blob: b66b5353bb588f56c4d9ccd52d3383bbc0826b0d [file] [log] [blame]
#! /usr/bin/env python3
# Copyright (c) 2017 Linaro Limited.
#
# SPDX-License-Identifier: Apache-2.0
"""Zephyr binary runner core interfaces
This provides the core ZephyrBinaryRunner class meant for public use,
as well as some other helpers for concrete runner classes.
"""
import abc
import os
import platform
import pprint
import shlex
import signal
import subprocess
import sys
def get_env_or_bail(env_var):
'''Get an environment variable, or raise an error.
In case of KeyError, an error message is printed, along with the
environment, and the exception is re-raised.
'''
try:
return os.environ[env_var]
except KeyError:
print('Variable {} not in environment:'.format(
env_var), file=sys.stderr)
pprint.pprint(dict(os.environ), stream=sys.stderr)
raise
def get_env_bool_or(env_var, default_value):
'''Get an environment variable as a boolean, or return a default value.
Get an environment variable, interpret it as a base ten
integer, and convert that to a boolean.
In case the environment variable is not defined, return default_value.
'''
try:
return bool(int(os.environ[env_var]))
except KeyError:
return default_value
def get_env_strip_or(env_var, to_strip, default_value):
'''Get and clean up an environment variable, or return a default value.
Get the value of env_var from the environment. If it is
defined, return that value with to_strip stripped off. If it
is undefined, return default_value (without any stripping).
'''
value = os.environ.get(env_var, None)
if value is not None:
return value.strip(to_strip)
else:
return default_value
def quote_sh_list(cmd):
'''Transform a command from list into shell string form.'''
fmt = ' '.join('{}' for _ in cmd)
args = [shlex.quote(s) for s in cmd]
return fmt.format(*args)
MAX_PORT = 49151
class NetworkPortHelper:
'''Helper class for dealing with local IP network ports.'''
def get_unused_ports(self, starting_from):
'''Find unused network ports, starting at given values.
starting_from is an iterable of ports the caller would like to use.
The return value is an iterable of ports, in the same order, using
the given values if they were unused, or the next sequentially
available unused port otherwise.
Ports may be bound between this call's check and actual usage, so
callers still need to handle errors involving returned ports.'''
start = list(starting_from)
used = self._used_now()
ret = []
for desired in start:
port = desired
while port in used:
port += 1
if port > MAX_PORT:
msg = "ports above {} are in use"
raise ValueError(msg.format(desired))
used.add(port)
ret.append(port)
return ret
def _used_now(self):
handlers = {
'Windows': self._used_now_windows,
'Linux': self._used_now_linux,
'Darwin': self._used_now_darwin,
}
handler = handlers[platform.system()]
return handler()
def _used_now_windows(self):
cmd = ['netstat', '-a', '-n', '-p', 'tcp']
return self._parser_windows(cmd)
def _used_now_linux(self):
cmd = ['ss', '-a', '-n', '-t']
return self._parser_linux(cmd)
def _used_now_darwin(self):
cmd = ['netstat', '-a', '-n', '-p', 'tcp']
return self._parser_darwin(cmd)
def _parser_windows(self, cmd):
out = subprocess.check_output(cmd).split(b'\r\n')
used_bytes = [x.split()[1].rsplit(b':', 1)[1] for x in out
if x.startswith(b' TCP')]
return {int(b) for b in used_bytes}
def _parser_linux(self, cmd):
out = subprocess.check_output(cmd).splitlines()[1:]
used_bytes = [s.split()[3].rsplit(b':', 1)[1] for s in out]
return {int(b) for b in used_bytes}
def _parser_darwin(self, cmd):
out = subprocess.check_output(cmd).split(b'\n')
used_bytes = [x.split()[3].rsplit(b':', 1)[1] for x in out
if x.startswith(b'tcp')]
return {int(b) for b in used_bytes}
class ZephyrBinaryRunner(abc.ABC):
'''Abstract superclass for binary runners (flashers, debuggers).
With some exceptions, boards supported by Zephyr must provide
generic means to be flashed (have a Zephyr firmware binary
permanently installed on the device for running) and debugged
(have a breakpoint debugger and program loader on a host
workstation attached to a running target). This is supported by
three top-level commands managed by the Zephyr build system:
- 'flash': flash a previously configured binary to the board,
start execution on the target, then return.
- 'debug': connect to the board via a debugging protocol, then
drop the user into a debugger interface with symbol tables
loaded from the current binary, and block until it exits.
