| 1 | /* s390-dis.c -- Disassemble S390 instructions |
| 2 | Copyright 2000, 2001, 2002, 2003, 2005, 2007, 2008, 2012 |
| 3 | Free Software Foundation, Inc. |
| 4 | Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). |
| 5 | |
| 6 | This file is part of the GNU opcodes library. |
| 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 file; see the file COPYING. If not, write to the |
| 20 | Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, |
| 21 | MA 02110-1301, USA. */ |
| 22 | |
| 23 | #include "sysdep.h" |
| 24 | #include <stdio.h> |
| 25 | #include "ansidecl.h" |
| 26 | #include "dis-asm.h" |
| 27 | #include "opintl.h" |
| 28 | #include "opcode/s390.h" |
| 29 | |
| 30 | static int init_flag = 0; |
| 31 | static int opc_index[256]; |
| 32 | static int current_arch_mask = 0; |
| 33 | |
| 34 | /* Set up index table for first opcode byte. */ |
| 35 | |
| 36 | static void |
| 37 | init_disasm (struct disassemble_info *info) |
| 38 | { |
| 39 | const struct s390_opcode *opcode; |
| 40 | const struct s390_opcode *opcode_end; |
| 41 | const char *p; |
| 42 | |
| 43 | memset (opc_index, 0, sizeof (opc_index)); |
| 44 | opcode_end = s390_opcodes + s390_num_opcodes; |
| 45 | for (opcode = s390_opcodes; opcode < opcode_end; opcode++) |
| 46 | { |
| 47 | opc_index[(int) opcode->opcode[0]] = opcode - s390_opcodes; |
| 48 | while ((opcode < opcode_end) && |
| 49 | (opcode[1].opcode[0] == opcode->opcode[0])) |
| 50 | opcode++; |
| 51 | } |
| 52 | |
| 53 | for (p = info->disassembler_options; p != NULL; ) |
| 54 | { |
| 55 | if (CONST_STRNEQ (p, "esa")) |
| 56 | current_arch_mask = 1 << S390_OPCODE_ESA; |
| 57 | else if (CONST_STRNEQ (p, "zarch")) |
| 58 | current_arch_mask = 1 << S390_OPCODE_ZARCH; |
| 59 | else |
| 60 | fprintf (stderr, "Unknown S/390 disassembler option: %s\n", p); |
| 61 | |
| 62 | p = strchr (p, ','); |
| 63 | if (p != NULL) |
| 64 | p++; |
| 65 | } |
| 66 | |
| 67 | if (!current_arch_mask) |
| 68 | current_arch_mask = 1 << S390_OPCODE_ZARCH; |
| 69 | |
| 70 | init_flag = 1; |
| 71 | } |
| 72 | |
| 73 | /* Extracts an operand value from an instruction. */ |
| 74 | /* We do not perform the shift operation for larl-type address |
| 75 | operands here since that would lead to an overflow of the 32 bit |
| 76 | integer value. Instead the shift operation is done when printing |
| 77 | the operand in print_insn_s390. */ |
| 78 | |
| 79 | static inline unsigned int |
| 80 | s390_extract_operand (unsigned char *insn, const struct s390_operand *operand) |
| 81 | { |
| 82 | unsigned int val; |
| 83 | int bits; |
| 84 | |
| 85 | /* Extract fragments of the operand byte for byte. */ |
| 86 | insn += operand->shift / 8; |
| 87 | bits = (operand->shift & 7) + operand->bits; |
| 88 | val = 0; |
| 89 | do |
| 90 | { |
| 91 | val <<= 8; |
| 92 | val |= (unsigned int) *insn++; |
| 93 | bits -= 8; |
| 94 | } |
| 95 | while (bits > 0); |
| 96 | val >>= -bits; |
| 97 | val &= ((1U << (operand->bits - 1)) << 1) - 1; |
| 98 | |
| 99 | /* Check for special long displacement case. */ |
| 100 | if (operand->bits == 20 && operand->shift == 20) |
| 101 | val = (val & 0xff) << 12 | (val & 0xfff00) >> 8; |
| 102 | |
| 103 | /* Sign extend value if the operand is signed or pc relative. */ |
| 104 | if ((operand->flags & (S390_OPERAND_SIGNED | S390_OPERAND_PCREL)) |
| 105 | && (val & (1U << (operand->bits - 1)))) |
| 106 | val |= (-1U << (operand->bits - 1)) << 1; |
| 107 | |
| 108 | /* Length x in an instructions has real length x + 1. */ |
