code_6502: Ruby parsing library

This spec can be used to disassemble raw stream of 6502 CPU machine code into individual operations. Each operation includes an opcode and, optionally, an argument. Register arguments are part of the opcode enum.

KS implementation details

License: CC0-1.0

This page hosts a formal specification of code_6502 using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Parse a local file and get structure in memory:

data = Code6502.from_file("path/to/local/file.code_6502")

Or parse structure from a string of bytes:

bytes = "\x00\x01\x02..."
data = Code6502.new(Kaitai::Struct::Stream.new(bytes))

After that, one can get various attributes from the structure by invoking getter methods like:

data.operations # => get operations

Ruby source code to parse code_6502

code_6502.rb

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

require 'kaitai/struct/struct'

unless Gem::Version.new(Kaitai::Struct::VERSION) >= Gem::Version.new('0.7')
  raise "Incompatible Kaitai Struct Ruby API: 0.7 or later is required, but you have #{Kaitai::Struct::VERSION}"
end


##
# This spec can be used to disassemble raw stream of 6502 CPU machine
# code into individual operations. Each operation includes an opcode
# and, optionally, an argument. Register arguments are part of the
# `opcode` enum.
class Code6502 < Kaitai::Struct::Struct

  OPCODE = {
    0 => :opcode_brk_impl,
    1 => :opcode_ora_x_ind,
    5 => :opcode_ora_zpg,
    6 => :opcode_asl_zpg,
    8 => :opcode_php_impl,
    9 => :opcode_ora_imm,
    10 => :opcode_asl_a,
    13 => :opcode_ora_abs,
    14 => :opcode_asl_abs,
    16 => :opcode_bpl_rel,
    17 => :opcode_ora_ind_y,
    21 => :opcode_ora_zpg_x,
    22 => :opcode_asl_zpg_x,
    24 => :opcode_clc_impl,
    25 => :opcode_ora_abs_y,
    29 => :opcode_ora_abs_x,
    30 => :opcode_asl_abs_x,
    32 => :opcode_jsr_abs,
    33 => :opcode_and_x_ind,
    36 => :opcode_bit_zpg,
    37 => :opcode_and_zpg,
    38 => :opcode_rol_zpg,
    40 => :opcode_plp_impl,
    41 => :opcode_and_imm,
    42 => :opcode_rol_a,
    44 => :opcode_bit_abs,
    45 => :opcode_and_abs,
    46 => :opcode_rol_abs,
    48 => :opcode_bmi_rel,
    49 => :opcode_and_ind_y,
    53 => :opcode_and_zpg_x,
    54 => :opcode_rol_zpg_x,
    56 => :opcode_sec_impl,
    57 => :opcode_and_abs_y,
    61 => :opcode_and_abs_x,
    62 => :opcode_rol_abs_x,
    64 => :opcode_rti_impl,
    65 => :opcode_eor_x_ind,
    69 => :opcode_eor_zpg,
    70 => :opcode_lsr_zpg,
    72 => :opcode_pha_impl,
    73 => :opcode_eor_imm,
    74 => :opcode_lsr_a,
    76 => :opcode_jmp_abs,
    77 => :opcode_eor_abs,
    78 => :opcode_lsr_abs,
    80 => :opcode_bvc_rel,
    81 => :opcode_eor_ind_y,
    85 => :opcode_eor_zpg_x,
    86 => :opcode_lsr_zpg_x,
    88 => :opcode_cli_impl,
    89 => :opcode_eor_abs_y,
    93 => :opcode_eor_abs_x,
    94 => :opcode_lsr_abs_x,
    96 => :opcode_rts_impl,
    97 => :opcode_adc_x_ind,
    101 => :opcode_adc_zpg,
    102 => :opcode_ror_zpg,
    104 => :opcode_pla_impl,
    105 => :opcode_adc_imm,
