ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /libinterp/das-arm.c/
#include <lib9.h> typedef struct Instr Instr; struct Instr { ulong w; ulong addr; uchar op; /* super opcode */ uchar cond; /* bits 28-31 */ uchar store; /* bit 20 */ uchar rd; /* bits 12-15 */ uchar rn; /* bits 16-19 */ uchar rs; /* bits 0-11 */ long imm; /* rotated imm */ char* curr; /* fill point in buffer */ char* end; /* end of buffer */ char* err; /* error message */ }; typedef struct Opcode Opcode; struct Opcode { char* o; void (*f)(Opcode*, Instr*); char* a; }; static void format(char*, Instr*, char*); static int arminst(ulong, char, char*, int); static int armdas(ulong, char*, int); static char* cond[16] = { "EQ", "NE", "CS", "CC", "MI", "PL", "VS", "VC", "HI", "LS", "GE", "LT", "GT", "LE", 0, "NV" }; static char* shtype[4] = { "<<", ">>", "->", "@>" }; static int get4(ulong addr, long *v) { *v = *(ulong*)addr; return 1; } static char * _hexify(char *buf, ulong p, int zeros) { ulong d; d = p/16; if(d) buf = _hexify(buf, d, zeros-1); else while(zeros--) *buf++ = '0'; *buf++ = "0123456789abcdef"[p&0x0f]; return buf; } int armclass(long w) { int op; op = (w >> 25) & 0x7; switch(op) { case 0: /* data processing r,r,r */ op = ((w >> 4) & 0xf); if(op == 0x9) { op = 48+16; /* mul */ if(w & (1<<24)) { op += 2; if(w & (1<<22)) op++; /* swap */ break; } if(w & (1<<21)) op++; /* mla */ break; } op = (w >> 21) & 0xf; if(w & (1<<4)) op += 32; else if(w & (31<<7)) op += 16; break; case 1: /* data processing i,r,r */ op = (48) + ((w >> 21) & 0xf); break; case 2: /* load/store byte/word i(r) */ op = (48+20) + ((w >> 22) & 0x1) + ((w >> 19) & 0x2); break; case 3: /* load/store byte/word (r)(r) */ op = (48+20+4) + ((w >> 22) & 0x1) + ((w >> 19) & 0x2); break; case 4: /* block data transfer (r)(r) */ op = (48+20+4+4) + ((w >> 20) & 0x1); break; case 5: /* branch / branch link */ op = (48+20+4+4+2) + ((w >> 24) & 0x1); break; case 7: /* coprocessor crap */ op = (48+20+4+4+2+2) + ((w >> 3) & 0x2) + ((w >> 20) & 0x1); break; default: op = (48+20+4+4+2+2+4); break; } return op; } static int decode(ulong pc, Instr *i) { long w; get4(pc, &w); i->w = w; i->addr = pc; i->cond = (w >> 28) & 0xF; i->op = armclass(w); return 1; } static void bprint(Instr *i, char *fmt, ...) { va_list arg; va_start(arg, fmt); i->curr = vseprint(i->curr, i->end, fmt, arg); va_end(arg); } static void armdps(Opcode *o, Instr *i) { i->store = (i->w >> 20) & 1; i->rn = (i->w >> 16) & 0xf; i->rd = (i->w >> 