uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/lib/test-driver/test_driver/__init__.py

@@ -0,0 +1,128 @@
+from pathlib import Path
+import argparse
+import ptpython.repl
+import os
+import time
+
+from test_driver.logger import rootlog
+from test_driver.driver import Driver
+
+
+class EnvDefault(argparse.Action):
+    """An argpars Action that takes values from the specified
+    environment variable as the flags default value.
+    """
+
+    def __init__(self, envvar, required=False, default=None, nargs=None, **kwargs):  # type: ignore
+        if not default and envvar:
+            if envvar in os.environ:
+                if nargs is not None and (nargs.isdigit() or nargs in ["*", "+"]):
+                    default = os.environ[envvar].split()
+                else:
+                    default = os.environ[envvar]
+                kwargs["help"] = (
+                    kwargs["help"] + f" (default from environment: {default})"
+                )
+        if required and default:
+            required = False
+        super(EnvDefault, self).__init__(
+            default=default, required=required, nargs=nargs, **kwargs
+        )
+
+    def __call__(self, parser, namespace, values, option_string=None):  # type: ignore
+        setattr(namespace, self.dest, values)
+
+
+def writeable_dir(arg: str) -> Path:
+    """Raises an ArgumentTypeError if the given argument isn't a writeable directory
+    Note: We want to fail as early as possible if a directory isn't writeable,
+    since an executed nixos-test could fail (very late) because of the test-driver
+    writing in a directory without proper permissions.
+    """
+    path = Path(arg)
+    if not path.is_dir():
+        raise argparse.ArgumentTypeError("{0} is not a directory".format(path))
+    if not os.access(path, os.W_OK):
+        raise argparse.ArgumentTypeError(
+            "{0} is not a writeable directory".format(path)
+        )
+    return path
+
+
+def main() -> None:
+    arg_parser = argparse.ArgumentParser(prog="nixos-test-driver")
+    arg_parser.add_argument(
+        "-K",
+        "--keep-vm-state",
+        help="re-use a VM state coming from a previous run",
+        action="store_true",
+    )
+    arg_parser.add_argument(
+        "-I",
+        "--interactive",
+        help="drop into a python repl and run the tests interactively",
+        action=argparse.BooleanOptionalAction,
+    )
+    arg_parser.add_argument(
+        "--start-scripts",
+        metavar="START-SCRIPT",
+        action=EnvDefault,
+        envvar="startScripts",
+        nargs="*",
+        help="start scripts for participating virtual machines",
+    )
+    arg_parser.add_argument(
+        "--vlans",
+        metavar="VLAN",
+        action=EnvDefault,
+        envvar="vlans",
+        nargs="*",
+        help="vlans to span by the driver",
+    )
+    arg_parser.add_argument(
+        "-o",
+        "--output_directory",
+        help="""The path to the directory where outputs copied from the VM will be placed.
+                By e.g. Machine.copy_from_vm or Machine.screenshot""",
+        default=Path.cwd(),
+        type=writeable_dir,
+    )
+    arg_parser.add_argument(
+        "testscript",
+        action=EnvDefault,
+        envvar="testScript",
+        help="the test script to run",
+        type=Path,
+    )
+
+    args = arg_parser.parse_args()
+
+    if not args.keep_vm_state:
+        rootlog.info("Machine state will be reset. To keep it, pass --keep-vm-state")
+
+    with Driver(
+        args.start_scripts,
+        args.vlans,
+        args.testscript.read_text(),
+        args.output_directory.resolve(),
+        args.keep_vm_state,
+    ) as driver:
+        if args.interactive:
+            ptpython.repl.embed(driver.test_symbols(), {})
+        else:
+            tic = time.time()
+            driver.run_tests()
+            toc = time.time()
+            rootlog.info(f"test script finished in {(toc-tic):.2f}s")
+
+
+def generate_driver_symbols() -> None:
+    """
+    This generates a file with symbols of the test-driver code that can be used
+    in user's test scripts. That list is then used by pyflakes to lint those
+    scripts.
+    """
+    d = Driver([], [], "", Path())
+    test_symbols = d.test_symbols()
+    with open("driver-symbols", "w") as fp:
+        fp.write(",".join(test_symbols.keys()))