#!/usr/bin/env python3

import argparse
import base64
import copy
import datetime
import glob
import imp
import json
import os
import re
import shlex
import shutil
import signal
import stat
import subprocess
import sys
import time
import urllib
import urllib.request

this = sys.modules[__name__]
root_dir = os.path.dirname(os.path.abspath(__file__))
data_dir = os.path.join(root_dir, 'data')
p9_dir = os.path.join(data_dir, '9p')
gem5_non_default_src_root_dir = os.path.join(data_dir, 'gem5')
out_dir = os.path.join(root_dir, 'out')
bench_boot = os.path.join(out_dir, 'bench-boot.txt')
packages_dir = os.path.join(root_dir, 'packages')
kernel_modules_src_dir = os.path.join(this.packages_dir, 'kernel_modules')
submodules_dir = os.path.join(root_dir, 'submodules')
buildroot_src_dir = os.path.join(submodules_dir, 'buildroot')
crosstool_ng_src_dir = os.path.join(submodules_dir, 'crosstool-ng')
linux_src_dir = os.path.join(submodules_dir, 'linux')
extract_vmlinux = os.path.join(linux_src_dir, 'scripts', 'extract-vmlinux')
qemu_src_dir = os.path.join(submodules_dir, 'qemu')
parsec_benchmark_src_dir = os.path.join(submodules_dir, 'parsec-benchmark')
ccache_dir = os.path.join('/usr', 'lib', 'ccache')
arch_map = {
    'a': 'arm',
    'A': 'aarch64',
    'x': 'x86_64',
}
arches = [arch_map[k] for k in arch_map]
gem5_cpt_prefix = '^cpt\.'
sha = subprocess.check_output(['git', '-C', root_dir, 'log', '-1', '--format=%H']).decode().rstrip()
release_dir = os.path.join(this.out_dir, 'release')
release_zip_file = os.path.join(this.release_dir, 'lkmc-{}.zip'.format(this.sha))
github_repo_id = 'cirosantilli/linux-kernel-module-cheat'
config_file = os.path.join(data_dir, 'config')
if os.path.exists(config_file):
    config = imp.load_source('config', config_file)
    configs = {x:getattr(config, x) for x in dir(config) if not x.startswith('__')}

def add_build_arguments(parser):
    parser.add_argument(
        '--clean',
        help='Clean the build instead of building.',
        action='store_true',
    )

def base64_encode(string):
    return base64.b64encode(string.encode()).decode()

def gem_list_checkpoint_dirs():
    '''
    List checkpoint directory, oldest first.
    '''
    global this
    prefix_re = re.compile(this.gem5_cpt_prefix)
    files = list(filter(lambda x: os.path.isdir(os.path.join(this.m5out_dir, x)) and prefix_re.search(x), os.listdir(this.m5out_dir)))
    files.sort(key=lambda x: os.path.getmtime(os.path.join(this.m5out_dir, x)))
    return files

def get_argparse(default_args=None, argparse_args=None):
    '''
    Return an argument parser with common arguments set.

