diff options
Diffstat (limited to 'assemble.c')
| -rw-r--r-- | assemble.c | 148 |
1 files changed, 141 insertions, 7 deletions
@@ -32,12 +32,19 @@ * \70, \71, \72 - a long relative operand, from operand 0, 1 or 2 * \1ab - a ModRM, calculated on EA in operand a, with the spare * field the register value of operand b. + * \130,\131,\132 - an immediate word or signed byte for operand 0, 1, or 2 + * \133,\134,\135 - or 2 (s-field) into next opcode byte if operand 0, 1, or 2 + * is a signed byte rather than a word. + * \140,\141,\142 - an immediate dword or signed byte for operand 0, 1, or 2 + * \143,\144,\145 - or 2 (s-field) into next opcode byte if operand 0, 1, or 2 + * is a signed byte rather than a dword. * \2ab - a ModRM, calculated on EA in operand a, with the spare * field equal to digit b. * \30x - might be an 0x67 byte, depending on the address size of * the memory reference in operand x. * \310 - indicates fixed 16-bit address size, i.e. optional 0x67. * \311 - indicates fixed 32-bit address size, i.e. optional 0x67. + * \312 - (disassembler only) marker on LOOP, LOOPxx instructions. * \320 - indicates fixed 16-bit operand size, i.e. optional 0x66. * \321 - indicates fixed 32-bit operand size, i.e. optional 0x66. * \322 - indicates that this instruction is only valid when the @@ -52,6 +59,9 @@ * as a literal byte in order to aid the disassembler. * \340 - reserve <operand 0> bytes of uninitialised storage. * Operand 0 had better be a segmentless constant. + * \370,\371,\372 - match only if operand 0, 1, 2 meets byte jump criteria. + * \373 - assemble 0x03 if bits==16, 0x05 if bits==32; + * used for conditional jump over longer jump */ #include <stdio.h> @@ -71,6 +81,7 @@ typedef struct { unsigned char modrm, sib; /* the bytes themselves */ } ea; +static unsigned long cpu; /* cpu level received from nasm.c */ static efunc errfunc; static struct ofmt *outfmt; static ListGen *list; @@ -134,7 +145,25 @@ static void out (long offset, long segto, void *data, unsigned long type, outfmt->output (segto, data, type, segment, wrt); } -long assemble (long segment, long offset, int bits, +static int jmp_match (long segment, long offset, int bits, + insn *ins, char *code) +{ long isize; + unsigned char c = code[0]; + + + if (c != 0370) return 0; + if (ins->oprs[0].opflags & OPFLAG_FORWARD) return 1; /* match a forward reference */ + + isize = calcsize (segment, offset, bits, ins, code); + if (ins->oprs[0].segment != segment) return 0; + isize = ins->oprs[0].offset - offset - isize; /* isize is now the delta */ + if (isize >= -128L && isize <= 127L) return 1; /* it is byte size */ + + return 0; +} + + +long assemble (long segment, long offset, int bits, unsigned long cp, insn *instruction, struct ofmt *output, efunc error, ListGen *listgen) { @@ -147,6 +176,7 @@ long assemble (long segment, long offset, int bits, long wsize = 0; /* size for DB etc. */ errfunc = error; /* to pass to other functions */ + cpu = cp; outfmt = output; /* likewise */ list = listgen; /* and again */ @@ -305,6 +335,8 @@ long assemble (long segment, long offset, int bits, temp = nasm_instructions[instruction->opcode]; while (temp->opcode != -1) { int m = matches (temp, instruction); + if (m == 99) + m += jmp_match(segment, offset, bits, instruction, temp->code); if (m == 100) /* matches! */ { @@ -371,7 +403,7 @@ long assemble (long segment, long offset, int bits, if (instruction->times > 1) list->downlevel (LIST_TIMES); return offset - start; - } else if (m > 0) { + } else if (m > 0 && m > size_prob) { size_prob = m; } temp++; @@ -382,6 +414,8 @@ long assemble (long segment, long offset, int bits, error (ERR_NONFATAL, "operation size not specified"); else if (size_prob == 2) error (ERR_NONFATAL, "mismatch in operand sizes"); + else if (size_prob == 3) + error (ERR_NONFATAL, "no instruction for this cpu level"); else error (ERR_NONFATAL, "invalid combination of opcode and operands"); @@ -389,12 +423,13 @@ long assemble (long segment, long offset, int bits, return 0; } -long insn_size (long segment, long offset, int bits, +long insn_size (long segment, long offset, int bits, unsigned long cp, insn *instruction, efunc error) { struct itemplate *temp; errfunc = error; /* to pass to other functions */ + cpu = cp; if (instruction->opcode == -1) return 0; @@ -472,7 +507,11 @@ long insn_size (long segment, long offset, int bits, temp = nasm_instructions[instruction->opcode]; while (temp->opcode != -1) { - if (matches(temp, instruction) == 100) { + int m = matches(temp, instruction); + if (m == 99) + m += jmp_match(segment, offset, bits, instruction, temp->code); + + if (m == 100) { /* we've matched an instruction. */ long isize; char * codes = temp->code; @@ -498,6 +537,22 @@ long insn_size (long segment, long offset, int bits, return -1; /* didn't match any instruction */ } + +/* check that opn[op] is a signed byte of size 16 or 32, + and return the signed value*/ +static int is_sbyte (insn *ins, int op, int size) +{ + signed long v; + int ret; + + ret = !