test: Allow connecting to a running board

Sometimes we know that the board is already running the right software,
so provide an option to allow running of tests directly, without first
resetting the board.

This saves time when re-running a test where only the Python code is
changing.

Note that this feature is open to errors, since the user must know that
the board is in a fit state to execute tests. It is useful for repeated
iteration on a particular test, where it can save quite a bit of time.

Signed-off-by: Simon Glass <sjg@chromium.org>

test/py/conftest.py

@@ -80,6 +80,8 @@ def pytest_addoption(parser):
     parser.addoption('--gdbserver', default=None,
         help='Run sandbox under gdbserver. The argument is the channel '+
         'over which gdbserver should communicate, e.g. localhost:1234')
+    parser.addoption('--use-running-system', default=False, action='store_true',
+        help="Assume that U-Boot is ready and don't wait for a prompt")
 
 def run_build(config, source_dir, build_dir, board_type, log):
     """run_build: Build U-Boot
@@ -254,6 +256,7 @@ def pytest_configure(config):
     ubconfig.board_type = board_type
     ubconfig.board_identity = board_identity
     ubconfig.gdbserver = gdbserver
+    ubconfig.use_running_system = config.getoption('use_running_system')
     ubconfig.dtb = build_dir + '/arch/sandbox/dts/test.dtb'
     ubconfig.connection_ok = True