    106 => :opcode_ror_a,
    108 => :opcode_jmp_ind,
    109 => :opcode_adc_abs,
    110 => :opcode_ror_abs,
    112 => :opcode_bvs_rel,
    113 => :opcode_adc_ind_y,
    117 => :opcode_adc_zpg_x,
    118 => :opcode_ror_zpg_x,
    120 => :opcode_sei_impl,
    121 => :opcode_adc_abs_y,
    125 => :opcode_adc_abs_x,
    126 => :opcode_ror_abs_x,
    129 => :opcode_sta_x_ind,
    132 => :opcode_sty_zpg,
    133 => :opcode_sta_zpg,
    134 => :opcode_stx_zpg,
    136 => :opcode_dey_impl,
    138 => :opcode_txa_impl,
    140 => :opcode_sty_abs,
    141 => :opcode_sta_abs,
    142 => :opcode_stx_abs,
    144 => :opcode_bcc_rel,
    145 => :opcode_sta_ind_y,
    148 => :opcode_sty_zpg_x,
    149 => :opcode_sta_zpg_x,
    150 => :opcode_stx_zpg_y,
    152 => :opcode_tya_impl,
    153 => :opcode_sta_abs_y,
    154 => :opcode_txs_impl,
    157 => :opcode_sta_abs_x,
    160 => :opcode_ldy_imm,
    161 => :opcode_lda_x_ind,
    162 => :opcode_ldx_imm,
    164 => :opcode_ldy_zpg,
    165 => :opcode_lda_zpg,
    166 => :opcode_ldx_zpg,
    168 => :opcode_tay_impl,
    169 => :opcode_lda_imm,
    170 => :opcode_tax_impl,
    172 => :opcode_ldy_abs,
    173 => :opcode_lda_abs,
    174 => :opcode_ldx_abs,
    176 => :opcode_bcs_rel,
    177 => :opcode_lda_ind_y,
    180 => :opcode_ldy_zpg_x,
    181 => :opcode_lda_zpg_x,
    182 => :opcode_ldx_zpg_y,
    184 => :opcode_clv_impl,
    185 => :opcode_lda_abs_y,
    186 => :opcode_tsx_impl,
    188 => :opcode_ldy_abs_x,
    189 => :opcode_lda_abs_x,
    190 => :opcode_ldx_abs_y,
    192 => :opcode_cpy_imm,
    193 => :opcode_cmp_x_ind,
    196 => :opcode_cpy_zpg,
    197 => :opcode_cmp_zpg,
    198 => :opcode_dec_zpg,
    200 => :opcode_iny_impl,
    201 => :opcode_cmp_imm,
    202 => :opcode_dex_impl,
    204 => :opcode_cpy_abs,
    205 => :opcode_cmp_abs,
    206 => :opcode_dec_abs,
    208 => :opcode_bne_rel,
    209 => :opcode_cmp_ind_y,
    213 => :opcode_cmp_zpg_x,
    214 => :opcode_dec_zpg_x,
    216 => :opcode_cld_impl,
    217 => :opcode_cmp_abs_y,
    221 => :opcode_cmp_abs_x,
    222 => :opcode_dec_abs_x,
    224 => :opcode_cpx_imm,
    225 => :opcode_sbc_x_ind,
    228 => :opcode_cpx_zpg,
    229 => :opcode_sbc_zpg,
    230 => :opcode_inc_zpg,
    232 => :opcode_inx_impl,
    233 => :opcode_sbc_imm,
    234 => :opcode_nop_impl,
    236 => :opcode_cpx_abs,
    237 => :opcode_sbc_abs,
    238 => :opcode_inc_abs,
    240 => :opcode_beq_rel,
    241 => :opcode_sbc_ind_y,
    245 => :opcode_sbc_zpg_x,
    246 => :opcode_inc_zpg_x,
    248 => :opcode_sed_impl,
    249 => :opcode_sbc_abs_y,
    253 => :opcode_sbc_abs_x,
    254 => :opcode_inc_abs_x,
  }
  I__OPCODE = OPCODE.invert
  def initialize(_io, _parent = nil, _root = self)
    super(_io, _parent, _root)
    _read
  end

  def _read
    @operations = []
    i = 0
    while not @_io.eof?
      @operations << Operation.new(@_io, self, @_root)
      i += 1
    end
    self
  end
  class Operation < Kaitai::Struct::Struct
    def initialize(_io, _parent = nil, _root = self)
      super(_io, _parent, _root)
      _read
    end

