1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252 |
- /* $Id$ */
- #include <common.h>
- #include <linux/ctype.h>
- #include <bedbug/bedbug.h>
- #include <bedbug/ppc.h>
- #include <bedbug/regs.h>
- #include <bedbug/tables.h>
- #define Elf32_Word unsigned long
- /* USE_SOURCE_CODE enables some symbolic debugging functions of this
- code. This is only useful if the program will have access to the
- source code for the binary being examined.
- */
- /* #define USE_SOURCE_CODE 1 */
- #ifdef USE_SOURCE_CODE
- extern int line_info_from_addr __P ((Elf32_Word, char *, char *, int *));
- extern struct symreflist *symByAddr;
- extern char *symbol_name_from_addr __P ((Elf32_Word, int, int *));
- #endif /* USE_SOURCE_CODE */
- int print_operands __P ((struct ppc_ctx *));
- int get_operand_value __P ((struct opcode *, unsigned long,
- enum OP_FIELD, unsigned long *));
- struct opcode *find_opcode __P ((unsigned long));
- struct opcode *find_opcode_by_name __P ((char *));
- char *spr_name __P ((int));
- int spr_value __P ((char *));
- char *tbr_name __P ((int));
- int tbr_value __P ((char *));
- int parse_operand __P ((unsigned long, struct opcode *,
- struct operand *, char *, int *));
- int get_word __P ((char **, char *));
- long read_number __P ((char *));
- int downstring __P ((char *));
- /*======================================================================
- * Entry point for the PPC disassembler.
- *
- * Arguments:
- * memaddr The address to start disassembling from.
- *
- * virtual If this value is non-zero, then this will be
- * used as the base address for the output and
- * symbol lookups. If this value is zero then
- * memaddr is used as the absolute address.
- *
- * num_instr The number of instructions to disassemble. Since
- * each instruction is 32 bits long, this can be
- * computed if you know the total size of the region.
- *
- * pfunc The address of a function that is called to print
- * each line of output. The function should take a
- * single character pointer as its parameters a la puts.
- *
- * flags Sets options for the output. This is a
- * bitwise-inclusive-OR of the following
- * values. Note that only one of the radix
- * options may be set.
- *
- * F_RADOCTAL - output radix is unsigned base 8.
- * F_RADUDECIMAL - output radix is unsigned base 10.
- * F_RADSDECIMAL - output radix is signed base 10.
- * F_RADHEX - output radix is unsigned base 16.
- * F_SIMPLE - use simplified mnemonics.
- * F_SYMBOL - lookup symbols for addresses.
- * F_INSTR - output raw instruction.
- * F_LINENO - show line # info if available.
- *
- * Returns TRUE if the area was successfully disassembled or FALSE if
- * a problem was encountered with accessing the memory.
- */
- int disppc (unsigned char *memaddr, unsigned char *virtual, int num_instr,
- int (*pfunc) (const char *), unsigned long flags)
- {
- int i;
- struct ppc_ctx ctx;
- #ifdef USE_SOURCE_CODE
- int line_no = 0;
- int last_line_no = 0;
- char funcname[128] = { 0 };
- char filename[256] = { 0 };
- char last_funcname[128] = { 0 };
- int symoffset;
- char *symname;
- char *cursym = (char *) 0;
- #endif /* USE_SOURCE_CODE */
- /*------------------------------------------------------------*/
- ctx.flags = flags;
- ctx.virtual = virtual;
- /* Figure out the output radix before we go any further */
- if (ctx.flags & F_RADOCTAL) {
- /* Unsigned octal output */
- strcpy (ctx.radix_fmt, "O%o");
- } else if (ctx.flags & F_RADUDECIMAL) {
- /* Unsigned decimal output */
- strcpy (ctx.radix_fmt, "%u");
- } else if (ctx.flags & F_RADSDECIMAL) {
- /* Signed decimal output */
- strcpy (ctx.radix_fmt, "%d");
- } else {
- /* Unsigned hex output */
- strcpy (ctx.radix_fmt, "0x%x");
- }
- if (ctx.virtual == 0) {
- ctx.virtual = memaddr;
- }
- #ifdef USE_SOURCE_CODE
- if (ctx.flags & F_SYMBOL) {
- if (symByAddr == 0) /* no symbols loaded */
- ctx.flags &= ~F_SYMBOL;
- else {
- cursym = (char *) 0;
- symoffset = 0;
- }
- }
- #endif /* USE_SOURCE_CODE */
- /* format each line as "XXXXXXXX: <symbol> IIIIIIII disassembly" where,
- XXXXXXXX is the memory address in hex,
- <symbol> is the symbolic location if F_SYMBOL is set.
