1 /* Print i386 instructions for GDB, the GNU debugger.
2 Copyright (C) 1988, 1989, 1991 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
26 * The main tables describing the instructions is essentially a copy
27 * of the "Opcode Map" chapter (Appendix A) of the Intel 80386
28 * Programmers Manual. Usually, there is a capital letter, followed
29 * by a small letter. The capital letter tell the addressing mode,
30 * and the small letter tells about the operand size. Refer to
31 * the Intel manual for details.
37 /* For the GDB interface at the bottom of the file... */
41 #define Eb OP_E, b_mode
42 #define indirEb OP_indirE, b_mode
43 #define Gb OP_G, b_mode
44 #define Ev OP_E, v_mode
45 #define indirEv OP_indirE, v_mode
46 #define Ew OP_E, w_mode
47 #define Ma OP_E, v_mode
49 #define Mp OP_E, 0 /* ? */
50 #define Gv OP_G, v_mode
51 #define Gw OP_G, w_mode
52 #define Rw OP_rm, w_mode
53 #define Rd OP_rm, d_mode
54 #define Ib OP_I, b_mode
55 #define sIb OP_sI, b_mode /* sign extened byte */
56 #define Iv OP_I, v_mode
57 #define Iw OP_I, w_mode
58 #define Jb OP_J, b_mode
59 #define Jv OP_J, v_mode
61 #define Cd OP_C, d_mode
62 #define Dd OP_D, d_mode
63 #define Td OP_T, d_mode
65 #define eAX OP_REG, eAX_reg
66 #define eBX OP_REG, eBX_reg
67 #define eCX OP_REG, eCX_reg
68 #define eDX OP_REG, eDX_reg
69 #define eSP OP_REG, eSP_reg
70 #define eBP OP_REG, eBP_reg
71 #define eSI OP_REG, eSI_reg
72 #define eDI OP_REG, eDI_reg
73 #define AL OP_REG, al_reg
74 #define CL OP_REG, cl_reg
75 #define DL OP_REG, dl_reg
76 #define BL OP_REG, bl_reg
77 #define AH OP_REG, ah_reg
78 #define CH OP_REG, ch_reg
79 #define DH OP_REG, dh_reg
80 #define BH OP_REG, bh_reg
81 #define AX OP_REG, ax_reg
82 #define DX OP_REG, dx_reg
83 #define indirDX OP_REG, indir_dx_reg
85 #define Sw OP_SEG, w_mode
86 #define Ap OP_DIR, lptr
87 #define Av OP_DIR, v_mode
88 #define Ob OP_OFF, b_mode
89 #define Ov OP_OFF, v_mode
90 #define Xb OP_DSSI, b_mode
91 #define Xv OP_DSSI, v_mode
92 #define Yb OP_ESDI, b_mode
93 #define Yv OP_ESDI, v_mode
95 #define es OP_REG, es_reg
96 #define ss OP_REG, ss_reg
97 #define cs OP_REG, cs_reg
98 #define ds OP_REG, ds_reg
99 #define fs OP_REG, fs_reg
100 #define gs OP_REG, gs_reg
102 int OP_E(), OP_indirE(), OP_G(), OP_I(), OP_sI(), OP_REG();
103 int OP_J(), OP_SEG();
104 int OP_DIR(), OP_OFF(), OP_DSSI(), OP_ESDI(), OP_ONE(), OP_C();
105 int OP_D(), OP_T(), OP_rm();
148 #define indir_dx_reg 150
150 #define GRP1b NULL, NULL, 0
151 #define GRP1S NULL, NULL, 1
152 #define GRP1Ss NULL, NULL, 2
153 #define GRP2b NULL, NULL, 3
154 #define GRP2S NULL, NULL, 4
155 #define GRP2b_one NULL, NULL, 5
156 #define GRP2S_one NULL, NULL, 6
157 #define GRP2b_cl NULL, NULL, 7
158 #define GRP2S_cl NULL, NULL, 8
159 #define GRP3b NULL, NULL, 9
160 #define GRP3S NULL, NULL, 10
161 #define GRP4 NULL, NULL, 11
162 #define GRP5 NULL, NULL, 12
163 #define GRP6 NULL, NULL, 13
164 #define GRP7 NULL, NULL, 14
165 #define GRP8 NULL, NULL, 15
168 #define FLOAT NULL, NULL, FLOATCODE
180 struct dis386 dis386[] = {
198 { "(bad)" }, /* 0x0f extended opcode escape */
224 { "(bad)" }, /* SEG ES prefix */
233 { "(bad)" }, /* SEG CS prefix */
242 { "(bad)" }, /* SEG SS prefix */
251 { "(bad)" }, /* SEG DS prefix */
292 { "boundS", Gv, Ma },
294 { "(bad)" }, /* seg fs */
295 { "(bad)" }, /* seg gs */
296 { "(bad)" }, /* op size prefix */
297 { "(bad)" }, /* adr size prefix */
299 { "pushS", Iv }, /* 386 book wrong */
300 { "imulS", Gv, Ev, Iv },
301 { "pushl", sIb }, /* push of byte really pushes 4 bytes */
302 { "imulS", Gv, Ev, Ib },
303 { "insb", Yb, indirDX },
304 { "insS", Yv, indirDX },
305 { "outsb", indirDX, Xb },
306 { "outsS", indirDX, Xv },
345 { "xchgS", eCX, eAX },
346 { "xchgS", eDX, eAX },
347 { "xchgS", eBX, eAX },
348 { "xchgS", eSP, eAX },
349 { "xchgS", eBP, eAX },
350 { "xchgS", eSI, eAX },
351 { "xchgS", eDI, eAX },
356 { "(bad)" }, /* fwait */
372 { "testS", eAX, Iv },
374 { "stosS", Yv, eAX },
376 { "lodsS", eAX, Xv },
378 { "scasS", eAX, Xv },
447 { "inb", AL, indirDX },
448 { "inS", eAX, indirDX },
449 { "outb", indirDX, AL },
450 { "outS", indirDX, eAX },
452 { "(bad)" }, /* lock prefix */
454 { "(bad)" }, /* repne */
455 { "(bad)" }, /* repz */
471 struct dis386 dis386_twobyte[] = {
482 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
483 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
