from collections import Counter from enum import IntEnum class AddrMode(IntEnum): Imp = 1, Acc = 2, Imm = 3, Zp = 4, ZpX = 5, ZpY = 6, Rel = 7, Abs = 8, AbsX = 9, AbsY = 10, Ind = 11, IzX = 12, IzY = 13, Zpr = 14, Izp = 15, IaX = 16 AllInstructions = [ (0x00, "brk", AddrMode.Imp), (0x01, "ora", AddrMode.IzX), (0x02, "nop", AddrMode.Imm), (0x03, "nop", AddrMode.Imp), (0x04, "tsb", AddrMode.Zp), (0x05, "ora", AddrMode.Zp), (0x06, "asl", AddrMode.Zp), (0x07, "rmb0", AddrMode.Zp), (0x08, "php", AddrMode.Imp), (0x09, "ora", AddrMode.Imm), (0x0a, "asl", AddrMode.Acc), (0x0b, "nop", AddrMode.Imp), (0x0c, "tsb", AddrMode.Abs), (0x0d, "ora", AddrMode.Abs), (0x0e, "asl", AddrMode.Abs), (0x0f, "bbr0", AddrMode.Zpr), (0x10, "bpl", AddrMode.Rel), (0x11, "ora", AddrMode.IzY), (0x12, "ora", AddrMode.Izp), (0x13, "nop", AddrMode.Imp), (0x14, "trb", AddrMode.Zp), (0x15, "ora", AddrMode.ZpX), (0x16, "asl", AddrMode.ZpX), (0x17, "rmb1", AddrMode.Zp), (0x18, "clc", AddrMode.Imp), (0x19, "ora", AddrMode.AbsY), (0x1a, "inc", AddrMode.Acc), (0x1b, "nop", AddrMode.Imp), (0x1c, "trb", AddrMode.Abs), (0x1d, "ora", AddrMode.AbsX), (0x1e, "asl", AddrMode.AbsX), (0x1f, "bbr1", AddrMode.Zpr), (0x20, "jsr", AddrMode.Abs), (0x21, "and", AddrMode.IzX), (0x22, "nop", AddrMode.Imm), (0x23, "nop", AddrMode.Imp), (0x24, "bit", AddrMode.Zp), (0x25, "and", AddrMode.Zp), (0x26, "rol", AddrMode.Zp), (0x27, "rmb2", AddrMode.Zp), (0x28, "plp", AddrMode.Imp), (0x29, "and", AddrMode.Imm), (0x2a, "rol", AddrMode.Acc), (0x2b, "nop", AddrMode.Imp), (0x2c, "bit", AddrMode.Abs), (0x2d, "and", AddrMode.Abs), (0x2e, "rol", AddrMode.Abs), (0x2f, "bbr2", AddrMode.Zpr), (0x30, "bmi", AddrMode.Rel), (0x31, "and", AddrMode.IzY), (0x32, "and", AddrMode.Izp), (0x33, "nop", AddrMode.Imp), (0x34, "bit", AddrMode.ZpX), (0x35, "and", AddrMode.ZpX), (0x36, "rol", AddrMode.ZpX), (0x37, "rmb3", AddrMode.Zp), (0x38, "sec", AddrMode.Imp), (0x39, "and", AddrMode.AbsY), (0x3a, "dec", AddrMode.Acc), (0x3b, "nop", AddrMode.Imp), (0x3c, "bit", AddrMode.AbsX), (0x3d, "and", AddrMode.AbsX), (0x3e, "rol", AddrMode.AbsX), (0x3f, "bbr3", AddrMode.Zpr), (0x40, "rti", AddrMode.Imp), (0x41, "eor", AddrMode.IzX), (0x42, "nop", AddrMode.Imm), (0x43, "nop", AddrMode.Imp), (0x44, "nop", AddrMode.Zp), (0x45, "eor", AddrMode.Zp), (0x46, "lsr", AddrMode.Zp), (0x47, "rmb4", AddrMode.Zp), (0x48, "pha", AddrMode.Imp), (0x49, "eor", AddrMode.Imm), (0x4a, "lsr", AddrMode.Acc), (0x4b, "nop", AddrMode.Imp), (0x4c, "jmp", AddrMode.Abs), (0x4d, "eor", AddrMode.Abs), (0x4e, "lsr", AddrMode.Abs), (0x4f, "bbr4", AddrMode.Zpr), (0x50, "bvc", AddrMode.Rel), (0x51, "eor", AddrMode.IzY), (0x52, "eor", AddrMode.Izp), (0x53, "nop", AddrMode.Imp), (0x54, "nop", AddrMode.ZpX), (0x55, "eor", AddrMode.ZpX), (0x56, "lsr", AddrMode.ZpX), (0x57, "rmb5", AddrMode.Zp), (0x58, "cli", AddrMode.Imp), (0x59, "eor", AddrMode.AbsY), (0x5a, "phy", AddrMode.Imp), (0x5b, "nop", AddrMode.Imp), (0x5c, "nop", AddrMode.Abs), (0x5d, "eor", AddrMode.AbsX), (0x5e, "lsr", AddrMode.AbsX), (0x5f, "bbr5", AddrMode.Zpr), (0x60, "rts", AddrMode.Imp), (0x61, "adc", AddrMode.IzX), (0x62, "nop", AddrMode.Imm), (0x63, "nop", AddrMode.Imp), (0x64, "stz", AddrMode.Zp), (0x65, "adc", AddrMode.Zp), (0x66, "ror", AddrMode.Zp), (0x67, "rmb6", AddrMode.Zp), (0x68, "pla", AddrMode.Imp), (0x69, "adc", AddrMode.Imm), (0x6a, "ror", AddrMode.Acc), (0x6b, "nop", AddrMode.Imp), (0x6c, "jmp", AddrMode.Ind), (0x6d, "adc", AddrMode.Abs), (0x6e, "ror", AddrMode.Abs), (0x6f, "bbr6", AddrMode.Zpr), (0x70, "bvs", AddrMode.Rel), (0x71, "adc", AddrMode.IzY), (0x72, "adc", AddrMode.Izp), (0x73, "nop", AddrMode.Imp), (0x74, "stz", AddrMode.ZpX), (0x75, "adc", AddrMode.ZpX), (0x76, "ror", AddrMode.ZpX), (0x77, "rmb7", AddrMode.Zp), (0x78, "sei", AddrMode.Imp), (0x79, "adc", AddrMode.AbsY), (0x7a, "ply", AddrMode.Imp), (0x7b, "nop", AddrMode.Imp), (0x7c, "jmp", AddrMode.IaX), (0x7d, "adc", AddrMode.AbsX), (0x7e, "ror", AddrMode.AbsX), (0x7f, "bbr7", AddrMode.Zpr), (0x80, "bra", AddrMode.Rel), (0x81, "sta", AddrMode.IzX), (0x82, "nop", AddrMode.Imm), (0x83, "nop", AddrMode.Imp), (0x84, "sty", AddrMode.Zp), (0x85, "sta", AddrMode.Zp), (0x86, "stx", AddrMode.Zp), (0x87, "smb0", AddrMode.Zp), (0x88, "dey", AddrMode.Imp), (0x89, "bit", AddrMode.Imm), (0x8a, "txa", AddrMode.Imp), (0x8b, "nop", AddrMode.Imp), (0x8c, "sty", AddrMode.Abs), (0x8d, "sta", AddrMode.Abs), (0x8e, "stx", AddrMode.Abs), (0x8f, "bbs0", AddrMode.Zpr), (0x90, "bcc", AddrMode.Rel), (0x91, "sta", AddrMode.IzY), (0x92, "sta", AddrMode.Izp), (0x93, "nop", AddrMode.Imp), (0x94, "sty", AddrMode.ZpX), (0x95, "sta", AddrMode.ZpX), (0x96, "stx", AddrMode.ZpY), (0x97, "smb1", AddrMode.Zp), (0x98, "tya", AddrMode.Imp), (0x99, "sta", AddrMode.AbsY), (0x9a, "txs", AddrMode.Imp), (0x9b, "nop", AddrMode.Imp), (0x9c, "stz", AddrMode.Abs), (0x9d, "sta", AddrMode.AbsX), (0x9e, "stz", AddrMode.AbsX), (0x9f, "bbs1", AddrMode.Zpr), (0xa0, "ldy", AddrMode.Imm), (0xa1, "lda", AddrMode.IzX), (0xa2, "ldx", AddrMode.Imm), (0xa3, "nop", AddrMode.Imp), (0xa4, "ldy", AddrMode.Zp), (0xa5, "lda", AddrMode.Zp), (0xa6, "ldx", AddrMode.Zp), (0xa7, "smb2", AddrMode.Zp), (0xa8, "tay", AddrMode.Imp), (0xa9, "lda", AddrMode.Imm), (0xaa, "tax", AddrMode.Imp), (0xab, "nop", AddrMode.Imp), (0xac, "ldy", AddrMode.Abs), (0xad, "lda", AddrMode.Abs), (0xae, "ldx", AddrMode.Abs), (0xaf, "bbs2", AddrMode.Zpr), (0xb0, "bcs", AddrMode.Rel), (0xb1, "lda", AddrMode.IzY), (0xb2, "lda", AddrMode.Izp), (0xb3, "nop", AddrMode.Imp), (0xb4, "ldy", AddrMode.ZpX), (0xb5, "lda", AddrMode.ZpX), (0xb6, "ldx", AddrMode.ZpY), (0xb7, "smb3", AddrMode.Zp), (0xb8, "clv", AddrMode.Imp), (0xb9, "lda", AddrMode.AbsY), (0xba, "tsx", AddrMode.Imp), (0xbb, "nop", AddrMode.Imp), (0xbc, "ldy", AddrMode.AbsX), (0xbd, "lda", AddrMode.AbsX), (0xbe, "ldx", AddrMode.AbsY), (0xbf, "bbs3", AddrMode.Zpr), (0xc0, "cpy", AddrMode.Imm), (0xc1, "cmp", AddrMode.IzX), (0xc2, "nop", AddrMode.Imm), (0xc3, "nop", AddrMode.Imp), (0xc4, "cpy", AddrMode.Zp), (0xc5, "cmp", AddrMode.Zp), (0xc6, "dec", AddrMode.Zp), (0xc7, "smb4", AddrMode.Zp), (0xc8, "iny", AddrMode.Imp), (0xc9, "cmp", AddrMode.Imm), (0xca, "dex", AddrMode.Imp), (0xcb, "wai", AddrMode.Imp), (0xcc, "cpy", AddrMode.Abs), (0xcd, "cmp", AddrMode.Abs), (0xce, "dec", AddrMode.Abs), (0xcf, "bbs4", AddrMode.Zpr), (0xd0, "bne", AddrMode.Rel), (0xd1, "cmp", AddrMode.IzY), (0xd2, "cmp", AddrMode.Izp), (0xd3, "nop", AddrMode.Imp), (0xd4, "nop", AddrMode.ZpX), (0xd5, "cmp", AddrMode.ZpX), (0xd6, "dec", AddrMode.ZpX), (0xd7, "smb5", AddrMode.Zp), (0xd8, "cld", AddrMode.Imp), (0xd9, "cmp", AddrMode.AbsY), (0xda, "phx", AddrMode.Imp), (0xdb, "stp", AddrMode.Imp), (0xdc, "nop", AddrMode.Abs), (0xdd, "cmp", AddrMode.AbsX), (0xde, "dec", AddrMode.AbsX), (0xdf, "bbs5", AddrMode.Zpr), (0xe0, "cpx", AddrMode.Imm), (0xe1, "sbc", AddrMode.IzX), (0xe2, "nop", AddrMode.Imm), (0xe3, "nop", AddrMode.Imp), (0xe4, "cpx", AddrMode.Zp), (0xe5, "sbc", AddrMode.Zp), (0xe6, "inc", AddrMode.Zp), (0xe7, "smb6", AddrMode.Zp), (0xe8, "inx", AddrMode.Imp), (0xe9, "sbc", AddrMode.Imm), (0xea, "nop", AddrMode.Imp), (0xeb, "nop", AddrMode.Imp), (0xec, "cpx", AddrMode.Abs), (0xed, "sbc", AddrMode.Abs), (0xee, "inc", AddrMode.Abs), (0xef, "bbs6", AddrMode.Zpr), (0xf0, "beq", AddrMode.Rel), (0xf1, "sbc", AddrMode.IzY), (0xf2, "sbc", AddrMode.Izp), (0xf3, "nop", AddrMode.Imp), (0xf4, "nop", AddrMode.ZpX), (0xf5, "sbc", AddrMode.ZpX), (0xf6, "inc", AddrMode.ZpX), (0xf7, "smb7", AddrMode.Zp), (0xf8, "sed", AddrMode.Imp), (0xf9, "sbc", AddrMode.AbsY), (0xfa, "plx", AddrMode.Imp), (0xfb, "nop", AddrMode.Imp), (0xfc, "nop", AddrMode.AbsX), (0xfd, "sbc", AddrMode.AbsX), (0xfe, "inc", AddrMode.AbsX), (0xff, "bbs7", AddrMode.Zpr) ] # NOP is weird, it is all over the place. # For the 'common' immediate NOP, keep only the $EA opcode (this was the original NOP on the 6502) Instructions = [ins for ins in AllInstructions if ins[1] != "nop"] + [(0xea, "nop", AddrMode.Imp)] InstructionsByName = {} for ins in Instructions: if ins[1] not in InstructionsByName: InstructionsByName[ins[1]] = {ins[2]: ins[0]} else: InstructionsByName[ins[1]][ins[2]] = ins[0] InstructionsByMode = {} for ins in Instructions: if ins[2] not in InstructionsByMode: InstructionsByMode[ins[2]] = [(ins[1], ins[0])] else: InstructionsByMode[ins[2]].append((ins[1], ins[0])) # build the name->modes table print("; generated by opcodes.py") print("; addressing modes:") for mode in AddrMode: print(";", mode.value, "=", mode.name) print() print(""" .enc "petscii" ;define an ascii to petscii encoding .cdef " @", 32 ;characters .cdef "AZ", $c1 .cdef "az", $41 .cdef "[[", $5b .cdef "]]", $5d .edef "", [];replace with no bytes """) for instr in sorted(InstructionsByName.items()): print("i_" + instr[0] + ":\n\t.byte ", end="") if len(instr[1]) == 1: # many instructions have just 1 addressing mode, save space for those info = instr[1].popitem() print("1,", info[0].value,",", info[1]) else: print("0, ", end='') mode_opcodes = [] for mode in AddrMode: if mode in instr[1]: mode_opcodes.append(instr[1][mode]) else: mode_opcodes.append(0) print(",".join(str(o) for