- IIIIIIII is the raw machine code in hex if F_INSTR is set,
- and disassembly is the disassembled machine code with numbers
- formatted according to the 'radix' parameter */
- for (i = 0; i < num_instr; ++i, memaddr += 4, ctx.virtual += 4) {
- #ifdef USE_SOURCE_CODE
- if (ctx.flags & F_LINENO) {
- if ((line_info_from_addr ((Elf32_Word) ctx.virtual, filename,
- funcname, &line_no) == TRUE) &&
- ((line_no != last_line_no) ||
- (strcmp (last_funcname, funcname) != 0))) {
- print_source_line (filename, funcname, line_no, pfunc);
- }
- last_line_no = line_no;
- strcpy (last_funcname, funcname);
- }
- #endif /* USE_SOURCE_CODE */
- sprintf (ctx.data, "%08lx: ", (unsigned long) ctx.virtual);
- ctx.datalen = 10;
- #ifdef USE_SOURCE_CODE
- if (ctx.flags & F_SYMBOL) {
- if ((symname =
- symbol_name_from_addr ((Elf32_Word) ctx.virtual,
- TRUE, 0)) != 0) {
- cursym = symname;
- symoffset = 0;
- } else {
- if ((cursym == 0) &&
- ((symname =
- symbol_name_from_addr ((Elf32_Word) ctx.virtual,
- FALSE, &symoffset)) != 0)) {
- cursym = symname;
- } else {
- symoffset += 4;
- }
- }
- if (cursym != 0) {
- sprintf (&ctx.data[ctx.datalen], "<%s+", cursym);
- ctx.datalen = strlen (ctx.data);
- sprintf (&ctx.data[ctx.datalen], ctx.radix_fmt, symoffset);
- strcat (ctx.data, ">");
- ctx.datalen = strlen (ctx.data);
- }
- }
- #endif /* USE_SOURCE_CODE */
- ctx.instr = INSTRUCTION (memaddr);
- if (ctx.flags & F_INSTR) {
- /* Find the opcode structure for this opcode. If one is not found
- then it must be an illegal instruction */
- sprintf (&ctx.data[ctx.datalen],
- " %02lx %02lx %02lx %02lx ",
- ((ctx.instr >> 24) & 0xff),
- ((ctx.instr >> 16) & 0xff), ((ctx.instr >> 8) & 0xff),
- (ctx.instr & 0xff));
- ctx.datalen += 18;
- } else {
- strcat (ctx.data, " ");
- ctx.datalen += 3;
- }
- if ((ctx.op = find_opcode (ctx.instr)) == 0) {
- /* Illegal Opcode */
- sprintf (&ctx.data[ctx.datalen], " .long 0x%08lx",
- ctx.instr);
- ctx.datalen += 24;
- (*pfunc) (ctx.data);
- continue;
- }
- if (((ctx.flags & F_SIMPLE) == 0) ||
- (ctx.op->hfunc == 0) || ((*ctx.op->hfunc) (&ctx) == FALSE)) {
- sprintf (&ctx.data[ctx.datalen], "%-7s ", ctx.op->name);
- ctx.datalen += 8;
- print_operands (&ctx);
- }
- (*pfunc) (ctx.data);
- }
- return TRUE;
- } /* disppc */
- /*======================================================================
- * Called by the disassembler to print the operands for an instruction.
- *
- * Arguments:
- * ctx A pointer to the disassembler context record.
- *
- * always returns 0.