- 'debugserver': connect via a board-specific debugging protocol,
then reset and halt the target. Ensure the user is now able to
connect to a debug server with symbol tables loaded from the
binary.
Runner functionality relies on a variety of target-specific tools
and configuration values, the user interface to which is
abstracted by this class. Each runner subclass should take any
values it needs to execute one of these commands in its
constructor. The actual command execution is handled in the run()
method.
This functionality has replaced the legacy Zephyr runners,
which were shell scripts.
At present, the Zephyr build system uses a variety of
tool-specific environment variables to control runner behavior.
To support a transition to ZephyrBinaryRunner and subclasses, this
class provides a create_for_shell_script() static factory method.
This method iterates over ZephyrBinaryRunner subclasses,
determines which (if any) can provide equivalent functionality to
the old shell-based runner, and returns a subclass instance with its
configuration determined from the environment.
To support this, subclasess currently must provide a pair of
static methods, replaces_shell_script() and create_from_env(). The
first allows the runner subclass to declare which commands and
scripts it can replace. The second is called by
create_for_shell_script() to create a concrete runner instance.
The environment-based factories are for legacy use *only*; the
user must be able to construct and use a runner using only the
constructor and run() method.'''
def __init__(self, debug=False):
self.debug = debug
@staticmethod
def create_for_shell_script(shell_script, command, debug):
'''Factory for using as a drop-in replacement to a shell script.
Command is one of 'flash', 'debug', 'debugserver'.
Get runner instance to use in place of shell_script, deriving
configuration from the environment.'''
for sub_cls in ZephyrBinaryRunner.__subclasses__():
if sub_cls.replaces_shell_script(shell_script, command):
return sub_cls.create_from_env(command, debug)
raise ValueError('cannot implement script {} command {}'.format(
shell_script, command))
@staticmethod
@abc.abstractmethod
def replaces_shell_script(shell_script, command):
'''Check if this class replaces shell_script for the given command.'''
@staticmethod
@abc.abstractmethod
def create_from_env(command, debug):
'''Create new flasher instance from environment variables.
This class must be able to replace the current shell script
(FLASH_SCRIPT or DEBUG_SCRIPT, depending on command). The
environment variables expected by that script are used to build
the flasher in a backwards-compatible manner.'''
def run(self, command, **kwargs):
'''Runs command ('flash', 'debug', 'debugserver').
This is the main entry point to this runner.'''
self.do_run(command, **kwargs)
@abc.abstractmethod
def do_run(self, command, **kwargs):
'''Concrete runner; run() delegates to this. Implement in subclasses.
In case of an unsupported command, raise a ValueError.'''
def run_server_and_client(self, server, client):
'''Run a server that ignores SIGINT, and a client that handles it.
This routine portably:
- creates a Popen object for the `server' command which ignores SIGINT
- runs `client' in a subprocess while temporarily ignoring SIGINT
- cleans up the server after the client exits.
It's useful to e.g. open a GDB server and client.'''
server_proc = self.popen_ignore_int(server)
previous = signal.signal(signal.SIGINT, signal.SIG_IGN)
try:
self.check_call(client)
finally:
signal.signal(signal.SIGINT, previous)
server_proc.terminate()
server_proc.wait()
def check_call(self, cmd):
'''Subclass subprocess.check_call() wrapper.
Subclasses should use this command to run command in a
subprocess and check that it executed correctly, rather than
using subprocess directly, to keep accurate debug logs.
'''
if self.debug:
print(quote_sh_list(cmd))
subprocess.check_call(cmd)
def check_output(self, cmd):
'''Subclass subprocess.check_output() wrapper.
Subclasses should use this command to run command in a
subprocess and check that it executed correctly, rather than
using subprocess directly, to keep accurate debug logs.
'''
if self.debug:
print(quote_sh_list(cmd))
return subprocess.check_output(cmd)
def popen_ignore_int(self, cmd):
'''Spawn a child command, ensuring it ignores SIGINT.
The returned subprocess.Popen object must be manually terminated.'''
cflags = 0
preexec = None
system = platform.system()
if system == 'Windows':
cflags |= subprocess.CREATE_NEW_PROCESS_GROUP
elif system in {'Linux', 'Darwin'}:
preexec = os.setsid
if self.debug:
print(quote_sh_list(cmd))
return subprocess.Popen(cmd, creationflags=cflags, preexec_fn=preexec)