    :type default_args: Dict[str,str]
    :type argparse_args: Dict
    '''
    global this
    if default_args is None:
        default_args = {}
    if argparse_args is None:
        argparse_args = {}
    arch_choices = []
    for key in this.arch_map:
        arch_choices.append(key)
        arch_choices.append(this.arch_map[key])
    default_build_id = 'default'
    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawTextHelpFormatter,
        **argparse_args
    )
    parser.add_argument(
        '-a', '--arch', choices=arch_choices, default='x86_64',
        help='CPU architecture. Default: %(default)s'
    )
    parser.add_argument(
        '--baremetal',
        help='Use Baremetal examples instead of Linux kernel ones'
    )
    parser.add_argument(
        '--crosstool-ng-build-id', default=default_build_id,
        help='Crosstool-NG build ID. Allows you to keep multiple separate crosstool-NG builds. Default: %(default)s'
    )
    parser.add_argument(
        '-g', '--gem5', default=False, action='store_true',
        help='Use gem5 instead of QEMU'
    )
    parser.add_argument(
        '-L', '--linux-build-id', default=default_build_id,
        help='Linux build ID. Allows you to keep multiple separate Linux builds. Default: %(default)s'
    )
    parser.add_argument(
        '--machine',
        help='''Machine type.
QEMU default: virt
gem5 default: VExpress_GEM5_V1
See the documentation for other values known to work.
'''
    )
    parser.add_argument(
        '-M', '--gem5-build-id', default=default_build_id,
        help='gem5 build ID. Allows you to keep multiple separate gem5 builds. Default: %(default)s'
    )
    parser.add_argument(
        '-N', '--gem5-worktree',
        help='''\
gem5 git worktree to use for build and Python scripts at runtime. Automatically
create a new git worktree with the given id if one does not exist. If not
given, just use the submodule source.
'''
    )
    parser.add_argument(
        '--gem5-source',
        help='''\
Use the given directory as the gem5 source tree. Ignore `--gem5-worktree`.
'''
    )
    parser.add_argument(
        '-n', '--run-id', default='0',
        help='''\
ID for run outputs such as gem5's m5out. Allows you to do multiple runs,
and then inspect separate outputs later in different output directories.
Default: %(default)s
'''
    )
    parser.add_argument(
        '-P', '--prebuilt', default=False, action='store_true',
        help='''\
Use prebuilt packaged host utilities as much as possible instead
of the ones we built ourselves. Saves build time, but decreases
the likelihood of compatibility.
'''
    )
    parser.add_argument(
        '--port-offset', type=int,
        help='''\
Increase the ports to be used such as for GDB by an offset to run multiple
instances in parallel.
Default: the run ID (-n) if that is an integer, otherwise 0.
'''
    )
    parser.add_argument(
        '-Q', '--qemu-build-id', default=default_build_id,
        help='QEMU build ID. Allows you to keep multiple separate QEMU builds. Default: %(default)s'
    )
    parser.add_argument(
        '--buildroot-build-id',
        default=default_build_id,
        help='Buildroot build ID. Allows you to keep multiple separate gem5 builds. Default: %(default)s'
    )
    parser.add_argument(
        '-t', '--gem5-build-type', default='opt',
        help='gem5 build type, most often used for "debug" builds. Default: %(default)s'
    )
    if hasattr(this, 'configs'):
        defaults = this.configs.copy()
    else:
        defaults = {}
    defaults.update(default_args)
    # A bit ugly as it actually changes the defaults shown on --help, but we can't do any better
    # because it is impossible to check if arguments were given or not...
    # - https://stackoverflow.com/questions/30487767/check-if-argparse-optional-argument-is-set-or-not
    # - https://stackoverflow.com/questions/3609852/which-is-the-best-way-to-allow-configuration-options-be-overridden-at-the-comman
    parser.set_defaults(**defaults)
    return parser

def get_elf_entry(elf_file_path):
    global this
    readelf_header = subprocess.check_output([
        this.get_toolchain_tool('readelf'),
        '-h',
        elf_file_path
    ])
    for line in readelf_header.decode().split('\n'):
        split = line.split()
        if line.startswith('  Entry point address:'):
            addr = line.split()[-1]
            break
    return int(addr, 0)

def get_stats(stat_re=None, stats_file=None):
    global this
    if stat_re is None:
        stat_re = '^system.cpu[0-9]*.numCycles$'
    if stats_file is None:
        stats_file = this.stats_file
    stat_re = re.compile(stat_re)
    ret = []
    with open(stats_file, 'r') as statfile:
        for line in statfile:
            if line[0] != '-':
                cols = line.split()
                if len(cols) > 1 and stat_re.search(cols[0]):
                    ret.append(cols[1])
    return ret

def get_toolchain_tool(tool):
    global this
    if this.baremetal is None:
        return glob.glob(os.path.join(this.host_bin_dir, '*-buildroot-*-{}'.format(tool)))[0]
    else:
        return os.path.join(this.crosstool_ng_bin_dir, '{}-{}'.format(this.crosstool_ng_prefix, tool))

def github_make_request(
        authenticate=False,
        data=None,
        extra_headers=None,
        path='',
        subdomain='api',
        url_params=None,
        **extra_request_args
    ):
    global this
    if extra_headers is None:
        extra_headers = {}
    headers = {'Accept': 'application/vnd.github.v3+json'}
    headers.update(extra_headers)
    if authenticate:
        headers['Authorization'] = 'token ' + os.environ['LKMC_GITHUB_TOKEN']
    if url_params is not None:
        path += '?' + urllib.parse.urlencode(url_params)
    request = urllib.request.Request(
        'https://' + subdomain + '.github.com/repos/' + github_repo_id + path,
        headers=headers,
        data=data,
        **extra_request_args
    )
    response_body = urllib.request.urlopen(request).read().decode()
    if response_body:
        _json = json.loads(response_body)
    else:
        _json = {}
    return _json

