Class: LC3

Inherits:
Object
  • Object
show all
Includes:
LC3Spec::Helpers
Defined in:
lib/lc3spec/lc3.rb

Overview

Class to provide access to LC-3 simulator instance

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from LC3Spec::Helpers

#is_absolute_path?, #normalize_to_i, #normalize_to_s

Constructor Details

#initialize ⇒ LC3

Returns a new instance of LC3.



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# File 'lib/lc3spec/lc3.rb', line 17

def initialize
  # Logging
  @logger = Logger.new(STDERR)
  if ENV['LC3DEBUG']
    @logger.level = Logger::DEBUG
  else
    @logger.level = Logger::ERROR
  end
  @logger.formatter = proc do |severity, datetime, progname, msg|
    "#{severity}: #{msg}\n"
  end

  # Registers
  @registers = {}
  [:R0, :R1, :R2, :R3, :R4, :R5, :R6, :R7, :PC, :IR, :PSR].each do |reg|
    @registers[reg] = 'x0000'
  end
  @registers[:CC] = 'ZERO'

  # Memory
  @memory = Hash.new('x0000')
  @labels = {}

  initialize_lc3sim
end

Instance Attribute Details

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/lc3spec/lc3.rb', line 15

def logger
  @logger
end

Instance Method Details

#clear_breakpoint(addr) ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 166

def clear_breakpoint(addr)
  if addr == :all
    @io.puts 'break clear all'
    return self
  end

  addr = addr.upcase.to_s if addr.respond_to? :upcase

  if @labels.include? addr
    @io.puts "break clear #{addr}"
  else
    @io.puts "break clear #{normalize_to_s(addr)}"
  end

  sleep(0.01)

  while @io.ready?
    msg = @io.readline
    parse_msg msg.strip
  end

  self
end

#clear_breakpoints ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 190

def clear_breakpoints
  clear_breakpoint :all
end

#close ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 247

def close
  @output.close
  @server.close
end

#continue ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 140

def continue
  @io.puts 'continue'

  parse_until_print_registers

  self
end

#file(filename) ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 107

def file(filename)
  @io.puts "file #{filename}"

  # Need to encounter 2 TOCODEs before we're done
  tocode_counter = 2

  while tocode_counter > 0
    msg = @io.readline

    parse_msg msg.strip

    if msg =~ /^TOCODE/
      tocode_counter -= 1
    end

    # ignore warning about no symbols
    next if msg =~ /WARNING: No symbols/

    # don't ignore other errors
    break if msg =~ /^ERR/
  end

  self
end

#get_address(label) ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 103

def get_address(label)
  @labels[label.upcase.to_s]
end

#get_memory(addr) ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 71

def get_memory(addr)
  if addr.respond_to?(:upcase)
    label_addr = get_address(addr)
    addr = label_addr unless label_addr.nil?
  end

  @memory[normalize_to_i(addr)]
end

#get_output ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 194

def get_output
  out = ''

  # There is no signal that tells the GUI that output is ready...
  # FIXME: This is a bug waiting to happen
  retries = 10
  until @output.ready?
    sleep(0.1)

    retries -= 1
    break if retries <= 0
  end

  while @output.ready?
    out << @output.readpartial(1024)
  end

  out.gsub("\n\n--- halting the LC-3 ---\n\n", '')
end

#get_register(reg) ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 43

def get_register(reg)
  reg = reg.to_s.upcase.to_sym  # Ruby 1.8 doesn't support Symbol#upcase
  @registers[reg]
end

#initialize_lc3sim ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 214

def initialize_lc3sim
  # Start lc3sim instance
  @io = IO.popen(%w(lc3sim -gui), 'r+')

  begin
    # Port for output server
    @port = (rand * 1000 + 5000).to_i

    # Start server to get output
    @server = TCPServer.new @port
  rescue Errno::EADDRINUSE
    retry
  end

  th = Thread.new do
    @output = @server.accept
  end

  # Initialize lc3sim with port number
  @io.puts @port

  # Wait for lc3sim to connect with our server
  th.join

  # Read LC-3 initialization messages (mostly loading lc3os)
  parse_until_print_registers

  # Clear all the welcome messages from lc3sim output
  while @output.ready?
    @output.readpartial 1024
  end
end

#inspect ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 252

def inspect
  registers = @registers.map { |k, v| "#{k}=#{v}" }.join(' ')

  addr_to_label = @labels.invert

  memory_header = "%18s ADDR  VALUE" % "label"
  memory = @memory.map do |addr, value|
    "%18s %s %s" % [(addr_to_label[addr] or ''),
                    normalize_to_s(addr), value]
  end.join("\n")

  #[memory_header, memory, registers].join("\n")
  registers
end

#set_breakpoint(addr) ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 148

def set_breakpoint(addr)
  addr = addr.upcase.to_s if addr.respond_to? :upcase
  if @labels.include? addr
    @io.puts "break set #{addr}"
  else
    @io.puts "break set #{normalize_to_s(addr)}"
  end

  sleep(0.01)

  while @io.ready?
    msg = @io.readline
    parse_msg msg.strip
  end

  self
end

#set_memory(addr, val) ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 80

def set_memory(addr, val)
  # addr may be memory address or label

  if addr.respond_to?(:upcase) and @labels.include?(addr.upcase.to_s)
    # Is a label
    addr = addr.upcase.to_s
  else
    # Not a label
    addr = normalize_to_s(addr)
  end

  @io.puts("memory #{addr} #{normalize_to_s(val)}")

  loop do
    msg = @io.readline
    parse_msg msg.strip

    break if msg =~ /^ERR|CODE/
  end

  self
end

#set_register(reg, val) ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 48

def set_register(reg, val)
  reg = reg.to_s.upcase # Don't use ! version because it doesn't work for symbols

  unless @registers.keys.include? reg.to_sym
    raise "Invalid register: #{reg.to_s}"
  end

  if val.nil?
    raise "Invalid register value for #{reg.to_s}: #{val}"
  end

  @io.puts "register #{reg.to_s} #{normalize_to_s(val)}"

  loop do
    msg = @io.readline
    parse_msg msg.strip

    break if msg =~ /^TOCODE/
  end

  self
end

#step ⇒ Object 



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# File 'lib/lc3spec/lc3.rb', line 132

def step
  @io.puts 'step'

  parse_until_print_registers

  self
end