o in mode_opcodes), end="") print() def determine_mnemonics(): mnemonics = list(sorted(set(ins[1] for ins in Instructions))) # opcodes histogram (ordered by occurrence) (in kernal + basic roms of the c64): opcode_occurrences = [ (32, 839), (133, 502), (165, 488), (0, 429), (208, 426), (169, 390), (76, 324), (240, 322), (2, 314), (160, 245), (96, 228), (3, 201), (1, 191), (255, 186), (144, 182), (170, 175), (162, 169), (177, 165), (104, 159), (164, 158), (132, 157), (201, 156), (72, 151), (141, 150), (200, 146), (173, 144), (166, 139), (176, 139), (16, 138), (134, 138), (73, 127), (24, 119), (101, 113), (69, 109), (13, 107), (34, 104), (145, 103), (4, 102), (168, 101), (221, 98), (230, 93), (48, 91), (189, 87), (41, 86), (6, 86), (9, 86), (8, 85), (79, 85), (138, 80), (10, 80), (7, 79), (185, 77), (56, 75), (44, 75), (78, 74), (105, 73), (5, 73), (174, 73), (220, 71), (198, 69), (232, 69), (36, 69), (202, 67), (152, 67), (95, 67), (100, 65), (102, 65), (247, 65), (188, 64), (136, 64), (84, 64), (122, 62), (128, 61), (80, 61), (186, 60), (82, 59), (97, 58), (15, 57), (70, 57), (229, 56), (19, 55), (40, 54), (183, 54), (65, 54), (233, 53), (180, 53), (12, 53), (171, 53), (197, 53), (83, 52), (248, 52), (112, 51), (237, 51), (89, 50), (11, 50), (158, 50), (74, 49), (224, 48), (20, 47), (238, 47), (108, 46), (234, 46), (251, 46), (254, 46), (184, 45), (14, 44), (163, 44), (226, 43), (211, 43), (88, 43), (98, 42), (17, 42), (153, 42), (243, 41), (228, 41), (99, 41), (253, 41), (209, 41), (187, 39), (123, 39), (67, 39), (196, 38), (68, 38), (35, 38), (172, 38), (175, 38), (161, 38), (85, 38), (191, 37), (113, 37), (182, 37), (151, 37), (71, 36), (181, 35), (214, 35), (121, 35), (157, 35), (178, 35), (77, 35), (42, 34), (212, 33), (18, 33), (127, 33), (241, 33), (21, 33), (249, 32), (23, 31), (245, 30), (142, 30), (55, 29), (140, 29), (46, 29), (192, 29), (179, 29), (252, 29), (115, 29), (22, 29), (43, 28), (215, 28), (45, 28), (246, 28), (38, 28), (86, 27), (225, 27), (25, 26), (239, 26), (58, 26), (167, 26), (147, 26), (217, 26), (149, 25), (30, 25), (206, 25), (28, 24), (47, 24), (37, 24), (155, 24), (129, 23), (148, 23), (111, 23), (29, 23), (39, 23), (51, 22), (193, 22), (236, 22), (120, 22), (64, 22), (204, 21), (210, 21), (244, 21), (52, 21), (66, 21), (114, 20), (250, 20), (106, 20), (93, 19), (199, 19), (218, 19), (154, 19), (205, 19), (50, 19), (159, 19), (194, 19), (49, 19), (190, 19), (103, 18), (216, 18), (213, 18), (107, 18), (131, 18), (63, 18), (94, 18), (91, 17), (242, 17), (109, 17), (53, 16), (227, 16), (139, 16), (31, 16), (75, 16), (60, 16), (195, 15), (231, 15), (62, 15), (59, 15), (87, 14), (207, 14), (27, 14), (90, 14), (110, 13), (223, 13), (57, 13), (118, 12), (26, 12), (203, 12), (81, 12), (156, 12), (54, 12), (235, 12), (146, 11), (135, 11), (126, 11), (150, 11), (130, 11), (143, 10), (61, 10), (219, 10), (124, 9), (222, 9), (125, 9), (119, 7), (137, 7), (33, 7), (117, 5), (92, 4), (116, 3) ] cnt = Counter() for opcode, amount in opcode_occurrences: cnt[AllInstructions[opcode][1]] += amount cnt["nop"] = 13 cnt["tsb"] = 13 four_letter_mnemonics = list(sorted([ins[1] for ins in AllInstructions if len(ins[1])>3])) for ins4 in four_letter_mnemonics: del cnt[ins4] cnt[ins4] = 1 mnem2 = [c[0] for c in cnt.most_common()] if len(mnem2)!