- */
- int print_operands (struct ppc_ctx *ctx)
- {
- int open_parens = 0;
- int field;
- unsigned long operand;
- struct operand *opr;
- #ifdef USE_SOURCE_CODE
- char *symname;
- int offset;
- #endif /* USE_SOURCE_CODE */
- /*------------------------------------------------------------*/
- /* Walk through the operands and list each in order */
- for (field = 0; ctx->op->fields[field] != 0; ++field) {
- if (ctx->op->fields[field] > n_operands) {
- continue; /* bad operand ?! */
- }
- opr = &operands[ctx->op->fields[field] - 1];
- if (opr->hint & OH_SILENT) {
- continue;
- }
- if ((field > 0) && !open_parens) {
- strcat (ctx->data, ",");
- ctx->datalen++;
- }
- operand = (ctx->instr >> opr->shift) & ((1 << opr->bits) - 1);
- if (opr->hint & OH_ADDR) {
- if ((operand & (1 << (opr->bits - 1))) != 0) {
- operand = operand - (1 << opr->bits);
- }
- if (ctx->op->hint & H_RELATIVE)
- operand = (operand << 2) + (unsigned long) ctx->virtual;
- else
- operand = (operand << 2);
- sprintf (&ctx->data[ctx->datalen], "0x%lx", operand);
- ctx->datalen = strlen (ctx->data);
- #ifdef USE_SOURCE_CODE
- if ((ctx->flags & F_SYMBOL) &&
- ((symname =
- symbol_name_from_addr (operand, 0, &offset)) != 0)) {
- sprintf (&ctx->data[ctx->datalen], " <%s", symname);
- if (offset != 0) {
- strcat (ctx->data, "+");
- ctx->datalen = strlen (ctx->data);
- sprintf (&ctx->data[ctx->datalen], ctx->radix_fmt,
- offset);
- }
- strcat (ctx->data, ">");
- }
- #endif /* USE_SOURCE_CODE */
- }
- else if (opr->hint & OH_REG) {
- if ((operand == 0) &&
- (opr->field == O_rA) && (ctx->op->hint & H_RA0_IS_0)) {
- strcat (ctx->data, "0");
- } else {
- sprintf (&ctx->data[ctx->datalen], "r%d", (short) operand);
- }
- if (open_parens) {
- strcat (ctx->data, ")");
- open_parens--;
- }
- }
- else if (opr->hint & OH_SPR) {
- strcat (ctx->data, spr_name (operand));
- }
- else if (opr->hint & OH_TBR) {
- strcat (ctx->data, tbr_name (operand));
- }
- else if (opr->hint & OH_LITERAL) {
- switch (opr->field) {
- case O_cr2:
- strcat (ctx->data, "cr2");
- ctx->datalen += 3;
- break;
- default:
- break;
- }
- }
- else {
- sprintf (&ctx->data[ctx->datalen], ctx->radix_fmt,
- (unsigned short) operand);
- if (open_parens) {
- strcat (ctx->data, ")");
- open_parens--;
- }
- else if (opr->hint & OH_OFFSET) {
- strcat (ctx->data, "(");
- open_parens++;
- }
- }
- ctx->datalen = strlen (ctx->data);
- }
- return 0;
- } /* print_operands */
- /*======================================================================
- * Called to get the value of an arbitrary operand with in an instruction.
- *
- * Arguments:
- * op The pointer to the opcode structure to which
- * the operands belong.
- *
- * instr The instruction (32 bits) containing the opcode
- * and the operands to print. By the time that
- * this routine is called the operand has already
- * been added to the output.
- *
- * field The field (operand) to get the value of.
- *
- * value The address of an unsigned long to be filled in
- * with the value of the operand if it is found. This
- * will only be filled in if the function returns
- * TRUE. This may be passed as 0 if the value is
- * not required.
- *
- * Returns TRUE if the operand was found or FALSE if it was not.
- */
- int get_operand_value (struct opcode *op, unsigned long instr,
- enum OP_FIELD field, unsigned long *value)
- {
- int i;
- struct operand *opr;
- /*------------------------------------------------------------*/
- if (field > n_operands) {
- return FALSE; /* bad operand ?! */
- }
- /* Walk through the operands and list each in order */
- for (i = 0; op->fields[i] != 0; ++i) {
- if (op->fields[i] != field) {
- continue;
- }
- opr = &operands[op->fields[i] - 1];
- if (value) {
- *value = (instr >> opr->shift) & ((1 << opr->bits) - 1);
- }
- return TRUE;
- }
- return FALSE;
- } /* operand_value */
- /*======================================================================
- * Called by the disassembler to match an opcode value to an opcode structure.
- *
- * Arguments:
- * instr The instruction (32 bits) to match. This value
- * may contain operand values as well as the opcode
- * since they will be masked out anyway for this
- * search.
- *
- * Returns the address of an opcode struct (from the opcode table) if the
- * operand successfully matched an entry, or 0 if no match was found.