485 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
486 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
488 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
489 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
491 /* these are all backward in appendix A of the intel book */
501 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
502 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
504 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
505 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
507 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
508 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
510 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
511 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
513 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
514 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
516 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
517 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
519 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
520 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
522 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
523 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
525 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
526 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
528 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
529 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
531 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
532 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
574 { "shldS", Ev, Gv, Ib },
575 { "shldS", Ev, Gv, CL },
583 { "shrdS", Ev, Gv, Ib },
584 { "shrdS", Ev, Gv, CL },
590 { "lssS", Gv, Mp }, /* 386 lists only Mp */
592 { "lfsS", Gv, Mp }, /* 386 lists only Mp */
593 { "lgsS", Gv, Mp }, /* 386 lists only Mp */
594 { "movzbS", Gv, Eb },
595 { "movzwS", Gv, Ew },
603 { "movsbS", Gv, Eb },
604 { "movswS", Gv, Ew },
606 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
607 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
609 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
610 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
612 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
613 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
615 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
616 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
618 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
619 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
621 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
622 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
624 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
625 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
627 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
628 { "(bad)" }, { "(bad)" }, { "(bad)" }, { "(bad)" },
631 static char obuf[100];
633 static char scratchbuf[100];
634 static unsigned char *start_codep;
635 static unsigned char *codep;
639 static void oappend ();
641 static char *names32[]={
642 "%eax","%ecx","%edx","%ebx", "%esp","%ebp","%esi","%edi",
644 static char *names16[] = {
645 "%ax","%cx","%dx","%bx","%sp","%bp","%si","%di",
647 static char *names8[] = {
648 "%al","%cl","%dl","%bl","%ah","%ch","%dh","%bh",
650 static char *names_seg[] = {
651 "%es","%cs","%ss","%ds","%fs","%gs","%?","%?",
654 struct dis386 grps[][8] = {
772 { "imulS", eAX, Ev },
774 { "idivS", eAX, Ev },
792 { "lcall", indirEv },
833 #define PREFIX_REPZ 1
834 #define PREFIX_REPNZ 2
835 #define PREFIX_LOCK 4
837 #define PREFIX_SS 0x10
838 #define PREFIX_DS 0x20
839 #define PREFIX_ES 0x40
840 #define PREFIX_FS 0x80
841 #define PREFIX_GS 0x100
842 #define PREFIX_DATA 0x200
843 #define PREFIX_ADR 0x400
844 #define PREFIX_FWAIT 0x800
856 prefixes |= PREFIX_REPZ;
859 prefixes |= PREFIX_REPNZ;
862 prefixes |= PREFIX_LOCK;
865 prefixes |= PREFIX_CS;
868 prefixes |= PREFIX_SS;
871 prefixes |= PREFIX_DS;
874 prefixes |= PREFIX_ES;
877 prefixes |= PREFIX_FS;
880 prefixes |= PREFIX_GS;
883 prefixes |= PREFIX_DATA;
886 prefixes |= PREFIX_ADR;
889 prefixes |= PREFIX_FWAIT;
901 static char op1out[100], op2out[100], op3out[100];
902 static int op_address[3], op_ad, op_index[3];
904 extern void fputs_filtered ();
907 * disassemble the first instruction in 'inbuf'. You have to make
908 * sure all of the bytes of the instruction are filled in.