=len(mnemonics): raise ValueError("mnem count mismatch") return mnem2 mnemonics = determine_mnemonics() def first_letters(): firstletters = {m[0]: 0 for m in mnemonics} return firstletters.keys() def second_letters(firstletter): secondletters = {m[1]: 0 for m in mnemonics if m[0] == firstletter} return secondletters.keys() def third_letters(firstletter, secondletter): thirdletters = {m[2]: 0 for m in mnemonics if m[0] == firstletter and m[1] == secondletter} return thirdletters.keys() def fourth_letters(firstletter, secondletter, thirdletter): longmnem = [m for m in mnemonics if len(m) > 3] fourthletters = {m[3]: 0 for m in longmnem if m[0] == firstletter and m[1] == secondletter and m[2] == thirdletter} return fourthletters.keys() def make_tree(): tree = {} for first in first_letters(): tree[first] = { secondletter: { thirdletter: { fourthletter: {} for fourthletter in fourth_letters(first, secondletter, thirdletter) } for thirdletter in third_letters(first, secondletter) } for secondletter in second_letters(first) } return tree tree = make_tree() print("get_opcode_info .proc") print("_mnem_fourth_letter = cx16.r4") print("_mnem_fifth_letter = cx16.r5") for first in tree: print(" cmp #'%s'" % first) print(" bne _not_%s" % first) for second in tree[first]: print(" cpx #'%s'" % second) print(" bne _not_%s%s" % (first,second)) for third in tree[first][second]: print(" cpy #'%s'" % third) print(" bne _not_%s%s%s" % (first, second, third)) fourth = tree[first][second][third] if fourth: if "".join(fourth.keys()) != "01234567": raise ValueError("fourth", fourth.keys()) print(" bra _check_%s%s%s" % (first, second, third)) else: print(" lda _mnem_fourth_letter") # check that the fourth letter is not present print(" bne _invalid") print(" lda #i_%s%s%s" % (first, second, third)) print(" rts") print("_not_%s%s%s:" % (first, second, third)) print("_not_%s%s:" % (first, second)) print("_not_%s:" % first) print("_invalid:") print(" lda #0") print(" ldy #0") print(" rts") # the 4-letter mnemonics are: # smb[0-7] # bbr[0-7] # rmb[0-7] # bbs[0-7] for fourlettermnemonic in ["smb", "bbr", "rmb", "bbs"]: print("_check_%s" % fourlettermnemonic) print(" lda #<_tab_%s" % fourlettermnemonic) print(" ldy #>_tab_%s" % fourlettermnemonic) print(""" sta P8ZP_SCRATCH_W2 sty P8ZP_SCRATCH_W2+1 bra _check4""") print("""_check4 lda _mnem_fourth_letter cmp #'0' bcc _invalid cmp #'8' bcs _invalid lda _mnem_fifth_letter ; must have no fifth letter bne _invalid tay lda (P8ZP_SCRATCH_W2),y pha iny lda (P8ZP_SCRATCH_W2),y tay pla rts""") for fourlettermnemonic in ["smb", "bbr", "rmb", "bbs"]: print("_tab_%s" % fourlettermnemonic) for ii in "01234567": print(" .word i_%s%s" % (fourlettermnemonic, ii)) print(" .pend")