferred: @(Rn)+ */ 265 if (reg == 0xF) 266 (*info->fprintf_func) (info->stream, "*0x%x", NEXTLONG (p)); 267 else 268 (*info->fprintf_func) (info->stream, "@(%s)+", reg_names[reg]); 269 break; 270 case 0xB0: /* displacement byte deferred: *displ(Rn) */ 271 (*info->fprintf_func) (info->stream, "*"); 272 case 0xA0: /* displacement byte: displ(Rn) */ 273 if (reg == 0xF) 274 (*info->print_address_func) (addr + 2 + NEXTBYTE (p), info); 275 else 276 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTBYTE (p), 277 reg_names[reg]); 278 break; 279 case 0xD0: /* displacement word deferred: *displ(Rn) */ 280 (*info->fprintf_func) (info->stream, "*"); 281 case 0xC0: /* displacement word: displ(Rn) */ 282 if (reg == 0xF) 283 (*info->print_address_func) (addr + 3 + NEXTWORD (p), info); 284 else 285 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTWORD (p), 286 reg_names[reg]); 287 break; 288 case 0xF0: /* displacement long deferred: *displ(Rn) */ 289 (*info->fprintf_func) (info->stream, "*"); 290 case 0xE0: /* displacement long: displ(Rn) */ 291 if (reg == 0xF) 292 (*info->print_address_func) (addr + 5 + NEXTLONG (p), info); 293 else 294 (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTLONG (p), 295 reg_names[reg]); 296 break; 297 } 298 299 return p - p0; 300 } 301