def log_error(msg):
    print('error: {}'.format(msg), file=sys.stderr)

def mkdir():
    global this
    os.makedirs(this.build_dir, exist_ok=True)
    os.makedirs(this.gem5_build_dir, exist_ok=True)
    os.makedirs(this.gem5_run_dir, exist_ok=True)
    os.makedirs(this.qemu_run_dir, exist_ok=True)
    os.makedirs(this.p9_dir, exist_ok=True)

def print_cmd(cmd, cwd, cmd_file=None, extra_env=None, extra_paths=None):
    '''
    Format a command given as a list of strings so that it can
    be viewed nicely and executed by bash directly and print it to stdout.

    Optionally save the command to cmd_file file, and add extra_env
    environment variables to the command generated.
    '''
    newline_separator = ' \\\n'
    out = []
    out.append('cd {} &&{}'.format(shlex.quote(cwd), newline_separator))
    if extra_paths is not None:
        out.append('PATH="{}:${{PATH}}"'.format(':'.join(extra_paths)) + newline_separator)
    for key in extra_env:
        out.append('{}={}'.format(shlex.quote(key), shlex.quote(extra_env[key])) + newline_separator)
    for arg in cmd:
        out.append(shlex.quote(arg) + newline_separator)
    out = '  '.join(out) + ';\n'
    print('+ ' + out, end='')
    if cmd_file is not None:
        with open(cmd_file, 'w') as f:
            f.write('#!/usr/bin/env bash\n')
            f.write(out)
        st = os.stat(cmd_file)
        os.chmod(cmd_file, st.st_mode | stat.S_IXUSR)

def print_time(ellapsed_seconds):
    hours, rem = divmod(ellapsed_seconds, 3600)
    minutes, seconds = divmod(rem, 60)
    print("time {:02}:{:02}:{:02}".format(int(hours), int(minutes), int(seconds)))

def raw_to_qcow2(prebuilt=False, reverse=False):
    global this
    if prebuilt:
        qemu_img_executable = this.qemu_img_basename
    else:
        qemu_img_executable = this.qemu_img_executable
    infmt = 'raw'
    outfmt = 'qcow2'
    infile = this.rootfs_raw_file
    outfile = this.qcow2_file
    if reverse:
        tmp = infmt
        infmt = outfmt
        outfmt = tmp
        tmp = infile
        infile = outfile
        outfile = tmp
    assert this.run_cmd([
        qemu_img_executable,
        # Prevent qemu-img from generating trace files like QEMU. Disgusting.
        '-T', 'pr_manager_run,file=/dev/null',
        'convert',
        '-f', infmt,
        '-O', outfmt,
        infile,
        outfile,
    ]) == 0

def raise_no_x86(arch):
    if (arch == 'x86_64'):
        raise Exception('x86_64 not yet supported')

def resolve_args(defaults, args, extra_args):
    if extra_args is None:
        extra_args = {}
    argcopy = copy.copy(args)
    argcopy.__dict__ = dict(list(defaults.items()) + list(argcopy.__dict__.items()) + list(extra_args.items()))
    return argcopy

def rmrf(path):
    if os.path.exists(path):
        shutil.rmtree(path)

def run_cmd(
        cmd,
        cmd_file=None,
        out_file=None,
        show_stdout=True,
        show_cmd=True,
        extra_env=None,
        extra_paths=None,
        delete_env=None,
        **kwargs
    ):
    '''
    Run a command. Write the command to stdout before running it.

    Wait until the command finishes execution.

    :param cmd: command to run
    :type cmd: List[str]

    :param cmd_file: if not None, write the command to be run to that file
    :type cmd_file: str

    :param out_file: if not None, write the stdout and stderr of the command the file
    :type out_file: str

    :param show_stdout: wether to show stdout and stderr on the terminal or not
    :type show_stdout: bool