| 109 | if (operand->flags & S390_OPERAND_LENGTH) |
| 110 | val++; |
| 111 | return val; |
| 112 | } |
| 113 | |
| 114 | /* Print a S390 instruction. */ |
| 115 | |
| 116 | int |
| 117 | print_insn_s390 (bfd_vma memaddr, struct disassemble_info *info) |
| 118 | { |
| 119 | bfd_byte buffer[6]; |
| 120 | const struct s390_opcode *opcode; |
| 121 | const struct s390_opcode *opcode_end; |
| 122 | unsigned int value; |
| 123 | int status, opsize, bufsize; |
| 124 | char separator; |
| 125 | |
| 126 | if (init_flag == 0) |
| 127 | init_disasm (info); |
| 128 | |
| 129 | /* The output looks better if we put 6 bytes on a line. */ |
| 130 | info->bytes_per_line = 6; |
| 131 | |
| 132 | /* Every S390 instruction is max 6 bytes long. */ |
| 133 | memset (buffer, 0, 6); |
| 134 | status = (*info->read_memory_func) (memaddr, buffer, 6, info); |
| 135 | if (status != 0) |
| 136 | { |
| 137 | for (bufsize = 0; bufsize < 6; bufsize++) |
| 138 | if ((*info->read_memory_func) (memaddr, buffer, bufsize + 1, info) != 0) |
| 139 | break; |
| 140 | if (bufsize <= 0) |
| 141 | { |
| 142 | (*info->memory_error_func) (status, memaddr, info); |
| 143 | return -1; |
| 144 | } |
| 145 | /* Opsize calculation looks strange but it works |
| 146 | 00xxxxxx -> 2 bytes, 01xxxxxx/10xxxxxx -> 4 bytes, |
| 147 | 11xxxxxx -> 6 bytes. */ |
| 148 | opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1; |
| 149 | status = opsize > bufsize; |
| 150 | } |
| 151 | else |
| 152 | { |
| 153 | bufsize = 6; |
| 154 | opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1; |
| 155 | } |
| 156 | |
| 157 | if (status == 0) |
| 158 | { |
| 159 | const struct s390_opcode *op; |
| 160 | |
| 161 | /* Find the first match in the opcode table. */ |
| 162 | opcode_end = s390_opcodes + s390_num_opcodes; |
| 163 | for (opcode = s390_opcodes + opc_index[(int) buffer[0]]; |
| 164 | (opcode < opcode_end) && (buffer[0] == opcode->opcode[0]); |
| 165 | opcode++) |
| 166 | { |
| 167 | const struct s390_operand *operand; |
| 168 | const unsigned char *opindex; |
| 169 | |
| 170 | /* Check architecture. */ |
| 171 | if (!(opcode->modes & current_arch_mask)) |
| 172 | continue; |
| 173 | |
| 174 | /* Check signature of the opcode. */ |
| 175 | if ((buffer[1] & opcode->mask[1]) != opcode->opcode[1] |
| 176 | || (buffer[2] & opcode->mask[2]) != opcode->opcode[2] |
| 177 | || (buffer[3] & opcode->mask[3]) != opcode->opcode[3] |
| 178 | || (buffer[4] & opcode->mask[4]) != opcode->opcode[4] |
| 179 | || (buffer[5] & opcode->mask[5]) != opcode->opcode[5]) |
| 180 | continue; |
| 181 | |
| 182 | /* Advance to an opcode with a more specific mask. */ |
| 183 | for (op = opcode + 1; op < opcode_end; op++) |
| 184 | { |
| 185 | if ((buffer[0] & op->mask[0]) != op->opcode[0]) |
| 186 | break; |
| 187 | |
| 188 | if ((buffer[1] & op->mask[1]) != op->opcode[1] |
| 189 | || (buffer[2] & op->mask[2]) != op->opcode[2] |
| 190 | || (buffer[3] & op->mask[3]) != op->opcode[3] |
| 191 | || (buffer[4] & op->mask[4]) != op->opcode[4] |
| 192 | || (buffer[5] & op->mask[5]) != op->opcode[5]) |
| 193 | continue; |
| 194 | |
| 195 | if (((int)opcode->mask[0] + opcode->mask[1] + |
| 196 | opcode->mask[2] + opcode->mask[3] + |
| 197 | opcode->mask[4] + opcode->mask[5]) < |
| 198 | ((int)op->mask[0] + op->mask[1] + |
| 199 | op->mask[2] + op->mask[3] + |
| 200 | op->mask[4] + op->mask[5])) |
| 201 | opcode = op; |
| 202 | } |
| 203 | |
| 204 | /* The instruction is valid. */ |
