| /* Print VAX instructions. |
| Copyright (C) 1995-2024 Free Software Foundation, Inc. |
| Contributed by Pauline Middelink <middelin@polyware.iaf.nl> |
| |
| This file is part of the GNU opcodes library. |
| |
| This library is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3, or (at your option) |
| any later version. |
| |
| It is distributed in the hope that it will be useful, but WITHOUT |
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public |
| License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| MA 02110-1301, USA. */ |
| |
| #include "sysdep.h" |
| #include <setjmp.h> |
| #include <string.h> |
| #include "opcode/vax.h" |
| #include "disassemble.h" |
| |
| static char *reg_names[] = |
| { |
| "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc" |
| }; |
| |
| /* Definitions for the function entry mask bits. */ |
| static char *entry_mask_bit[] = |
| { |
| /* Registers 0 and 1 shall not be saved, since they're used to pass back |
| a function's result to its caller... */ |
| "~r0~", "~r1~", |
| /* Registers 2 .. 11 are normal registers. */ |
| "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", |
| /* Registers 12 and 13 are argument and frame pointer and must not |
| be saved by using the entry mask. */ |
| "~ap~", "~fp~", |
| /* Bits 14 and 15 control integer and decimal overflow. */ |
| "IntOvfl", "DecOvfl", |
| }; |
| |
| /* Sign-extend an (unsigned char). */ |
| #define COERCE_SIGNED_CHAR(ch) ((signed char)(ch)) |
| |
| /* Get a 1 byte signed integer. */ |
| #define NEXTBYTE(p) \ |
| (p += 1, FETCH_DATA (info, p), \ |
| COERCE_SIGNED_CHAR(p[-1])) |
| |
| /* Get a 2 byte signed integer. */ |
| #define COERCE16(x) ((int) (((x) ^ 0x8000) - 0x8000)) |
| #define NEXTWORD(p) \ |
| (p += 2, FETCH_DATA (info, p), \ |
| COERCE16 ((p[-1] << 8) + p[-2])) |
| |
| /* Get a 4 byte signed integer. */ |
| #define COERCE32(x) ((int) (((x) ^ 0x80000000) - 0x80000000)) |
| #define NEXTLONG(p) \ |
| (p += 4, FETCH_DATA (info, p), \ |
| (COERCE32 (((((((unsigned) p[-1] << 8) + p[-2]) << 8) + p[-3]) << 8) + p[-4]))) |
| |
| /* Maximum length of an instruction. */ |
| #define MAXLEN 25 |
| |
| struct private |
| { |
| /* Points to first byte not fetched. */ |
| bfd_byte * max_fetched; |
| bfd_byte the_buffer[MAXLEN]; |
| bfd_vma insn_start; |
| OPCODES_SIGJMP_BUF bailout; |
| }; |
| |
| /* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive) |
| to ADDR (exclusive) are valid. Returns 1 for success, longjmps |
| on error. */ |
| #define FETCH_DATA(info, addr) \ |
| ((addr) <= ((struct private *)(info->private_data))->max_fetched \ |
| ? 1 : fetch_data ((info), (addr))) |
| |
| static int |
| fetch_data (struct disassemble_info *info, bfd_byte *addr) |
| { |
| int status; |
| struct private *priv = (struct private *) info->private_data; |
| bfd_vma start = priv->insn_start + (priv->max_fetched - priv->the_buffer); |
| |
| status = (*info->read_memory_func) (start, |
| priv->max_fetched, |
| addr - priv->max_fetched, |
| info); |
| if (status != 0) |
| { |
| (*info->memory_error_func) (status, start, info); |
| OPCODES_SIGLONGJMP (priv->bailout, 1); |
| } |
| else |
| priv->max_fetched = addr; |
| |
| return 1; |
| } |
| |
| /* Entry mask handling. */ |
| static unsigned int entry_addr_occupied_slots = 0; |
| static unsigned int entry_addr_total_slots = 0; |
| static bfd_vma * entry_addr = NULL; |
| |
| /* Parse the VAX specific disassembler options. These contain function |
| entry addresses, which can be useful to disassemble ROM images, since |
| there's no symbol table. Returns TRUE upon success, FALSE otherwise. */ |
| |
| static bool |
| parse_disassembler_options (const char *options) |
| { |
| const char * entry_switch = "entry:"; |
| |
| while ((options = strstr (options, entry_switch))) |
| { |
| options += strlen (entry_switch); |
| |
| /* The greater-than part of the test below is paranoia. */ |
| if (entry_addr_occupied_slots >= entry_addr_total_slots) |
| { |
| /* A guesstimate of the number of entries we will have to create. */ |
| entry_addr_total_slots |
| += 1 + strlen (options) / (strlen (entry_switch) + 5); |
| |
| entry_addr = realloc (entry_addr, sizeof (bfd_vma) |
| * entry_addr_total_slots); |
| } |
| |
| if (entry_addr == NULL) |
| return false; |
| |
| entry_addr[entry_addr_occupied_slots] = bfd_scan_vma (options, NULL, 0); |
| entry_addr_occupied_slots ++; |
| } |
| |
| return true; |
| } |
| |
| #if 0 /* FIXME: Ideally the disassembler should have target specific |
| initialisation and termination function pointers. Then |
| parse_disassembler_options could be the init function and |
| free_entry_array (below) could be the termination routine. |
| Until then there is no way for the disassembler to tell us |
| that it has finished and that we no longer need the entry |
| array, so this routine is suppressed for now. It does mean |
| that we leak memory, but only to the extent that we do not |
| free it just before the disassembler is about to terminate |
| anyway. */ |
| |
| /* Free memory allocated to our entry array. */ |
| |
| static void |
| free_entry_array (void) |
| { |
| if (entry_addr) |
| { |
| free (entry_addr); |
| entry_addr = NULL; |
| entry_addr_occupied_slots = entry_addr_total_slots = 0; |
| } |
| } |
| #endif |
| /* Check if the given address is a known function entry point. This is |
| the case if there is a symbol of the function type at this address. |
| We also check for synthetic symbols as these are used for PLT entries |
| (weak undefined symbols may not have the function type set). Finally |
| the address may have been forced to be treated as an entry point. The |
| latter helps in disassembling ROM images, because there's no symbol |
| table at all. Forced entry points can be given by supplying several |
| -M options to objdump: -M entry:0xffbb7730. */ |
| |
| static bool |
| is_function_entry (struct disassemble_info *info, bfd_vma addr) |
| { |
| unsigned int i; |
| |
| /* Check if there's a function or PLT symbol at our address. */ |
| if (info->symbols |
| && info->symbols[0] |
| && (info->symbols[0]->flags & (BSF_FUNCTION | BSF_SYNTHETIC)) |
| && addr == bfd_asymbol_value (info->symbols[0])) |
| return true; |
| |
| /* Check for forced function entry address. */ |
| for (i = entry_addr_occupied_slots; i--;) |
| if (entry_addr[i] == addr) |
| return true; |
| |
| return false; |
| } |
| |
| /* Check if the given address is the last longword of a PLT entry. |
| This longword is data and depending on the value it may interfere |
| with disassembly of further PLT entries. We make use of the fact |
| PLT symbols are marked BSF_SYNTHETIC. */ |
| static bool |
| is_plt_tail (struct disassemble_info *info, bfd_vma addr) |
| { |
| if (info->symbols |
| && info->symbols[0] |
| && (info->symbols[0]->flags & BSF_SYNTHETIC) |
| && addr == bfd_asymbol_value (info->symbols[0]) + 8) |
| return true; |
| |
| return false; |
| } |
| |
| static int |
| print_insn_mode (const char *d, |
| int size, |
| unsigned char *p0, |
| bfd_vma addr, /* PC for this arg to be relative to. */ |
| disassemble_info *info) |
| { |
| unsigned char *p = p0; |
| unsigned char mode, reg; |
| |
| /* Fetch and interpret mode byte. */ |
| mode = (unsigned char) NEXTBYTE (p); |
| reg = mode & 0xF; |
| switch (mode & 0xF0) |
| { |
| case 0x00: |
| case 0x10: |
| case 0x20: |
| case 0x30: /* Literal mode $number. */ |
| if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h') |
| (*info->fprintf_func) (info->stream, "$0x%x [%c-float]", mode, d[1]); |