    def _read
      @code = Kaitai::Struct::Stream::resolve_enum(OPCODE, @_io.read_u1)
      case code
      when :opcode_lsr_abs_x
        @args = @_io.read_u2le
      when :opcode_and_abs
        @args = @_io.read_u2le
      when :opcode_bit_zpg
        @args = @_io.read_u1
      when :opcode_asl_zpg
        @args = @_io.read_u1
      when :opcode_ror_abs_x
        @args = @_io.read_u2le
      when :opcode_sty_abs
        @args = @_io.read_u2le
      when :opcode_ora_zpg
        @args = @_io.read_u1
      when :opcode_eor_zpg_x
        @args = @_io.read_u1
      when :opcode_eor_abs
        @args = @_io.read_u2le
      when :opcode_eor_zpg
        @args = @_io.read_u1
      when :opcode_ora_abs_x
        @args = @_io.read_u2le
      when :opcode_adc_abs_y
        @args = @_io.read_u2le
      when :opcode_sty_zpg
        @args = @_io.read_u1
      when :opcode_eor_ind_y
        @args = @_io.read_u1
      when :opcode_rol_abs
        @args = @_io.read_u2le
      when :opcode_eor_imm
        @args = @_io.read_u1
      when :opcode_bmi_rel
        @args = @_io.read_s1
      when :opcode_inc_abs_x
        @args = @_io.read_u2le
      when :opcode_cpy_zpg
        @args = @_io.read_u1
      when :opcode_jsr_abs
        @args = @_io.read_u2le
      when :opcode_and_abs_y
        @args = @_io.read_u2le
      when :opcode_cmp_zpg
        @args = @_io.read_u1
      when :opcode_sbc_ind_y
        @args = @_io.read_u1
      when :opcode_and_x_ind
        @args = @_io.read_u1
      when :opcode_bvc_rel
        @args = @_io.read_s1
      when :opcode_ora_x_ind
        @args = @_io.read_u1
      when :opcode_ora_abs_y
        @args = @_io.read_u2le
      when :opcode_lsr_abs
        @args = @_io.read_u2le
      when :opcode_ldx_zpg_y
        @args = @_io.read_u1
      when :opcode_rol_abs_x
        @args = @_io.read_u2le
      when :opcode_adc_abs
        @args = @_io.read_u2le
      when :opcode_sty_zpg_x
        @args = @_io.read_u1
      when :opcode_ora_zpg_x
        @args = @_io.read_u1
      when :opcode_ldy_abs_x
        @args = @_io.read_u2le
      when :opcode_adc_imm
        @args = @_io.read_u1
      when :opcode_sbc_zpg
        @args = @_io.read_u1
      when :opcode_ldx_imm
        @args = @_io.read_u1
      when :opcode_beq_rel
        @args = @_io.read_s1
      when :opcode_sbc_abs_x
        @args = @_io.read_u2le
      when :opcode_ldx_abs_y
        @args = @_io.read_u2le
      when :opcode_ora_imm
        @args = @_io.read_u1
      when :opcode_bcs_rel
        @args = @_io.read_s1
      when :opcode_sbc_zpg_x
        @args = @_io.read_u1
      when :opcode_sta_zpg
        @args = @_io.read_u1
      when :opcode_bcc_rel
        @args = @_io.read_s1
      when :opcode_and_imm
        @args = @_io.read_u1
      when :opcode_ldy_zpg
        @args = @_io.read_u1
      when :opcode_adc_zpg
        @args = @_io.read_u1
      when :opcode_bne_rel
        @args = @_io.read_s1
      when :opcode_eor_abs_y
        @args = @_io.read_u2le
      when :opcode_cpy_abs
        @args = @_io.read_u2le
      when :opcode_stx_abs
        @args = @_io.read_u2le
      when :opcode_ldy_imm
        @args = @_io.read_u1
      when :opcode_lda_zpg_x
        @args = @_io.read_u1
      when :opcode_cmp_abs_y
        @args = @_io.read_u2le
      when :opcode_lsr_zpg_x
        @args = @_io.read_u1
      when :opcode_eor_abs_x
        @args = @_io.read_u2le
      when :opcode_cmp_abs_x
        @args = @_io.read_u2le
      when :opcode_inc_abs
        @args = @_io.read_u2le
      when :opcode_sta_zpg_x
        @args = @_io.read_u1
      when :opcode_sta_x_ind
        @args = @_io.read_u1