- */
- struct opcode *find_opcode (unsigned long instr)
- {
- struct opcode *ptr;
- int top = 0;
- int bottom = n_opcodes - 1;
- int idx;
- /*------------------------------------------------------------*/
- while (top <= bottom) {
- idx = (top + bottom) >> 1;
- ptr = &opcodes[idx];
- if ((instr & ptr->mask) < ptr->opcode) {
- bottom = idx - 1;
- } else if ((instr & ptr->mask) > ptr->opcode) {
- top = idx + 1;
- } else {
- return ptr;
- }
- }
- return (struct opcode *) 0;
- } /* find_opcode */
- /*======================================================================
- * Called by the assembler to match an opcode name to an opcode structure.
- *
- * Arguments:
- * name The text name of the opcode, e.g. "b", "mtspr", etc.
- *
- * The opcodes are sorted numerically by their instruction binary code
- * so a search for the name cannot use the binary search used by the
- * other find routine.
- *
- * Returns the address of an opcode struct (from the opcode table) if the
- * name successfully matched an entry, or 0 if no match was found.
- */
- struct opcode *find_opcode_by_name (char *name)
- {
- int idx;
- /*------------------------------------------------------------*/
- downstring (name);
- for (idx = 0; idx < n_opcodes; ++idx) {
- if (!strcmp (name, opcodes[idx].name))
- return &opcodes[idx];
- }
- return (struct opcode *) 0;
- } /* find_opcode_by_name */
- /*======================================================================
- * Convert the 'spr' operand from its numeric value to its symbolic name.
- *
- * Arguments:
- * value The value of the 'spr' operand. This value should
- * be unmodified from its encoding in the instruction.
- * the split-field computations will be performed
- * here before the switch.
- *
- * Returns the address of a character array containing the name of the
- * special purpose register defined by the 'value' parameter, or the
- * address of a character array containing "???" if no match was found.
- */
- char *spr_name (int value)
- {
- unsigned short spr;
- static char other[10];
- int i;
- /*------------------------------------------------------------*/
- /* spr is a 10 bit field whose interpretation has the high and low
- five-bit fields reversed from their encoding in the operand */
- spr = ((value >> 5) & 0x1f) | ((value & 0x1f) << 5);
- for (i = 0; i < n_sprs; ++i) {
- if (spr == spr_map[i].spr_val)
- return spr_map[i].spr_name;
- }
- sprintf (other, "%d", spr);
- return other;
- } /* spr_name */
- /*======================================================================
- * Convert the 'spr' operand from its symbolic name to its numeric value
- *
- * Arguments:
- * name The symbolic name of the 'spr' operand. The
- * split-field encoding will be done by this routine.
- * NOTE: name can be a number.
- *
- * Returns the numeric value for the spr appropriate for encoding a machine
- * instruction. Returns 0 if unable to find the SPR.
- */
- int spr_value (char *name)
- {
- struct spr_info *sprp;
- int spr;
- int i;
- /*------------------------------------------------------------*/
- if (!name || !*name)
- return 0;
- if (isdigit ((int) name[0])) {
- i = htonl (read_number (name));
- spr = ((i >> 5) & 0x1f) | ((i & 0x1f) << 5);
- return spr;
- }
- downstring (name);
- for (i = 0; i < n_sprs; ++i) {
- sprp = &spr_map[i];
- if (strcmp (name, sprp->spr_name) == 0) {
- /* spr is a 10 bit field whose interpretation has the high and low
- five-bit fields reversed from their encoding in the operand */
- i = htonl (sprp->spr_val);
- spr = ((i >> 5) & 0x1f) | ((i & 0x1f) << 5);
- return spr;
- }
- }
- return 0;
- } /* spr_value */
- /*======================================================================
- * Convert the 'tbr' operand from its numeric value to its symbolic name.
- *
- * Arguments:
- * value The value of the 'tbr' operand. This value should
- * be unmodified from its encoding in the instruction.
- * the split-field computations will be performed
- * here before the switch.
- *
- * Returns the address of a character array containing the name of the
- * time base register defined by the 'value' parameter, or the address
- * of a character array containing "???" if no match was found.
- */
- char *tbr_name (int value)
- {
- unsigned short tbr;
- /*------------------------------------------------------------*/
- /* tbr is a 10 bit field whose interpretation has the high and low
- five-bit fields reversed from their encoding in the operand */
- tbr = ((value >> 5) & 0x1f) | ((value & 0x1f) << 5);
- if (tbr == 268)
- return "TBL";
- else if (tbr == 269)
- return "TBU";
- return "???";
- } /* tbr_name */
- /*======================================================================
- * Convert the 'tbr' operand from its symbolic name to its numeric value.