909 * On the 386's of 1988, the maximum length of an instruction is 15 bytes.
910 * (see topic "Redundant prefixes" in the "Differences from 8086"
911 * section of the "Virtual 8086 Mode" chapter.)
912 * 'pc' should be the address of this instruction, it will
913 * be used to print the target address if this is a relative jump or call
914 * 'outbuf' gets filled in with the disassembled instruction. it should
915 * be long enough to hold the longest disassembled instruction.
916 * 100 bytes is certainly enough, unless symbol printing is added later
917 * The function returns the length of this instruction in bytes.
919 i386dis (pc, inbuf, stream)
921 unsigned char *inbuf;
927 int enter_instruction;
928 char *first, *second, *third;
936 op_index[0] = op_index[1] = op_index[2] = -1;
945 enter_instruction = 1;
947 enter_instruction = 0;
951 if (prefixes & PREFIX_REPZ)
953 if (prefixes & PREFIX_REPNZ)
955 if (prefixes & PREFIX_LOCK)
958 if ((prefixes & PREFIX_FWAIT)
959 && ((*codep < 0xd8) || (*codep > 0xdf)))
961 /* fwait not followed by floating point instruction */
962 fputs_filtered ("fwait", stream);
966 /* these would be initialized to 0 if disassembling for 8086 or 286 */
970 if (prefixes & PREFIX_DATA)
973 if (prefixes & PREFIX_ADR)
980 dp = &dis386_twobyte[*++codep];
982 dp = &dis386[*codep];
984 mod = (*codep >> 6) & 3;
985 reg = (*codep >> 3) & 7;
988 if (dp->name == NULL && dp->bytemode1 == FLOATCODE)
994 if (dp->name == NULL)
995 dp = &grps[dp->bytemode1][reg];
1002 (*dp->op1)(dp->bytemode1);
1007 (*dp->op2)(dp->bytemode2);
1012 (*dp->op3)(dp->bytemode3);
1015 obufp = obuf + strlen (obuf);
1016 for (i = strlen (obuf); i < 6; i++)
1019 fputs_filtered (obuf, stream);
1021 /* enter instruction is printed with operands in the
1022 * same order as the intel book; everything else
1023 * is printed in reverse order
1025 if (enter_instruction)
1030 op_ad = op_index[0];
1031 op_index[0] = op_index[2];
1032 op_index[2] = op_ad;
1043 if (op_index[0] != -1)
1044 print_address (op_address[op_index[0]], stream);
1046 fputs_filtered (first, stream);
1052 fputs_filtered (",", stream);
1053 if (op_index[1] != -1)
1054 print_address (op_address[op_index[1]], stream);
1056 fputs_filtered (second, stream);
1062 fputs_filtered (",", stream);
1063 if (op_index[2] != -1)
1064 print_address (op_address[op_index[2]], stream);
1066 fputs_filtered (third, stream);
1068 return (codep - inbuf);
1071 char *float_mem[] = {
1147 #define STi OP_STi, 0
1148 int OP_ST(), OP_STi();
1150 #define FGRPd9_2 NULL, NULL, 0
1151 #define FGRPd9_4 NULL, NULL, 1
1152 #define FGRPd9_5 NULL, NULL, 2
1153 #define FGRPd9_6 NULL, NULL, 3
1154 #define FGRPd9_7 NULL, NULL, 4
1155 #define FGRPda_5 NULL, NULL, 5
1156 #define FGRPdb_4 NULL, NULL, 6
1157 #define FGRPde_3 NULL, NULL, 7
1158 #define FGRPdf_4 NULL, NULL, 8