      when :opcode_cmp_imm
        @args = @_io.read_u1
      when :opcode_eor_x_ind
        @args = @_io.read_u1
      when :opcode_cmp_ind_y
        @args = @_io.read_u1
      when :opcode_cmp_x_ind
        @args = @_io.read_u1
      when :opcode_asl_abs_x
        @args = @_io.read_u2le
      when :opcode_dec_zpg_x
        @args = @_io.read_u1
      when :opcode_sbc_abs_y
        @args = @_io.read_u2le
      when :opcode_stx_zpg
        @args = @_io.read_u1
      when :opcode_lda_abs_x
        @args = @_io.read_u2le
      when :opcode_and_zpg
        @args = @_io.read_u1
      when :opcode_sbc_x_ind
        @args = @_io.read_u1
      when :opcode_lda_zpg
        @args = @_io.read_u1
      when :opcode_jmp_ind
        @args = @_io.read_u2le
      when :opcode_sta_abs_y
        @args = @_io.read_u2le
      when :opcode_asl_abs
        @args = @_io.read_u2le
      when :opcode_cmp_zpg_x
        @args = @_io.read_u1
      when :opcode_ldx_abs
        @args = @_io.read_u2le
      when :opcode_adc_zpg_x
        @args = @_io.read_u1
      when :opcode_ror_zpg_x
        @args = @_io.read_u1
      when :opcode_and_abs_x
        @args = @_io.read_u2le
      when :opcode_sta_abs
        @args = @_io.read_u2le
      when :opcode_adc_abs_x
        @args = @_io.read_u2le
      when :opcode_bit_abs
        @args = @_io.read_u2le
      when :opcode_dec_abs_x
        @args = @_io.read_u2le
      when :opcode_stx_zpg_y
        @args = @_io.read_u1
      when :opcode_lda_abs_y
        @args = @_io.read_u2le
      when :opcode_lda_x_ind
        @args = @_io.read_u1
      when :opcode_cpy_imm
        @args = @_io.read_u1
      when :opcode_ora_ind_y
        @args = @_io.read_u1
      when :opcode_asl_zpg_x
        @args = @_io.read_u1
      when :opcode_and_ind_y
        @args = @_io.read_u1
      when :opcode_sta_ind_y
        @args = @_io.read_u1
      when :opcode_ror_abs
        @args = @_io.read_u2le
      when :opcode_ldx_zpg
        @args = @_io.read_u1
      when :opcode_and_zpg_x
        @args = @_io.read_u1
      when :opcode_cpx_imm
        @args = @_io.read_u1
      when :opcode_bvs_rel
        @args = @_io.read_s1
      when :opcode_ldy_abs
        @args = @_io.read_u2le
      when :opcode_inc_zpg
        @args = @_io.read_u1
      when :opcode_sbc_abs
        @args = @_io.read_u2le
      when :opcode_rol_zpg_x
        @args = @_io.read_u1
      when :opcode_sbc_imm
        @args = @_io.read_u1
      when :opcode_adc_x_ind
        @args = @_io.read_u1
      when :opcode_sta_abs_x
        @args = @_io.read_u2le
      when :opcode_cpx_abs
        @args = @_io.read_u2le
      when :opcode_cmp_abs
        @args = @_io.read_u2le
      when :opcode_lda_abs
        @args = @_io.read_u2le
      when :opcode_rol_zpg
        @args = @_io.read_u1
      when :opcode_inc_zpg_x
        @args = @_io.read_u1
      when :opcode_lda_imm
        @args = @_io.read_u1
      when :opcode_dec_zpg
        @args = @_io.read_u1
      when :opcode_adc_ind_y
        @args = @_io.read_u1
      when :opcode_lda_ind_y
        @args = @_io.read_u1
      when :opcode_bpl_rel
        @args = @_io.read_s1
      when :opcode_lsr_zpg
        @args = @_io.read_u1
      when :opcode_jmp_abs
        @args = @_io.read_u2le
      when :opcode_dec_abs
        @args = @_io.read_u2le
      when :opcode_ora_abs
        @args = @_io.read_u2le
      when :opcode_ror_zpg
        @args = @_io.read_u1
      when :opcode_ldy_zpg_x
        @args = @_io.read_u1
      when :opcode_cpx_zpg
        @args = @_io.read_u1
      end
      self
    end
    attr_reader :code
    attr_reader :args
  end
  attr_reader :operations
end