| else |
| (*info->fprintf_func) (info->stream, "$0x%x", mode); |
| break; |
| case 0x40: /* Index: base-addr[Rn] */ |
| { |
| unsigned char *q = p0 + 1; |
| unsigned char nextmode = NEXTBYTE (q); |
| if (nextmode < 0x60 || nextmode == 0x8f) |
| /* Literal, index, register, or immediate is invalid. In |
| particular don't recurse into another index mode which |
| might overflow the_buffer. */ |
| (*info->fprintf_func) (info->stream, "[invalid base]"); |
| else |
| p += print_insn_mode (d, size, p0 + 1, addr + 1, info); |
| (*info->fprintf_func) (info->stream, "[%s]", reg_names[reg]); |
| } |
| break; |
| case 0x50: /* Register: Rn */ |
| (*info->fprintf_func) (info->stream, "%s", reg_names[reg]); |
| break; |
| case 0x60: /* Register deferred: (Rn) */ |
| (*info->fprintf_func) (info->stream, "(%s)", reg_names[reg]); |
| break; |
| case 0x70: /* Autodecrement: -(Rn) */ |
| (*info->fprintf_func) (info->stream, "-(%s)", reg_names[reg]); |
| break; |
| case 0x80: /* Autoincrement: (Rn)+ */ |
| if (reg == 0xF) |
| { /* Immediate? */ |
| int i; |
| |
| FETCH_DATA (info, p + size); |
| (*info->fprintf_func) (info->stream, "$0x"); |
| if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h') |
| { |
| int float_word; |
| |
| float_word = p[0] | (p[1] << 8); |
| if ((d[1] == 'd' || d[1] == 'f') |
| && (float_word & 0xff80) == 0x8000) |
| { |
| (*info->fprintf_func) (info->stream, "[invalid %c-float]", |
| d[1]); |
| } |
| else |
| { |
| for (i = 0; i < size; i++) |
| (*info->fprintf_func) (info->stream, "%02x", |
| p[size - i - 1]); |
| (*info->fprintf_func) (info->stream, " [%c-float]", d[1]); |
| } |
| } |
| else |
| { |
| for (i = 0; i < size; i++) |
| (*info->fprintf_func) (info->stream, "%02x", p[size - i - 1]); |
| } |
| p += size; |
| } |
| else |
| (*info->fprintf_func) (info->stream, "(%s)+", reg_names[reg]); |
| break; |
| case 0x90: /* Autoincrement deferred: @(Rn)+ */ |
| if (reg == 0xF) |
| (*info->fprintf_func) (info->stream, "*0x%x", NEXTLONG (p)); |
| else |
| (*info->fprintf_func) (info->stream, "@(%s)+", reg_names[reg]); |
| break; |
| case 0xB0: /* Displacement byte deferred: *displ(Rn). */ |
| (*info->fprintf_func) (info->stream, "*"); |
| /* Fall through. */ |
| case 0xA0: /* Displacement byte: displ(Rn). */ |
| if (reg == 0xF) |
| (*info->print_address_func) (addr + 2 + NEXTBYTE (p), info); |
| else |
| (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTBYTE (p), |
| reg_names[reg]); |
| break; |
| case 0xD0: /* Displacement word deferred: *displ(Rn). */ |
| (*info->fprintf_func) (info->stream, "*"); |
| /* Fall through. */ |
| case 0xC0: /* Displacement word: displ(Rn). */ |
| if (reg == 0xF) |
| (*info->print_address_func) (addr + 3 + NEXTWORD (p), info); |
| else |
| (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTWORD (p), |
| reg_names[reg]); |
| break; |
| case 0xF0: /* Displacement long deferred: *displ(Rn). */ |
| (*info->fprintf_func) (info->stream, "*"); |
| /* Fall through. */ |
| case 0xE0: /* Displacement long: displ(Rn). */ |
| if (reg == 0xF) |
| (*info->print_address_func) (addr + 5 + NEXTLONG (p), info); |
| else |
| (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTLONG (p), |
| reg_names[reg]); |
| break; |
| } |
| |
| return p - p0; |
| } |
| |
| /* Returns number of bytes "eaten" by the operand, or return -1 if an |
| invalid operand was found, or -2 if an opcode tabel error was |
| found. */ |
| |
| static int |
| print_insn_arg (const char *d, |
| unsigned char *p0, |
| bfd_vma addr, /* PC for this arg to be relative to. */ |
| disassemble_info *info) |
| { |
| int arg_len; |
| |
| /* Check validity of addressing length. */ |
| switch (d[1]) |
| { |
| case 'b' : arg_len = 1; break; |
| case 'd' : arg_len = 8; break; |