- *
- * Arguments:
- * name The symbolic name of the 'tbr' operand. The
- * split-field encoding will be done by this routine.
- *
- * Returns the numeric value for the spr appropriate for encoding a machine
- * instruction. Returns 0 if unable to find the TBR.
- */
- int tbr_value (char *name)
- {
- int tbr;
- int val;
- /*------------------------------------------------------------*/
- if (!name || !*name)
- return 0;
- downstring (name);
- if (isdigit ((int) name[0])) {
- val = read_number (name);
- if (val != 268 && val != 269)
- return 0;
- } else if (strcmp (name, "tbl") == 0)
- val = 268;
- else if (strcmp (name, "tbu") == 0)
- val = 269;
- else
- return 0;
- /* tbr is a 10 bit field whose interpretation has the high and low
- five-bit fields reversed from their encoding in the operand */
- val = htonl (val);
- tbr = ((val >> 5) & 0x1f) | ((val & 0x1f) << 5);
- return tbr;
- } /* tbr_name */
- /*======================================================================
- * The next several functions (handle_xxx) are the routines that handle
- * disassembling the opcodes with simplified mnemonics.
- *
- * Arguments:
- * ctx A pointer to the disassembler context record.
- *
- * Returns TRUE if the simpler form was printed or FALSE if it was not.
- */
- int handle_bc (struct ppc_ctx *ctx)
- {
- unsigned long bo;
- unsigned long bi;
- static struct opcode blt = { B_OPCODE (16, 0, 0), B_MASK, {O_BD, 0},
- 0, "blt", H_RELATIVE
- };
- static struct opcode bne =
- { B_OPCODE (16, 0, 0), B_MASK, {O_cr2, O_BD, 0},
- 0, "bne", H_RELATIVE
- };
- static struct opcode bdnz = { B_OPCODE (16, 0, 0), B_MASK, {O_BD, 0},
- 0, "bdnz", H_RELATIVE
- };
- /*------------------------------------------------------------*/
- if (get_operand_value (ctx->op, ctx->instr, O_BO, &bo) == FALSE)
- return FALSE;
- if (get_operand_value (ctx->op, ctx->instr, O_BI, &bi) == FALSE)
- return FALSE;
- if ((bo == 12) && (bi == 0)) {
- ctx->op = &blt;
- sprintf (&ctx->data[ctx->datalen], "%-7s ", ctx->op->name);
- ctx->datalen += 8;
- print_operands (ctx);
- return TRUE;
- } else if ((bo == 4) && (bi == 10)) {
- ctx->op = =⃥
- sprintf (&ctx->data[ctx->datalen], "%-7s ", ctx->op->name);
- ctx->datalen += 8;
- print_operands (ctx);
- return TRUE;
- } else if ((bo == 16) && (bi == 0)) {
- ctx->op = &bdnz;
- sprintf (&ctx->data[ctx->datalen], "%-7s ", ctx->op->name);
- ctx->datalen += 8;
- print_operands (ctx);
- return TRUE;
- }
- return FALSE;
- } /* handle_blt */
- /*======================================================================
- * Outputs source line information for the disassembler. This should
- * be modified in the future to lookup the actual line of source code
- * from the file, but for now this will do.
- *
- * Arguments:
- * filename The address of a character array containing the
- * absolute path and file name of the source file.
- *
- * funcname The address of a character array containing the
- * name of the function (not C++ demangled (yet))
- * to which this code belongs.
- *
- * line_no An integer specifying the source line number that
- * generated this code.
- *
- * pfunc The address of a function to call to print the output.
- *
- *
- * Returns TRUE if it was able to output the line info, or false if it was
- * not.
- */
- int print_source_line (char *filename, char *funcname,
- int line_no, int (*pfunc) (const char *))
- {
- char out_buf[256];
- /*------------------------------------------------------------*/
- (*pfunc) (""); /* output a newline */
- sprintf (out_buf, "%s %s(): line %d", filename, funcname, line_no);
- (*pfunc) (out_buf);
- return TRUE;
- } /* print_source_line */
- /*======================================================================
- * Entry point for the PPC assembler.
- *
- * Arguments:
- * asm_buf An array of characters containing the assembly opcode
- * and operands to convert to a POWERPC machine
- * instruction.