    :param extra_env: extra environment variables to add when running the command
    :type extra_env: Dict[str,str]
    '''
    if out_file is not None:
        stdout = subprocess.PIPE
        stderr = subprocess.STDOUT
    else:
        if show_stdout:
            stdout = None
            stderr = None
        else:
            stdout = subprocess.DEVNULL
            stderr = subprocess.DEVNULL
    if extra_env is None:
        extra_env = {}
    if delete_env is None:
        delete_env = []
    if 'cwd' in kwargs:
        cwd = kwargs['cwd']
    else:
        cwd = os.getcwd()
    env = os.environ.copy()
    env.update(extra_env)
    if extra_paths is not None:
        path = ':'.join(extra_paths)
        if 'PATH' in os.environ:
            path += ':' + os.environ['PATH']
        env['PATH'] = path
    for key in delete_env:
        if key in env:
            del env[key]
    if show_cmd:
        print_cmd(cmd, cwd=cwd, cmd_file=cmd_file, extra_env=extra_env, extra_paths=extra_paths)

    # Otherwise Ctrl + C gives:
    # - ugly Python stack trace for gem5 (QEMU takes over terminal and is fine).
    # - kills Python, and that then kills GDB: https://stackoverflow.com/questions/19807134/does-python-always-raise-an-exception-if-you-do-ctrlc-when-a-subprocess-is-exec
    sigint_old = signal.getsignal(signal.SIGINT)
    signal.signal(signal.SIGINT, signal.SIG_IGN)

    # Otherwise BrokenPipeError when piping through | grep
    # But if I do this, my terminal gets broken at the end. Why, why, why.
    # https://stackoverflow.com/questions/14207708/ioerror-errno-32-broken-pipe-python
    # Ignoring the exception is not enough as it prints a warning anyways.
    #sigpipe_old = signal.getsignal(signal.SIGPIPE)
    #signal.signal(signal.SIGPIPE, signal.SIG_DFL)

    # https://stackoverflow.com/questions/15535240/python-popen-write-to-stdout-and-log-file-simultaneously/52090802#52090802
    with subprocess.Popen(cmd, stdout=stdout, stderr=stderr, env=env, **kwargs) as proc:
        if out_file is not None:
            os.makedirs(os.path.split(os.path.abspath(out_file))[0], exist_ok=True)
            with open(out_file, 'bw') as logfile:
                while True:
                    byte = proc.stdout.read(1)
                    if byte:
                        if show_stdout:
                            sys.stdout.buffer.write(byte)
                            try:
                                sys.stdout.flush()
                            except BlockingIOError:
                                # TODO understand. Why, Python, why.
                                pass
                        logfile.write(byte)
                    else:
                        break
    signal.signal(signal.SIGINT, sigint_old)
    #signal.signal(signal.SIGPIPE, sigpipe_old)
    return proc.returncode