| 205 | if (opcode->operands[0] != 0) |
| 206 | (*info->fprintf_func) (info->stream, "%s\t", opcode->name); |
| 207 | else |
| 208 | (*info->fprintf_func) (info->stream, "%s", opcode->name); |
| 209 | |
| 210 | /* Extract the operands. */ |
| 211 | separator = 0; |
| 212 | for (opindex = opcode->operands; *opindex != 0; opindex++) |
| 213 | { |
| 214 | operand = s390_operands + *opindex; |
| 215 | value = s390_extract_operand (buffer, operand); |
| 216 | |
| 217 | if ((operand->flags & S390_OPERAND_INDEX) && value == 0) |
| 218 | continue; |
| 219 | if ((operand->flags & S390_OPERAND_BASE) && |
| 220 | value == 0 && separator == '(') |
| 221 | { |
| 222 | separator = ','; |
| 223 | continue; |
| 224 | } |
| 225 | |
| 226 | if (separator) |
| 227 | (*info->fprintf_func) (info->stream, "%c", separator); |
| 228 | |
| 229 | if (operand->flags & S390_OPERAND_GPR) |
| 230 | (*info->fprintf_func) (info->stream, "%%r%i", value); |
| 231 | else if (operand->flags & S390_OPERAND_FPR) |
| 232 | (*info->fprintf_func) (info->stream, "%%f%i", value); |
| 233 | else if (operand->flags & S390_OPERAND_AR) |
| 234 | (*info->fprintf_func) (info->stream, "%%a%i", value); |
| 235 | else if (operand->flags & S390_OPERAND_CR) |
| 236 | (*info->fprintf_func) (info->stream, "%%c%i", value); |
| 237 | else if (operand->flags & S390_OPERAND_PCREL) |
| 238 | (*info->print_address_func) (memaddr + (int)value + (int)value, |
| 239 | info); |
| 240 | else if (operand->flags & S390_OPERAND_SIGNED) |
| 241 | (*info->fprintf_func) (info->stream, "%i", (int) value); |
| 242 | else |
| 243 | (*info->fprintf_func) (info->stream, "%u", value); |
| 244 | |
| 245 | if (operand->flags & S390_OPERAND_DISP) |
| 246 | { |
| 247 | separator = '('; |
| 248 | } |
| 249 | else if (operand->flags & S390_OPERAND_BASE) |
| 250 | { |
| 251 | (*info->fprintf_func) (info->stream, ")"); |
| 252 | separator = ','; |
| 253 | } |
| 254 | else |
| 255 | separator = ','; |
| 256 | } |
| 257 | |
| 258 | /* Found instruction, printed it, return its size. */ |
| 259 | return opsize; |
| 260 | } |
| 261 | /* No matching instruction found, fall through to hex print. */ |
| 262 | } |
| 263 | |
| 264 | if (bufsize >= 4) |
| 265 | { |
| 266 | value = (unsigned int) buffer[0]; |
| 267 | value = (value << 8) + (unsigned int) buffer[1]; |
| 268 | value = (value << 8) + (unsigned int) buffer[2]; |
| 269 | value = (value << 8) + (unsigned int) buffer[3]; |
| 270 | (*info->fprintf_func) (info->stream, ".long\t0x%08x", value); |
| 271 | return 4; |
| 272 | } |
| 273 | else if (bufsize >= 2) |
| 274 | { |
| 275 | value = (unsigned int) buffer[0]; |
| 276 | value = (value << 8) + (unsigned int) buffer[1]; |
| 277 | (*info->fprintf_func) (info->stream, ".short\t0x%04x", value); |
| 278 | return 2; |
| 279 | } |
| 280 | else |
| 281 | { |
| 282 | value = (unsigned int) buffer[0]; |
| 283 | (*info->fprintf_func) (info->stream, ".byte\t0x%02x", value); |
| 284 | return 1; |
| 285 | } |
| 286 | } |
| 287 | |
| 288 | void |
| 289 | print_s390_disassembler_options (FILE *stream) |
| 290 | { |
| 291 | fprintf (stream, _("\n\ |
| 292 | The following S/390 specific disassembler options are supported for use\n\ |
| 293 | with the -M switch (multiple options should be separated by commas):\n")); |
| 294 | |
| 295 | fprintf (stream, _(" esa Disassemble in ESA architecture mode\n")); |
| 296 | fprintf (stream, _(" zarch Disassemble in z/Architecture mode\n")); |
| 297 | } |