- *
- * Returns the machine instruction or zero.
- */
- unsigned long asmppc (unsigned long memaddr, char *asm_buf, int *err)
- {
- struct opcode *opc;
- struct operand *oper[MAX_OPERANDS];
- unsigned long instr;
- unsigned long param;
- char *ptr = asm_buf;
- char scratch[20];
- int i;
- int w_operands = 0; /* wanted # of operands */
- int n_operands = 0; /* # of operands read */
- int asm_debug = 0;
- /*------------------------------------------------------------*/
- if (err)
- *err = 0;
- if (get_word (&ptr, scratch) == 0)
- return 0;
- /* Lookup the opcode structure based on the opcode name */
- if ((opc = find_opcode_by_name (scratch)) == (struct opcode *) 0) {
- if (err)
- *err = E_ASM_BAD_OPCODE;
- return 0;
- }
- if (asm_debug) {
- printf ("asmppc: Opcode = \"%s\"\n", opc->name);
- }
- for (i = 0; i < 8; ++i) {
- if (opc->fields[i] == 0)
- break;
- ++w_operands;
- }
- if (asm_debug) {
- printf ("asmppc: Expecting %d operands\n", w_operands);
- }
- instr = opc->opcode;
- /* read each operand */
- while (n_operands < w_operands) {
- oper[n_operands] = &operands[opc->fields[n_operands] - 1];
- if (oper[n_operands]->hint & OH_SILENT) {
- /* Skip silent operands, they are covered in opc->opcode */
- if (asm_debug) {
- printf ("asmppc: Operand %d \"%s\" SILENT\n", n_operands,
- oper[n_operands]->name);
- }
- ++n_operands;
- continue;
- }
- if (get_word (&ptr, scratch) == 0)
- break;
- if (asm_debug) {
- printf ("asmppc: Operand %d \"%s\" : \"%s\"\n", n_operands,
- oper[n_operands]->name, scratch);
- }
- if ((param = parse_operand (memaddr, opc, oper[n_operands],
- scratch, err)) == -1)
- return 0;
- instr |= param;
- ++n_operands;
- }
- if (n_operands < w_operands) {
- if (err)
- *err = E_ASM_NUM_OPERANDS;
- return 0;
- }
- if (asm_debug) {
- printf ("asmppc: Instruction = 0x%08lx\n", instr);
- }
- return instr;
- } /* asmppc */
- /*======================================================================
- * Called by the assembler to interpret a single operand
- *
- * Arguments:
- * ctx A pointer to the disassembler context record.
- *
- * Returns 0 if the operand is ok, or -1 if it is bad.
- */
- int parse_operand (unsigned long memaddr, struct opcode *opc,
- struct operand *oper, char *txt, int *err)
- {
- long data;
- long mask;
- int is_neg = 0;
- /*------------------------------------------------------------*/
- mask = (1 << oper->bits) - 1;
- if (oper->hint & OH_ADDR) {
- data = read_number (txt);
- if (opc->hint & H_RELATIVE)
- data = data - memaddr;
- if (data < 0)
- is_neg = 1;
- data >>= 2;
- data &= (mask >> 1);
- if (is_neg)
- data |= 1 << (oper->bits - 1);
- }
- else if (oper->hint & OH_REG) {
- if (txt[0] == 'r' || txt[0] == 'R')
- txt++;
- else if (txt[0] == '%' && (txt[1] == 'r' || txt[1] == 'R'))
- txt += 2;
- data = read_number (txt);
- if (data > 31) {
- if (err)
- *err = E_ASM_BAD_REGISTER;
- return -1;
- }
- data = htonl (data);
- }
- else if (oper->hint & OH_SPR) {
- if ((data = spr_value (txt)) == 0) {
- if (err)
- *err = E_ASM_BAD_SPR;
- return -1;
- }
- }
- else if (oper->hint & OH_TBR) {
- if ((data = tbr_value (txt)) == 0) {
- if (err)
- *err = E_ASM_BAD_TBR;
- return -1;
- }
- }
- else {
- data = htonl (read_number (txt));
- }
- return (data & mask) << oper->shift;
- } /* parse_operand */
- char *asm_error_str (int err)
- {
- switch (err) {
- case E_ASM_BAD_OPCODE:
- return "Bad opcode";
- case E_ASM_NUM_OPERANDS:
- return "Bad number of operands";
- case E_ASM_BAD_REGISTER:
- return "Bad register number";
- case E_ASM_BAD_SPR:
- return "Bad SPR name or number";
- case E_ASM_BAD_TBR:
- return "Bad TBR name or number";
- }
- return "";
- } /* asm_error_str */
- /*======================================================================
- * Copy a word from one buffer to another, ignores leading white spaces.