def setup(parser):
    '''
    Parse the command line arguments, and setup several variables based on them.
    Typically done after getting inputs from the command line arguments.
    '''
    global this
    args = parser.parse_args()
    if args.arch in this.arch_map:
        args.arch = this.arch_map[args.arch]
    this.machine = args.machine
    if args.arch == 'arm':
        this.armv = 7
        this.gem5_arch = 'ARM'
        this.mcpu = 'cortex-a15'
        this.crosstool_ng_prefix = 'arm-unknown-eabi'
        if args.gem5:
            if this.machine is None:
                this.machine = 'VExpress_GEM5_V1'
        else:
            if this.machine is None:
                this.machine = 'virt'
    elif args.arch == 'aarch64':
        this.armv = 8
        this.gem5_arch = 'ARM'
        this.mcpu = 'cortex-a57'
        this.crosstool_ng_prefix = 'aarch64-unknown-elf'
        if args.gem5:
            if this.machine is None:
                this.machine = 'VExpress_GEM5_V1'
        else:
            if this.machine is None:
                this.machine = 'virt'
    elif args.arch == 'x86_64':
        this.crosstool_ng_prefix = 'TODO'
        this.gem5_arch = 'X86'
        if args.gem5:
            if this.machine is None:
                this.machine = 'TODO'
        else:
            if this.machine is None:
                this.machine = 'pc'
    this.buildroot_out_dir = os.path.join(this.out_dir, 'buildroot')
    this.buildroot_build_dir = os.path.join(this.buildroot_out_dir, 'build', args.buildroot_build_id, args.arch)
    this.buildroot_download_dir = os.path.join(this.buildroot_out_dir, 'download')
    this.buildroot_config_file = os.path.join(this.buildroot_build_dir, '.config')
    this.build_dir = os.path.join(this.buildroot_build_dir, 'build')
    this.linux_build_dir = os.path.join(this.build_dir, 'linux-custom')
    this.linux_variant_dir = '{}.{}'.format(this.linux_build_dir, args.linux_build_id)
    this.vmlinux = os.path.join(this.linux_variant_dir, "vmlinux")
    this.qemu_build_dir = os.path.join(this.out_dir, 'qemu', args.qemu_build_id)
    this.qemu_executable_basename = 'qemu-system-{}'.format(args.arch)
    this.qemu_executable = os.path.join(this.qemu_build_dir, '{}-softmmu'.format(args.arch), this.qemu_executable_basename)
    this.qemu_img_basename = 'qemu-img'
    this.qemu_img_executable = os.path.join(this.qemu_build_dir, this.qemu_img_basename)
    this.qemu_guest_build_dir = os.path.join(this.build_dir, 'qemu-custom')
    this.host_dir = os.path.join(this.buildroot_build_dir, 'host')
    this.host_bin_dir = os.path.join(this.host_dir, 'usr', 'bin')
    this.buildroot_images_dir = os.path.join(this.buildroot_build_dir, 'images')
    this.rootfs_raw_file = os.path.join(this.buildroot_images_dir, 'rootfs.ext2')
    this.qcow2_file = this.rootfs_raw_file + '.qcow2'
    this.staging_dir = os.path.join(this.buildroot_build_dir, 'staging')
    this.target_dir = os.path.join(this.buildroot_build_dir, 'target')
    this.run_dir_base = os.path.join(this.out_dir, 'run')
    this.gem5_run_dir = os.path.join(this.run_dir_base, 'gem5', args.arch, str(args.run_id))
    this.m5out_dir = os.path.join(this.gem5_run_dir, 'm5out')
    this.stats_file = os.path.join(this.m5out_dir, 'stats.txt')
    this.trace_txt_file = os.path.join(this.m5out_dir, 'trace.txt')
    this.gem5_readfile = os.path.join(this.gem5_run_dir, 'readfile')
    this.gem5_termout_file = os.path.join(this.gem5_run_dir, 'termout.txt')
    this.qemu_run_dir = os.path.join(this.run_dir_base, 'qemu', args.arch, str(args.run_id))
    this.qemu_trace_basename = 'trace.bin'
    this.qemu_trace_file = os.path.join(this.qemu_run_dir, 'trace.bin')
    this.qemu_trace_txt_file = os.path.join(this.qemu_run_dir, 'trace.txt')
    this.qemu_termout_file = os.path.join(this.qemu_run_dir, 'termout.txt')
    this.qemu_rrfile = os.path.join(this.qemu_run_dir, 'rrfile')
    this.gem5_out_dir = os.path.join(this.out_dir, 'gem5')
    this.gem5_build_dir = os.path.join(this.gem5_out_dir, args.gem5_build_id, args.gem5_build_type)
    this.gem5_fake_iso = os.path.join(this.gem5_out_dir, 'fake.iso')
    this.gem5_m5term = os.path.join(this.gem5_build_dir, 'm5term')
    this.gem5_build_build_dir = os.path.join(this.gem5_build_dir, 'build')
    this.gem5_executable = os.path.join(this.gem5_build_build_dir, gem5_arch, 'gem5.{}'.format(args.gem5_build_type))
    this.gem5_system_dir = os.path.join(this.gem5_build_dir, 'system')
    this.crosstool_ng_out_dir = os.path.join(this.out_dir, 'crosstool-ng')
    this.crosstool_ng_buildid_dir = os.path.join(this.crosstool_ng_out_dir, 'build', args.crosstool_ng_build_id)
    this.crosstool_ng_install_dir = os.path.join(this.crosstool_ng_buildid_dir, 'install', args.arch)
    this.crosstool_ng_bin_dir = os.path.join(this.crosstool_ng_install_dir, 'bin')
    this.crosstool_ng_util_dir = os.path.join(this.crosstool_ng_buildid_dir, 'util')
    this.crosstool_ng_config = os.path.join(this.crosstool_ng_util_dir, '.config')
    this.crosstool_ng_defconfig = os.path.join(this.crosstool_ng_util_dir, 'defconfig')
    this.crosstool_ng_executable = os.path.join(this.crosstool_ng_util_dir, 'ct-ng')
    this.crosstool_ng_build_dir = os.path.join(this.crosstool_ng_buildid_dir, 'build')
    this.crosstool_ng_download_dir = os.path.join(this.crosstool_ng_out_dir, 'download')
    this.gem5_default_src_dir = os.path.join(submodules_dir, 'gem5')
    if args.gem5_source is not None:
        this.gem5_src_dir = args.gem5_source
        assert(os.path.exists(args.gem5_source))
    else:
        if args.gem5_worktree is not None:
            this.gem5_src_dir = os.path.join(this.gem5_non_default_src_root_dir, args.gem5_worktree)
        else:
            this.gem5_src_dir = this.gem5_default_src_dir
    if args.gem5:
        this.executable = this.gem5_executable
        this.run_dir = this.gem5_run_dir
        this.termout_file = this.gem5_termout_file
    else:
        this.executable = this.qemu_executable
        this.run_dir = this.qemu_run_dir
        this.termout_file = this.qemu_termout_file
    this.gem5_config_dir = os.path.join(this.gem5_src_dir, 'configs')
    this.gem5_se_file = os.path.join(this.gem5_config_dir, 'example', 'se.py')
    this.gem5_fs_file = os.path.join(this.gem5_config_dir, 'example', 'fs.py')
    this.run_cmd_file = os.path.join(this.run_dir, 'run.sh')
    if args.arch == 'arm':
        this.linux_image = os.path.join('arch', 'arm', 'boot', 'zImage')
    elif args.arch == 'aarch64':
        this.linux_image = os.path.join('arch', 'arm64', 'boot', 'Image')
    elif args.arch == 'x86_64':
        this.linux_image = os.path.join('arch', 'x86', 'boot', 'bzImage')
    this.linux_image = os.path.join(this.linux_variant_dir, linux_image)