| case 'f' : arg_len = 4; break; |
| case 'g' : arg_len = 8; break; |
| case 'h' : arg_len = 16; break; |
| case 'l' : arg_len = 4; break; |
| case 'o' : arg_len = 16; break; |
| case 'w' : arg_len = 2; break; |
| case 'q' : arg_len = 8; break; |
| default : abort (); |
| } |
| |
| /* Branches have no mode byte. */ |
| if (d[0] == 'b') |
| { |
| unsigned char *p = p0; |
| |
| if (arg_len == 1) |
| (*info->print_address_func) (addr + 1 + NEXTBYTE (p), info); |
| else |
| (*info->print_address_func) (addr + 2 + NEXTWORD (p), info); |
| |
| return p - p0; |
| } |
| |
| return print_insn_mode (d, arg_len, p0, addr, info); |
| } |
| |
| /* Print the vax instruction at address MEMADDR in debugged memory, |
| on INFO->STREAM. Returns length of the instruction, in bytes. */ |
| |
| int |
| print_insn_vax (bfd_vma memaddr, disassemble_info *info) |
| { |
| static bool parsed_disassembler_options = false; |
| const struct vot *votp; |
| const char *argp; |
| unsigned char *arg; |
| struct private priv; |
| bfd_byte *buffer = priv.the_buffer; |
| |
| info->private_data = & priv; |
| priv.max_fetched = priv.the_buffer; |
| priv.insn_start = memaddr; |
| |
| if (! parsed_disassembler_options |
| && info->disassembler_options != NULL) |
| { |
| parse_disassembler_options (info->disassembler_options); |
| |
| /* To avoid repeated parsing of these options. */ |
| parsed_disassembler_options = true; |
| } |
| |
| if (OPCODES_SIGSETJMP (priv.bailout) != 0) |
| /* Error return. */ |
| return -1; |
| |
| argp = NULL; |
| /* Check if the info buffer has more than one byte left since |
| the last opcode might be a single byte with no argument data. */ |
| if (info->buffer_length - (memaddr - info->buffer_vma) > 1 |
| && (info->stop_vma == 0 || memaddr < (info->stop_vma - 1))) |
| { |
| FETCH_DATA (info, buffer + 2); |
| } |
| else |
| { |
| FETCH_DATA (info, buffer + 1); |
| buffer[1] = 0; |
| } |
| |
| /* Decode function entry mask. */ |
| if (is_function_entry (info, memaddr)) |
| { |
| int i = 0; |
| int register_mask = buffer[1] << 8 | buffer[0]; |
| |
| (*info->fprintf_func) (info->stream, ".word 0x%04x # Entry mask: <", |
| register_mask); |
| |
| for (i = 15; i >= 0; i--) |
| if (register_mask & (1 << i)) |
| (*info->fprintf_func) (info->stream, " %s", entry_mask_bit[i]); |
| |
| (*info->fprintf_func) (info->stream, " >"); |
| |
| return 2; |
| } |
| |
| /* Decode PLT entry offset longword. */ |
| if (is_plt_tail (info, memaddr)) |
| { |
| int offset; |
| |
| FETCH_DATA (info, buffer + 4); |
| offset = ((unsigned) buffer[3] << 24 | buffer[2] << 16 |
| | buffer[1] << 8 | buffer[0]); |
| (*info->fprintf_func) (info->stream, ".long 0x%08x", offset); |
| |
| return 4; |
| } |
| |
| for (votp = &votstrs[0]; votp->name[0]; votp++) |
| { |
| vax_opcodeT opcode = votp->detail.code; |
| |
| /* 2 byte codes match 2 buffer pos. */ |
| if ((bfd_byte) opcode == buffer[0] |
| && (opcode >> 8 == 0 || opcode >> 8 == buffer[1])) |
| { |
| argp = votp->detail.args; |
| break; |
| } |
| } |
| if (argp == NULL) |
| { |
| /* Handle undefined instructions. */ |
| (*info->fprintf_func) (info->stream, ".word 0x%x", |
| (buffer[0] << 8) + buffer[1]); |
| return 2; |
| } |
| |
| /* Point at first byte of argument data, and at descriptor for first |
| argument. */ |
| arg = buffer + ((votp->detail.code >> 8) ? 2 : 1); |
| |
| /* Make sure we have it in mem */ |
| FETCH_DATA (info, arg); |
| |
| (*info->fprintf_func) (info->stream, "%s", votp->name); |
| if (*argp) |
| (*info->fprintf_func) (info->stream, " "); |
| |
| while (*argp) |
| { |
| arg += print_insn_arg (argp, arg, memaddr + (arg - buffer), info); |
| argp += 2; |
| if (*argp) |
| (*info->fprintf_func) (info->stream, ","); |
| } |
| |
| return arg - buffer; |
| } |
| |