- *
- * Arguments:
- * src The address of a character pointer to the
- * source buffer.
- * dest A pointer to a character buffer to write the word
- * into.
- *
- * Returns the number of non-white space characters copied, or zero.
- */
- int get_word (char **src, char *dest)
- {
- char *ptr = *src;
- int nchars = 0;
- /*------------------------------------------------------------*/
- /* Eat white spaces */
- while (*ptr && isblank (*ptr))
- ptr++;
- if (*ptr == 0) {
- *src = ptr;
- return 0;
- }
- /* Find the text of the word */
- while (*ptr && !isblank (*ptr) && (*ptr != ','))
- dest[nchars++] = *ptr++;
- ptr = (*ptr == ',') ? ptr + 1 : ptr;
- dest[nchars] = 0;
- *src = ptr;
- return nchars;
- } /* get_word */
- /*======================================================================
- * Convert a numeric string to a number, be aware of base notations.
- *
- * Arguments:
- * txt The numeric string.
- *
- * Returns the converted numeric value.
- */
- long read_number (char *txt)
- {
- long val;
- int is_neg = 0;
- /*------------------------------------------------------------*/
- if (txt == 0 || *txt == 0)
- return 0;
- if (*txt == '-') {
- is_neg = 1;
- ++txt;
- }
- if (txt[0] == '0' && (txt[1] == 'x' || txt[1] == 'X')) /* hex */
- val = simple_strtoul (&txt[2], NULL, 16);
- else /* decimal */
- val = simple_strtoul (txt, NULL, 10);
- if (is_neg)
- val = -val;
- return val;
- } /* read_number */
- int downstring (char *s)
- {
- if (!s || !*s)
- return 0;
- while (*s) {
- if (isupper (*s))
- *s = tolower (*s);
- s++;
- }
- return 0;
- } /* downstring */
- /*======================================================================
- * Examines the instruction at the current address and determines the
- * next address to be executed. This will take into account branches
- * of different types so that a "step" and "next" operations can be
- * supported.
- *
- * Arguments:
- * nextaddr The address (to be filled in) of the next
- * instruction to execute. This will only be a valid
- * address if TRUE is returned.
- *
- * step_over A flag indicating how to compute addresses for
- * branch statements:
- * TRUE = Step over the branch (next)
- * FALSE = step into the branch (step)
- *
- * Returns TRUE if it was able to compute the address. Returns FALSE if
- * it has a problem reading the current instruction or one of the registers.
- */
- int find_next_address (unsigned char *nextaddr, int step_over,
- struct pt_regs *regs)
- {
- unsigned long pc; /* SRR0 register from PPC */
- unsigned long ctr; /* CTR register from PPC */
- unsigned long cr; /* CR register from PPC */
- unsigned long lr; /* LR register from PPC */
- unsigned long instr; /* instruction at SRR0 */
- unsigned long next; /* computed instruction for 'next' */
- unsigned long step; /* computed instruction for 'step' */
- unsigned long addr = 0; /* target address operand */
- unsigned long aa = 0; /* AA operand */
- unsigned long lk = 0; /* LK operand */
- unsigned long bo = 0; /* BO operand */
- unsigned long bi = 0; /* BI operand */
- struct opcode *op = 0; /* opcode structure for 'instr' */
- int ctr_ok = 0;
- int cond_ok = 0;
- int conditional = 0;
- int branch = 0;
- /*------------------------------------------------------------*/
- if (nextaddr == 0 || regs == 0) {
- printf ("find_next_address: bad args");
- return FALSE;
- }
- pc = regs->nip & 0xfffffffc;
- instr = INSTRUCTION (pc);
- if ((op = find_opcode (instr)) == (struct opcode *) 0) {