    # Ports.
    if args.port_offset is None:
        try:
            args.port_offset = int(args.run_id)
        except ValueError:
            args.port_offset = 0
    if args.gem5:
        this.gem5_telnet_port = 3456 + args.port_offset
        this.gdb_port = 7000 + args.port_offset
    else:
        this.qemu_base_port = 45454 + 10 * args.port_offset
        this.qemu_monitor_port = this.qemu_base_port + 0
        this.qemu_hostfwd_generic_port = this.qemu_base_port + 1
        this.qemu_hostfwd_ssh_port = this.qemu_base_port + 2
        this.qemu_gdb_port = this.qemu_base_port + 3
        this.gdb_port = this.qemu_gdb_port

    # Baremetal.
    this.baremetal = args.baremetal
    this.baremetal_lib_basename = 'lib'
    this.baremetal_src_dir = os.path.join(this.root_dir, 'baremetal')
    this.baremetal_src_lib_dir = os.path.join(this.baremetal_src_dir, this.baremetal_lib_basename)
    this.c_ext = '.c'
    this.asm_ext = '.S'
    this.obj_ext = '.o'
    if args.gem5:
        this.simulator_name = 'gem5'
    else:
        this.simulator_name = 'qemu'
    this.baremetal_out_dir = os.path.join(out_dir, 'baremetal', args.arch, this.simulator_name, this.machine)
    this.baremetal_out_lib_dir = os.path.join(this.baremetal_out_dir, this.baremetal_lib_basename)
    this.baremetal_out_ext = '.elf'

    # Image.
    if args.baremetal is None:
        if args.gem5:
            this.image = this.vmlinux
            this.disk_image = this.rootfs_raw_file
        else:
            this.image = this.linux_image
            this.disk_image = this.qcow2_file
    else:
        this.disk_image = this.gem5_fake_iso
        paths = [
            os.path.join(this.baremetal_out_dir, this.baremetal),
            os.path.join(
                this.baremetal_out_dir,
                os.path.relpath(this.baremetal, this.baremetal_src_dir),
            )
        ]
        paths[:] = [os.path.splitext(path)[0] + this.baremetal_out_ext for path in paths]
        found = False
        for path in paths:
            if os.path.exists(path):
                found = True
                break
        if not found and this.baremetal != 'all':
            raise Exception('Baremetal ELF file not found. Tried:\n' + '\n'.join(paths))
        this.image = path
    return args

def write_configs(config_path, configs, config_fragments=None):
    """
    Write extra configs into the Buildroot config file.
    TODO Can't get rid of these for now with nice fragments:
    http://stackoverflow.com/questions/44078245/is-it-possible-to-use-config-fragments-with-buildroots-config
    """
    if config_fragments is None:
        config_fragments = []
    with open(config_path, 'a') as config_file:
        for config_fragment in config_fragments:
            with open(config_fragment, 'r') as config_fragment:
                for line in config_fragment:
                    config_file.write(line)
        for config in configs:
            config_file.write(config + '\n')