Hi, I put together a python script that works with simulavr to simulate a serial port that one can use to interact with the simulated machine's UART. The script also supports creating of VCD trace files for analyzing pin changes and other events.
This is useful for AVR programs that communication over a serial port with a host system. For example, if one normally uses a host program to communicate with a real AVR device - such as: $ cu -l /dev/ttyS0 -s 9600 then a simulation could be done with something like: $ avrserial.py program.elf -b 9600 -p /tmp/pseudoserial & $ cu -l /tmp/pseudoserial -s 9600 The avrserial.py script creates a pseudo-tty device that most serial terminal programs can use instead of a real serial device. The created pseudo-serial is forwarded to the AVR simulation. It took some time to get the python parameters for this correct, so I figured I would post the script in case others find it useful. I posted an earlier version of the script last year: http://lists.gnu.org/archive/html/simulavr-devel/2014-08/msg00000.html The script supports a number of options - run "avrserial.py -h" to see them. The script uses the simulavr python library, so simulavr must be compiled with python support and the python module must be in the python path. I ususally run the script with something like: $ PYTHONPATH=/path/to/simulavr/src ./avrserial.py -h Please CC me on any replies. -Kevin =========================== avrserial.py =========================== #!/usr/bin/env python # Script to interact with simulavr by simulating a serial port. # # Copyright (C) 2015 Kevin O'Connor <ke...@koconnor.net> # # This file may be distributed under the terms of the GNU GPLv3 license. import sys, optparse, os, pty, select, fcntl, termios, traceback import pysimulavr SERIALBITS = 10 # 8N1 = 1 start, 8 data, 1 stop # Class to read serial data from AVR serial transmit pin. class SerialRxPin(pysimulavr.PySimulationMember, pysimulavr.Pin): def __init__(self, baud): pysimulavr.Pin.__init__(self) pysimulavr.PySimulationMember.__init__(self) self.sc = pysimulavr.SystemClock.Instance() self.delay = 10**9 / baud self.current = 0 self.pos = -1 self.queue = "" def SetInState(self, pin): pysimulavr.Pin.SetInState(self, pin) self.state = pin.outState if self.pos < 0 and pin.outState == pin.LOW: self.pos = 0 self.sc.Add(self) def DoStep(self, trueHwStep): ishigh = self.state == self.HIGH self.current |= ishigh << self.pos self.pos += 1 if self.pos == 1: return int(self.delay * 1.5) if self.pos >= SERIALBITS: self.queue += chr((self.current >> 1) & 0xff) self.pos = -1 self.current = 0 return -1 return self.delay def popChars(self): d = self.queue self.queue = "" return d # Class to send serial data to AVR serial receive pin. class SerialTxPin(pysimulavr.PySimulationMember, pysimulavr.Pin): def __init__(self, baud): pysimulavr.Pin.__init__(self) pysimulavr.PySimulationMember.__init__(self) self.SetPin('H') self.sc = pysimulavr.SystemClock.Instance() self.delay = 10**9 / baud self.current = 0 self.pos = 0 self.queue = "" def DoStep(self, trueHwStep): if not self.pos: if not self.queue: return -1 self.current = (ord(self.queue[0]) << 1) | 0x200 self.queue = self.queue[1:] newstate = 'L' if self.current & (1 << self.pos): newstate = 'H' self.SetPin(newstate) self.pos += 1 if self.pos >= SERIALBITS: self.pos = 0 return self.delay def pushChars(self, c): queueEmpty = not self.queue self.queue += c if queueEmpty: self.sc.Add(self) # Support for creating VCD trace files class Tracing: def __init__(self, filename, signals): self.filename = filename self.signals = signals if not signals: self.dman = None return self.dman = pysimulavr.DumpManager.Instance() self.dman.SetSingleDeviceApp() def show_help(self): ostr = pysimulavr.ostringstream() self.dman.save(ostr) sys.stdout.write(ostr.str()) sys.exit(1) def load_options(self): if self.dman is None: return if self.signals.strip() == '?': self.show_help() sigs = "\n".join(["+ " + s for s in self.signals.split(',')]) self.dman.addDumpVCD(self.filename, sigs, "ns", False, False) def start(self): if self.dman is not None: self.dman.start() def finish(self): if self.dman is not None: self.dman.stopApplication() # Support for creating a pseudo-tty for emulting a serial port def create_pty(ptyname): mfd, sfd = pty.openpty() try: os.unlink(ptyname) except os.error: pass os.symlink(os.ttyname(sfd), ptyname) fcntl.fcntl(mfd, fcntl.F_SETFL , fcntl.fcntl(mfd, fcntl.F_GETFL) | os.O_NONBLOCK) old = termios.tcgetattr(mfd) old[3] = old[3] & ~termios.ECHO termios.tcsetattr(mfd, termios.TCSADRAIN, old) return mfd def main(): usage = "%prog [options] <program.elf>" opts = optparse.OptionParser(usage) opts.add_option("-m", "--machine", type="string", dest="machine", default="atmega644", help="type of AVR machine to simulate") opts.add_option("-s", "--speed", type="int", dest="speed", default=8000000, help="machine speed") opts.add_option("-b", "--baud", type="int", dest="baud", default=38400, help="baud rate of the emulated serial port") opts.add_option("-t", "--trace", type="string", dest="trace", help="signals to trace (? for help)") opts.add_option("-p", "--port", type="string", dest="port", default="/tmp/pseudoserial", help="pseudo-tty device to create for serial port") deffile = os.path.splitext(os.path.basename(sys.argv[0]))[0] + ".vcd" opts.add_option("-f", "--tracefile", type="string", dest="tracefile", default=deffile, help="filename to write signal trace to") options, args = opts.parse_args() if len(args) != 1: opts.error("Incorrect number of arguments") elffile = args[0] proc = options.machine ptyname = options.port speed = options.speed baud = options.baud # launch simulator sc = pysimulavr.SystemClock.Instance() trace = Tracing(options.tracefile, options.trace) dev = pysimulavr.AvrFactory.instance().makeDevice(proc) dev.Load(elffile) dev.SetClockFreq(10**9 / speed) sc.Add(dev) trace.load_options() # Setup rx pin rxpin = SerialRxPin(baud) net = pysimulavr.Net() net.Add(rxpin) net.Add(dev.GetPin("D1")) # Setup tx pin txpin = SerialTxPin(baud) net2 = pysimulavr.Net() net2.Add(dev.GetPin("D0")) net2.Add(txpin) msg = "Starting AVR simulation: machine=%s speed=%d\n" % (proc, speed) msg += "Serial: port=%s baud=%d\n" % (ptyname, baud) if options.trace: msg += "Trace file: %s\n" % (options.tracefile,) sys.stdout.write(msg) sys.stdout.flush() # Create terminal device fd = create_pty(ptyname) # Run loop try: trace.start() while 1: starttime = sc.GetCurrentTime() r = sc.RunTimeRange(speed/1000) endtime = sc.GetCurrentTime() if starttime == endtime: break d = rxpin.popChars() if d: os.write(fd, d) res = select.select([fd], [], [], 0) if res[0]: d = os.read(fd, 1024) txpin.pushChars(d) trace.finish() finally: os.unlink(ptyname) if __name__ == '__main__': main() _______________________________________________ Simulavr-devel mailing list Simulavr-devel@nongnu.org https://lists.nongnu.org/mailman/listinfo/simulavr-devel
