test: Record and silence console in tests

When running sandbox tests, silence the console to avoid unwanted output.
Also, record the console in case tests want to check it.

The -v option can be used to enable stdout during tests.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c
index 4c38fab..0dda4fc 100644
--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@@ -257,6 +257,14 @@
 SANDBOX_CMDLINE_OPT_SHORT(terminal, 't', 1,
 			  "Set terminal to raw/cooked mode");
 
+static int sandbox_cmdline_cb_verbose(struct sandbox_state *state,
+				      const char *arg)
+{
+	state->show_test_output = true;
+	return 0;
+}
+SANDBOX_CMDLINE_OPT_SHORT(verbose, 'v', 0, "Show test output");
+
 int main(int argc, char *argv[])
 {
 	struct sandbox_state *state;