12) & 0xf; i->rs = (i->w >> 0) & 0xf; if(i->rn == 15 && i->rs == 0) { if(i->op == 8) { format("MOVW", i,"CPSR, R%d"); return; } else if(i->op == 10) { format("MOVW", i,"SPSR, R%d"); return; } } else if(i->rn == 9 && i->rd == 15) { if(i->op == 9) { format("MOVW", i, "R%s, CPSR"); return; } else if(i->op == 11) { format("MOVW", i, "R%s, SPSR"); return; } } format(o->o, i, o->a); } static void armdpi(Opcode *o, Instr *i) { ulong v; int c; v = (i->w >> 0) & 0xff; c = (i->w >> 8) & 0xf; while(c) { v = (v<<30) | (v>>2); c--; } i->imm = v; i->store = (i->w >> 20) & 1; i->rn = (i->w >> 16) & 0xf; i->rd = (i->w >> 12) & 0xf; i->rs = i->w&0x0f; /* RET is encoded as ADD #0,R14,R15 */ if(i->w == 0xe282f000){ format("RET", i, ""); return; } else format(o->o, i, o->a); } static void armsdti(Opcode *o, Instr *i) { ulong v; v = (i->w >> 0) & 0xfff; if(!(i->w & (1<<23))) v = -v; i->store = ((i->w >> 23) & 0x2) | ((i->w >>21) & 0x1); i->imm = v; i->rn = (i->w >> 16) & 0xf; i->rd = (i->w >> 12) & 0xf; /* convert load of offset(PC) to a load immediate */ if(i->rn == 15 && (i->w & (1<<20)) && get4(i->addr+v+8, &i->imm) > 0) format(o->o, i, "$#%i,R%d"); else format(o->o, i, o->a); } static void armsdts(Opcode *o, Instr *i) { i->store = ((i->w >> 23) & 0x2) | ((i->w >>21) & 0x1); i->rs = (i->w >> 0) & 0xf; i->rn = (i->w >> 16) & 0xf; i->rd = (i->w >> 12) & 0xf; format(o->o, i, o->a); } static void armbdt(Opcode *o, Instr *i) { i->store = (i->w >> 21) & 0x3; /* S & W bits */ i->rn = (i->w >> 16) & 0xf; i->imm = i->w & 0xffff; if(i->w == 0xe8fd8000) format("RFE", i, ""); else format(o->o, i, o->a); } static void armund(Opcode *o, Instr *i) { format(o->o, i, o->a); } static void armcdt(Opcode *o, Instr *i) { format(o->o, i, o->a); } static void armunk(Opcode *o, Instr *i) { format(o->o, i, o->a); } static void armb(Opcode *o, Instr *i) { ulong v; v = i->w & 0xffffff; if(v & 0x800000) v |= ~0xffffff; i->imm = (v<<2) + i->addr + 8; format(o->o, i, o->a); } static void armco(Opcode *o, Instr *i) /* coprocessor instructions */ { int op, p, cp; char buf[1024]; i->rn = (i->w >> 16) & 0xf; i->rd = (i->w >> 12) & 0xf; i->rs = i->w&0xf; cp = (i->w >> 8) & 0xf; p = (i->w >> 5) & 0x7; if(i->w&0x10) { op = (i->w >> 20) & 0x0f; snprint(buf, sizeof(buf), "#%x, #%x, R%d, C(%d), C(%d), #%x\n", cp, op, i->rd, i->rn, i->rs, p); } else { op = (i->w >> 21) & 0x07; snprint(buf, sizeof(buf), "#%x, #%x, C(%d), C(%d), C(%d), #%x\n", cp, op, i->rd, i->rn, i->rs, p); } format(o->o, i, buf); } static