- printf ("find_next_address: can't parse opcode 0x%lx", instr);
- return FALSE;
- }
- ctr = regs->ctr;
- cr = regs->ccr;
- lr = regs->link;
- switch (op->opcode) {
- case B_OPCODE (16, 0, 0): /* bc */
- case B_OPCODE (16, 0, 1): /* bcl */
- case B_OPCODE (16, 1, 0): /* bca */
- case B_OPCODE (16, 1, 1): /* bcla */
- if (!get_operand_value (op, instr, O_BD, &addr) ||
- !get_operand_value (op, instr, O_BO, &bo) ||
- !get_operand_value (op, instr, O_BI, &bi) ||
- !get_operand_value (op, instr, O_AA, &aa) ||
- !get_operand_value (op, instr, O_LK, &lk))
- return FALSE;
- if ((addr & (1 << 13)) != 0)
- addr = addr - (1 << 14);
- addr <<= 2;
- conditional = 1;
- branch = 1;
- break;
- case I_OPCODE (18, 0, 0): /* b */
- case I_OPCODE (18, 0, 1): /* bl */
- case I_OPCODE (18, 1, 0): /* ba */
- case I_OPCODE (18, 1, 1): /* bla */
- if (!get_operand_value (op, instr, O_LI, &addr) ||
- !get_operand_value (op, instr, O_AA, &aa) ||
- !get_operand_value (op, instr, O_LK, &lk))
- return FALSE;
- if ((addr & (1 << 23)) != 0)
- addr = addr - (1 << 24);
- addr <<= 2;
- conditional = 0;
- branch = 1;
- break;
- case XL_OPCODE (19, 528, 0): /* bcctr */
- case XL_OPCODE (19, 528, 1): /* bcctrl */
- if (!get_operand_value (op, instr, O_BO, &bo) ||
- !get_operand_value (op, instr, O_BI, &bi) ||
- !get_operand_value (op, instr, O_LK, &lk))
- return FALSE;
- addr = ctr;
- aa = 1;
- conditional = 1;
- branch = 1;
- break;
- case XL_OPCODE (19, 16, 0): /* bclr */
- case XL_OPCODE (19, 16, 1): /* bclrl */
- if (!get_operand_value (op, instr, O_BO, &bo) ||
- !get_operand_value (op, instr, O_BI, &bi) ||
- !get_operand_value (op, instr, O_LK, &lk))
- return FALSE;
- addr = lr;
- aa = 1;
- conditional = 1;
- branch = 1;
- break;
- default:
- conditional = 0;
- branch = 0;
- break;
- }
- if (conditional) {
- switch ((bo & 0x1e) >> 1) {
- case 0: /* 0000y */
- if (--ctr != 0)
- ctr_ok = 1;
- cond_ok = !(cr & (1 << (31 - bi)));
- break;
- case 1: /* 0001y */
- if (--ctr == 0)
- ctr_ok = 1;
- cond_ok = !(cr & (1 << (31 - bi)));
- break;
- case 2: /* 001zy */
- ctr_ok = 1;
- cond_ok = !(cr & (1 << (31 - bi)));
- break;
- case 4: /* 0100y */
- if (--ctr != 0)
- ctr_ok = 1;
- cond_ok = cr & (1 << (31 - bi));
- break;
- case 5: /* 0101y */
- if (--ctr == 0)
- ctr_ok = 1;
- cond_ok = cr & (1 << (31 - bi));
- break;
- case 6: /* 011zy */
- ctr_ok = 1;
- cond_ok = cr & (1 << (31 - bi));
- break;
- case 8: /* 1z00y */
- if (--ctr != 0)
- ctr_ok = cond_ok = 1;
- break;
- case 9: /* 1z01y */
- if (--ctr == 0)
- ctr_ok = cond_ok = 1;
- break;
- case 10: /* 1z1zz */
- ctr_ok = cond_ok = 1;
- break;
- }
- }
- if (branch && (!conditional || (ctr_ok && cond_ok))) {
- if (aa)
- step = addr;
- else
- step = addr + pc;
- if (lk)
- next = pc + 4;
- else
- next = step;
- } else {
- step = next = pc + 4;
- }
- if (step_over == TRUE)
- *(unsigned long *) nextaddr = next;
- else
- *(unsigned long *) nextaddr = step;
- return TRUE;
- } /* find_next_address */
- /*
- * Copyright (c) 2000 William L. Pitts and W. Gerald Hicks
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms are freely
- * permitted provided that the above copyright notice and this
- * paragraph and the following disclaimer are duplicated in all
- * such forms.
- *
- * This software is provided "AS IS" and without any express or
- * implied warranties, including, without limitation, the implied
- * warranties of merchantability and fitness for a particular
- * purpose.
- */
|