(ins->forw_ref && ins->oprs[op].opflags ) && /* dead in the water on forward reference or External */ + ins->oprs[op].wrt==NO_SEG && ins->oprs[op].segment==NO_SEG; + v = ins->oprs[op].offset; + if (size==16) v = (signed short)v; /* sign extend if 16 bits */ + + return ret && v>=-128L && v<=127L; +} + static long calcsize (long segment, long offset, int bits, insn *ins, char *codes) { @@ -540,6 +595,14 @@ static long calcsize (long segment, long offset, int bits, ins->oprs[c-064].addr_size : bits) == 16 ? 2 : 4); break; case 070: case 071: case 072: length += 4; break; + case 0130: case 0131: case 0132: + length += is_sbyte(ins, c-0130, 16) ? 1 : 2; break; + case 0133: case 0134: case 0135: + codes+=2; length++; break; + case 0140: case 0141: case 0142: + length += is_sbyte(ins, c-0140, 32) ? 1 : 4; break; + case 0143: case 0144: case 0145: + codes+=2; length++; break; case 0300: case 0301: case 0302: length += chsize (&ins->oprs[c-0300], bits); break; @@ -573,6 +636,10 @@ static long calcsize (long segment, long offset, int bits, else length += ins->oprs[0].offset << (c-0340); break; + case 0370: case 0371: case 0372: + break; + case 0373: + length++; break; default: /* can't do it by 'case' statements */ if (c>=0100 && c<=0277) { /* it's an EA */ ea ea_data; @@ -801,6 +868,51 @@ static void gencode (long segment, long offset, int bits, offset += 4; break; + case 0130: case 0131: case 0132: + data = ins->oprs[c-0130].offset; + if (is_sbyte(ins, c-0130, 16)) { + out (offset, segment, &data, OUT_RAWDATA+1, NO_SEG, NO_SEG); + offset++; + } else { + if (ins->oprs[c-0130].segment == NO_SEG && + ins->oprs[c-0130].wrt == NO_SEG && + (data < -65536L || data > 65535L)) { + errfunc (ERR_WARNING, "word value exceeds bounds"); + } + out (offset, segment, &data, OUT_ADDRESS+2, + ins->oprs[c-0130].segment, ins->oprs[c-0130].wrt); + offset += 2; + } + break; + + case 0133: case 0134: case 0135: + codes++; + bytes[0] = *codes++; + if (is_sbyte(ins, c-0133, 16)) bytes[0] |= 2; /* s-bit */ + out (offset, segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG); + offset++; + break; + + case 0140: case 0141: case 0142: + data = ins->oprs[c-0140].offset; + if (is_sbyte(ins, c-0140, 32)) { + out (offset, segment, &data, OUT_RAWDATA+1, NO_SEG, NO_SEG); + offset++; + } else { + out (offset, segment, &data, OUT_ADDRESS+4, + ins->oprs[c-0140].segment, ins->oprs[c-0140].wrt); + offset += 4; + } + break; + + case 0143: case 0144: case 0145: + codes++; + bytes[0] = *codes++; + if (is_sbyte(ins, c-0143, 32)) bytes[0] |= 2; /* s-bit */ + out (offset, segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG); + offset++; + break; + case 0300: case 0301: case 0302: if (chsize (&ins->oprs[c-0300], bits)) { *bytes = 0x67; @@ -858,7 +970,7 @@ static void gencode (long segment, long offset, int bits, break; case 0330: - *bytes = *codes++ + condval[ins->condition]; + *bytes = *codes++ ^ condval[ins->condition]; out (offset, segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG); offset += 1; @@ -887,6 +999,16 @@ static void gencode (long segment, long offset, int bits, } break; + case 0370: case 0371: case 0372: + break; + + case 0373: + *bytes = bits==16 ? 3 : 5; + out (offset, segment, bytes, + OUT_RAWDATA+1, NO_SEG, NO_SEG); + offset += 1; + break; + default: /* can't do it by 'case' statements */ if (c>=0100 && c<=0277) { /* it's an EA */ ea ea_data; @@ -1014,7 +1136,8 @@ static int matches (struct itemplate *itemp, insn *instruction) (instruction->oprs[i].type & SIZE_MASK)) return 0; else - ret = 1; +/* ret = 1; */ + return 1; } /* @@ -1069,8 +1192,19 @@ static int matches (struct itemplate *itemp, insn *instruction) for (i=0; i<itemp->operands; i++) if (!(itemp->opd[i] & SIZE_MASK) && (instruction->oprs[i].type & SIZE_MASK & ~size[i])) - ret = 2; +/* ret = 2; */ + return 2; + /* + * Check template is okay at the set cpu level + */ + if ((itemp->flags & IF_PLEVEL) > cpu) return 3; + + /* + * Check if special handling needed for Jumps + */ + if ((unsigned char)(itemp->code[0]) >= 0370) return 99; + return ret; } |