Opcode opcodes[] = { "AND%C%S", armdps, "R%s,R%n,R%d", "EOR%C%S", armdps, "R%s,R%n,R%d", "SUB%C%S", armdps, "R%s,R%n,R%d", "RSB%C%S", armdps, "R%s,R%n,R%d", "ADD%C%S", armdps, "R%s,R%n,R%d", "ADC%C%S", armdps, "R%s,R%n,R%d", "SBC%C%S", armdps, "R%s,R%n,R%d", "RSC%C%S", armdps, "R%s,R%n,R%d", "TST%C%S", armdps, "R%s,R%n,", "TEQ%C%S", armdps, "R%s,R%n,", "CMP%C%S", armdps, "R%s,R%n,", "CMN%C%S", armdps, "R%s,R%n,", "ORR%C%S", armdps, "R%s,R%n,R%d", "MOVW%C%S", armdps, "R%s,R%d", "BIC%C%S", armdps, "R%s,R%n,R%d", "MVN%C%S", armdps, "R%s,R%d", "AND%C%S", armdps, "(R%s%h#%m),R%n,R%d", "EOR%C%S", armdps, "(R%s%h#%m),R%n,R%d", "SUB%C%S", armdps, "(R%s%h#%m),R%n,R%d", "RSB%C%S", armdps, "(R%s%h#%m),R%n,R%d", "ADD%C%S", armdps, "(R%s%h#%m),R%n,R%d", "ADC%C%S", armdps, "(R%s%h#%m),R%n,R%d", "SBC%C%S", armdps, "(R%s%h#%m),R%n,R%d", "RSC%C%S", armdps, "(R%s%h#%m),R%n,R%d", "TST%C%S", armdps, "(R%s%h#%m),R%n,", "TEQ%C%S", armdps, "(R%s%h#%m),R%n,", "CMP%C%S", armdps, "(R%s%h#%m),R%n,", "CMN%C%S", armdps, "(R%s%h#%m),R%n,", "ORR%C%S", armdps, "(R%s%h#%m),R%n,R%d", "MOVW%C%S", armdps, "(R%s%h#%m),R%d", "BIC%C%S", armdps, "(R%s%h#%m),R%n,R%d", "MVN%C%S", armdps, "(R%s%h#%m),R%d", "AND%C%S", armdps, "(R%s%hR%m),R%n,R%d", "EOR%C%S", armdps, "(R%s%hR%m),R%n,R%d", "SUB%C%S", armdps, "(R%s%hR%m),R%n,R%d", "RSB%C%S", armdps, "(R%s%hR%m),R%n,R%d", "ADD%C%S", armdps, "(R%s%hR%m),R%n,R%d", "ADC%C%S", armdps, "(R%s%hR%m),R%n,R%d", "SBC%C%S", armdps, "(R%s%hR%m),R%n,R%d", "RSC%C%S", armdps, "(R%s%hR%m),R%n,R%d", "TST%C%S", armdps, "(R%s%hR%m),R%n,", "TEQ%C%S", armdps, "(R%s%hR%m),R%n,", "CMP%C%S", armdps, "(R%s%hR%m),R%n,", "CMN%C%S", armdps, "(R%s%hR%m),R%n,", "ORR%C%S", armdps, "(R%s%hR%m),R%n,R%d", "MOVW%C%S", armdps, "(R%s%hR%m),R%d", "BIC%C%S", armdps, "(R%s%hR%m),R%n,R%d", "MVN%C%S", armdps, "(R%s%hR%m),R%d", "AND%C%S", armdpi, "$#%i,R%n,R%d", "EOR%C%S", armdpi, "$#%i,R%n,R%d", "SUB%C%S", armdpi, "$#%i,R%n,R%d", "RSB%C%S", armdpi, "$#%i,R%n,R%d", "ADD%C%S", armdpi, "$#%i,R%n,R%d", "ADC%C%S", armdpi, "$#%i,R%n,R%d", "SBC%C%S", armdpi, "$#%i,R%n,R%d", "RSC%C%S", armdpi, "$#%i,R%n,R%d", "TST%C%S", armdpi, "$#%i,R%n,", "TEQ%C%S", armdpi, "$#%i,R%n,", "CMP%C%S", armdpi, "$#%i,R%n,", "CMN%C%S", armdpi, "$#%i,R%n,", "ORR%C%S", armdpi, "$#%i,R%n,R%d", "MOVW%C%S", armdpi, "$#%i,,R%d", "BIC%C%S", armdpi, "$#%i,R%n,R%d", "MVN%C%S", armdpi, "$#%i,,R%d", "MUL%C%S", armdpi, "R%s,R%m,R%n", "MULA%C%S", armdpi, "R%s,R%m,R%n,R%d", "SWPW", armdpi, "R%s,(R%n),