1160 struct dis386 float_reg[][8] = {
1163 { "fadd", ST, STi },
1164 { "fmul", ST, STi },
1167 { "fsub", ST, STi },
1168 { "fsubr", ST, STi },
1169 { "fdiv", ST, STi },
1170 { "fdivr", ST, STi },
1207 { "fadd", STi, ST },
1208 { "fmul", STi, ST },
1211 { "fsub", STi, ST },
1212 { "fsubr", STi, ST },
1213 { "fdiv", STi, ST },
1214 { "fdivr", STi, ST },
1229 { "faddp", STi, ST },
1230 { "fmulp", STi, ST },
1233 { "fsubp", STi, ST },
1234 { "fsubrp", STi, ST },
1235 { "fdivp", STi, ST },
1236 { "fdivrp", STi, ST },
1252 char *fgrps[][8] = {
1255 "fnop","(bad)","(bad)","(bad)","(bad)","(bad)","(bad)","(bad)",
1260 "fchs","fabs","(bad)","(bad)","ftst","fxam","(bad)","(bad)",
1265 "fld1","fldl2t","fldl2e","fldpi","fldlg2","fldln2","fldz","(bad)",
1270 "f2xm1","fyl2x","fptan","fpatan","fxtract","fprem1","fdecstp","fincstp",
1275 "fprem","fyl2xp1","fsqrt","fsincos","frndint","fscale","fsin","fcos",
1280 "(bad)","fucompp","(bad)","(bad)","(bad)","(bad)","(bad)","(bad)",
1285 "feni(287 only)","fdisi(287 only)","fNclex","fNinit",
1286 "fNsetpm(287 only)","(bad)","(bad)","(bad)",
1291 "(bad)","fcompp","(bad)","(bad)","(bad)","(bad)","(bad)","(bad)",
1296 "fNstsw","(bad)","(bad)","(bad)","(bad)","(bad)","(bad)","(bad)",
1304 unsigned char floatop;
1306 floatop = codep[-1];
1310 putop (float_mem[(floatop - 0xd8) * 8 + reg]);
1317 dp = &float_reg[floatop - 0xd8][reg];
1318 if (dp->name == NULL)
1320 putop (fgrps[dp->bytemode1][rm]);
1321 /* instruction fnstsw is only one with strange arg */
1322 if (floatop == 0xdf && *codep == 0xe0)
1323 strcpy (op1out, "%eax");
1330 (*dp->op1)(dp->bytemode1);
1333 (*dp->op2)(dp->bytemode2);
1346 sprintf (scratchbuf, "%%st(%d)", rm);
1347 oappend (scratchbuf);
1351 /* capital letters in template are macros */
1357 for (p = template; *p; p++)
1364 case 'C': /* For jcxz/jecxz */
1369 if ((prefixes & PREFIX_FWAIT) == 0)
1373 /* operand size flag */
1389 obufp += strlen (s);
1395 if (prefixes & PREFIX_CS)
1397 if (prefixes & PREFIX_DS)
1399 if (prefixes & PREFIX_SS)
1401 if (prefixes & PREFIX_ES)
1403 if (prefixes & PREFIX_FS)
1405 if (prefixes & PREFIX_GS)
1409 OP_indirE (bytemode)
1425 /* skip mod/rm byte */
1437 oappend (names8[rm]);
1440 oappend (names16[rm]);
1444 oappend (names32[rm]);
1446 oappend (names16[rm]);
1449 oappend ("<bad dis table>");
1460 scale = (*codep >> 6) & 3;
1461 index = (*codep >> 3) & 7;
1472 /* implies havesib and havebase */
1488 disp = *(char *)codep++;
1505 if (mod != 0 || rm == 5 || (havesib && base == 5))
1507 sprintf (scratchbuf, "0x%x", disp);
1508 oappend (scratchbuf);
1511 if (havebase || havesib)
1515 oappend (names32[base]);
1520 sprintf (scratchbuf, ",%s", names32[index]);
1521 oappend (scratchbuf);
1523 sprintf (scratchbuf, ",%d", 1 << scale);
1524 oappend (scratchbuf);
1535 oappend (names8[reg]);
1538 oappend (names16[reg]);
1541 oappend (names32[reg]);
