Class: Wilson::Assembler

Inherits:
Object show all
Defined in:
lib/wilson.rb

Overview

Assembler parses the NASM documentation and creates Command objects for it

Constant Summary collapse

@@default = 
nil

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Assembler

Returns a new instance of Assembler.



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# File 'lib/wilson.rb', line 97

def initialize
  self.commands = []
end

Instance Attribute Details

#commands ⇒ Object

Returns the value of attribute commands.



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# File 'lib/wilson.rb', line 41

def commands
  @commands
end

Class Method Details

.commands ⇒ Object 



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# File 'lib/wilson.rb', line 89

def self.commands
  self.default.commands
end

.default ⇒ Object 



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# File 'lib/wilson.rb', line 81

def self.default
  @@default ||= self.new.parse
end

.default=(o) ⇒ Object 



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# File 'lib/wilson.rb', line 85

def self.default= o
  @@default = o
end

.nasm ⇒ Object 



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# File 'lib/wilson.rb', line 75

def self.nasm
  File.read(__FILE__).split(/__END__/).last
end

.nasm_fixes ⇒ Object 



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# File 'lib/wilson.rb', line 43

def self.nasm_fixes
  # TODO: extend parser to split /[,:]/ and remove some of these
  '
   CALL imm,imm16 ; o16 9A iw iw         [8086]
   CALL imm,imm32 ; o32 9A id iw         [386]
   CALLFAR mem16  ; o16 FF /3            [8086]
   CALLFAR mem32  ; o32 FF /3            [386]

   Jcc imm        ; 0F 80+cc rw/rd       [386]

   JMP imm,imm16  ; o16 EA iw iw         [8086]
   JMP imm,imm32  ; o32 EA id iw         [386]
   JMP imm16      ; E9 rw/rd             [8086]
   JMP imm32      ; E9 rw/rd             [8086]
   JMP imm8       ; EB rb                [8086]
   JMPFAR mem16   ; o16 FF /5            [8086]
   JMPFAR mem32   ; o32 FF /5            [386]

   FADDTO fpureg  ; DC C0+r              [8086,FPU]
   FDIVTO fpureg  ; DC F8+r              [8086,FPU]
   FDIVRTO fpureg ; DC F0+r              [8086,FPU]
   FMULTO fpureg  ; DC C8+r              [8086,FPU]
   FSUBTO fpureg  ; DC E8+r              [8086,FPU]
   FSUBRTO fpureg ; DC E0+r              [8086,FPU]

   CMP r/m16,imm8 ; o16 83 /7 ib         [8086]
   CMP r/m32,imm8 ; o32 83 /7 ib         [386]
   SAR r/m16,1    ; o16 D1 /7            [8086]
   SAR r/m32,1    ; o32 D1 /7            [386]
  '
end

.parse ⇒ Object 



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# File 'lib/wilson.rb', line 93

def self.parse
  self.new.parse
end

Instance Method Details

#add_command(command) ⇒ Object 



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# File 'lib/wilson.rb', line 141

def add_command command
  return self.add_conditional_commands(command) if command.opcode =~ /cc$/i
  self.commands << command
  self.expand_parameters command
end

#add_conditional_commands(prototype) ⇒ Object 



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# File 'lib/wilson.rb', line 119

def add_conditional_commands prototype
  prototype.opcode = prototype.opcode[0..-3]

  self.conditionals.each do |conditional, value|
    command = prototype.dup
    command.opcode += conditional

    command.opcodes.each_with_index do |op, index|
      command.opcodes[index] = ($1.hex+value).to_s(16) if op =~ /(.*)\+cc$/
    end

    self.add_command command
  end
end

#conditionals ⇒ Object 



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# File 'lib/wilson.rb', line 147

def conditionals
  @conditionals ||= {
    'O'   =>  0, 'NO' =>  1, 'B'  =>  2, 'C'   =>  2, 'NAE' =>  2,
    'AE'  =>  3, 'NB' =>  3, 'NC' =>  3, 'E'   =>  4, 'Z'   =>  4,
    'NE'  =>  5, 'NZ' =>  5, 'BE' =>  6, 'NA'  =>  6, 'A'   =>  7,
    'NBE' =>  7, 'S'  =>  8, 'NS' =>  9, 'P'   => 10, 'PE'  => 10,
    'NP'  => 11, 'PO' => 11, 'L'  => 12, 'NGE' => 12, 'GE'  => 13,
    'NL'  => 13, 'LE' => 14, 'NG' => 14, 'G'   => 15, 'NLE' => 15,
  }
end

#expand_parameters(command) ⇒ Object 



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# File 'lib/wilson.rb', line 101

def expand_parameters command
  command.parameters.each_with_index do |parameter, index|
    if String === parameter && parameter =~ /^r\/m(\d+)/ then
      bits = $1.to_i
      newCommand = command.dup
      commands << newCommand
      case bits
      when 8, 16, 32 then
        command.parameters[index]    = MemoryRegister.new bits
        newCommand.parameters[index] = Address.new false, bits
      when 64 then
        command.parameters[index]    = MMXRegister.new bits
        newCommand.parameters[index] = Address.new false, bits
      end
    end
  end
end

#parse ⇒ Object 



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# File 'lib/wilson.rb', line 175

def parse
  (self.class.nasm + self.class.nasm_fixes).each_line do |line|
    self.process_line line.strip.sub(/^# /, '')
  end

  self
end

#parse_command(line) ⇒ Object 



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# File 'lib/wilson.rb', line 158

def parse_command line
  if line =~ /^(\w+)\s+([^;]*)\s+;\s+([^\[]+)\s+\[([\w,]+)\]/ then
    name, params, ops, procs = $1, $2, $3, $4

    command            = Command.new
    command.opcode     = name
    command.opcodes    = ops.split
    command.processors = procs.split(/,/)

    command.initialize_parameters params.strip

    self.add_command command
  else
    raise "unparsed: #{line}"
  end
end

#process_line(line) ⇒ Object

TODO: remove



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# File 'lib/wilson.rb', line 134

def process_line line # TODO: remove
  return if line.empty?
  return unless line =~ /^[A-Z].+;.*\[/

  self.parse_command line
end