R%d", "SWPB", armdpi, "R%s,(R%n),R%d", "MOVW%C%p", armsdti,"R%d,#%i(R%n)", "MOVB%C%p", armsdti,"R%d,#%i(R%n)", "MOVW%C%p", armsdti,"#%i(R%n),R%d", "MOVB%C%p", armsdti,"#%i(R%n),R%d", "MOVW%C%p", armsdts,"R%d,%D(R%s%h#%m)(R%n)", "MOVB%C%p", armsdts,"R%d,%D(R%s%h#%m)(R%n)", "MOVW%C%p", armsdts,"%D(R%s%h#%m)(R%n),R%d", "MOVB%C%p", armsdts,"%D(R%s%h#%m)(R%n),R%d", "MOVM%C%P%a", armbdt, "R%n,[%r]", "MOVM%C%P%a", armbdt, "[%r],R%n", "B%C", armb, "%b", "BL%C", armb, "%b", "CDP%C", armco, "", "CDP%C", armco, "", "MCR%C", armco, "", "MRC%C", armco, "", "UNK", armunk, "", }; static char *mode[] = { 0, "IA", "DB", "IB" }; static char *pw[] = { "P", "PW", 0, "W" }; static char *sw[] = { 0, "W", "S", "SW" }; static void format(char *mnemonic, Instr *i, char *f) { int j, k, m, n; if(mnemonic) format(0, i, mnemonic); if(f == 0) return; if(mnemonic) if(i->curr < i->end) *i->curr++ = '\t'; for ( ; *f && i->curr < i->end; f++) { if(*f != '%') { *i->curr++ = *f; continue; } switch (*++f) { case 'C': /* .CONDITION */ if(cond[i->cond]) bprint(i, ".%s", cond[i->cond]); break; case 'S': /* .STORE */ if(i->store) bprint(i, ".S"); break; case 'P': /* P & U bits for block move */ n = (i->w >>23) & 0x3; if (mode[n]) bprint(i, ".%s", mode[n]); break; case 'D': /* ~U bit for single data xfer */ if((i->w & (1<<23)) == 0) bprint(i, "-"); break; case 'p': /* P & W bits for single data xfer*/ if (pw[i->store]) bprint(i, ".%s", pw[i->store]); break; case 'a': /* S & W bits for single data xfer*/ if (sw[i->store]) bprint(i, ".%s", sw[i->store]); break; case 's': bprint(i, "%d", i->rs & 0xf); break; case 'm': bprint(i, "%d", (i->w>>7) & 0x1f); break; case 'h': bprint(i, "%s", shtype[(i->w>>5) & 0x3]); break; case 'n': bprint(i, "%d", i->rn); break; case 'd': bprint(i, "%d", i->rd); break; case 'i': bprint(i, "%lux", i->imm); break; case 'b': bprint(i, "%lux", i->imm); break; case 'r': n = i->imm&0xffff; j = 0; k = 0; while(n) { m = j; while(n&0x1) { j++; n >>= 1; } if(j != m) { if(k) bprint(i, ","); if(j == m+1) bprint(i, "R%d", m); else bprint(i, "R%d-R%d", m, j-1); k = 1; } j++; n >>= 1; } break; case '\0': *i->curr++ = '%'; return; default: bprint(i, "%%%c", *f); break; } } *i->curr = 0; } void das(ulong *x, int n) { ulong pc; Instr i; char buf[128]; pc = (ulong)x; while(n > 0) { i.curr = buf; i.end = buf+sizeof(buf)-1; if(decode(pc, &i) < 0) sprint(buf, "???"); else (*opcodes[i.op].f)(&opcodes[i.op], &i); print("%.8lux %.8lux\t%s\n", pc, i.w, buf); pc += 4; n--; } }