1545 oappend (names32[reg]);
1547 oappend (names16[reg]);
1550 oappend ("<internal disassembler error>");
1559 x = *codep++ & 0xff;
1560 x |= (*codep++ & 0xff) << 8;
1561 x |= (*codep++ & 0xff) << 16;
1562 x |= (*codep++ & 0xff) << 24;
1570 x = *codep++ & 0xff;
1571 x |= (*codep++ & 0xff) << 8;
1578 op_index[op_ad] = op_ad;
1579 op_address[op_ad] = op;
1588 case indir_dx_reg: s = "(%dx)"; break;
1589 case ax_reg: case cx_reg: case dx_reg: case bx_reg:
1590 case sp_reg: case bp_reg: case si_reg: case di_reg:
1591 s = names16[code - ax_reg];
1593 case es_reg: case ss_reg: case cs_reg:
1594 case ds_reg: case fs_reg: case gs_reg:
1595 s = names_seg[code - es_reg];
1597 case al_reg: case ah_reg: case cl_reg: case ch_reg:
1598 case dl_reg: case dh_reg: case bl_reg: case bh_reg:
1599 s = names8[code - al_reg];
1601 case eAX_reg: case eCX_reg: case eDX_reg: case eBX_reg:
1602 case eSP_reg: case eBP_reg: case eSI_reg: case eDI_reg:
1604 s = names32[code - eAX_reg];
1606 s = names16[code - eAX_reg];
1609 s = "<internal disassembler error>";
1622 op = *codep++ & 0xff;
1634 oappend ("<internal disassembler error>");
1637 sprintf (scratchbuf, "$0x%x", op);
1638 oappend (scratchbuf);
1648 op = *(char *)codep++;
1654 op = (short)get16();
1657 op = (short)get16 ();
1660 oappend ("<internal disassembler error>");
1663 sprintf (scratchbuf, "$0x%x", op);
1664 oappend (scratchbuf);
1675 disp = *(char *)codep++;
1682 disp = (short)get16 ();
1683 /* for some reason, a data16 prefix on a jump instruction
1684 means that the pc is masked to 16 bits after the
1685 displacement is added! */
1690 oappend ("<internal disassembler error>");
1693 disp = (start_pc + codep - start_codep + disp) & mask;
1695 sprintf (scratchbuf, "0x%x", disp);
1696 oappend (scratchbuf);
1702 static char *sreg[] = {
1703 "%es","%cs","%ss","%ds","%fs","%gs","%?","%?",
1706 oappend (sreg[reg]);
1726 sprintf (scratchbuf, "0x%x,0x%x", seg, offset);
1727 oappend (scratchbuf);
1733 offset = (short)get16 ();
1735 offset = start_pc + codep - start_codep + offset;
1737 sprintf (scratchbuf, "0x%x", offset);
1738 oappend (scratchbuf);
1741 oappend ("<internal disassembler error>");
1756 sprintf (scratchbuf, "0x%x", off);
1757 oappend (scratchbuf);
1764 oappend (aflag ? "%edi" : "%di");
1772 oappend (aflag ? "%esi" : "%si");
1785 codep++; /* skip mod/rm */
1786 sprintf (scratchbuf, "%%cr%d", reg);
1787 oappend (scratchbuf);
1793 codep++; /* skip mod/rm */
1794 sprintf (scratchbuf, "%%db%d", reg);
1795 oappend (scratchbuf);
1801 codep++; /* skip mod/rm */
1802 sprintf (scratchbuf, "%%tr%d", reg);
1803 oappend (scratchbuf);
1811 oappend (names32[rm]);
1814 oappend (names16[rm]);
1820 print_insn (memaddr, stream)
1824 unsigned char buffer[MAXLEN];
1826 read_memory (memaddr, buffer, MAXLEN);
1828 return (i386dis ((int)memaddr, buffer, stream));