Merge branch '2022-03-09-events-subsystem' into next

To quote the author:
It is a common need in U-Boot to have one subsystem notify another
when something happens. An example is reading a partition table when a
new block device is set up.

It is also common to add weak functions and 'hook' functions to modify
how U-Boot works. See for example ft_board_setup() and the like.

U-Boot would benefit from a generic mechanism to handle these cases,
with the ability to hook into various 'events' in a
subsystem-independent and transparent way.

This series provides a way to create and dispatch events, with a way of
registering a 'spy' which watches for events of different types. This
allows 'hook' functions to be created in a generic way.

It also includes a script to list the hooks in an image, which is a bit
easier to debug than weak functions, as well as an 'event' command to
do the same from within U-Boot.

These 'static' events can be used to replace hooks like misc_init_f(),
for example. Also included is basic support for 'dynamic' events, where
a spy can be registered at runtime. The need for this is still being
figured out.

1 files changed, 20 insertions, 0 deletions

diff --git a/test/py/tests/test_event_dump.py b/test/py/tests/test_event_dump.py
new file mode 100644
index 00000000000..b753e804ac3
--- /dev/null
+++ b/test/py/tests/test_event_dump.py
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright 2021 Google LLC
+# Written by Simon Glass <sjg@chromium.org>
+
+import pytest
+import re
+import u_boot_utils as util
+
+# This is only a partial test - coverting 64-bit sandbox. It does not test
+# big-endian images, nor 32-bit images
+@pytest.mark.boardspec('sandbox')
+def test_event_dump(u_boot_console):
+    """Test that the "help" command can be executed."""
+    cons = u_boot_console
+    sandbox = cons.config.build_dir + '/u-boot'
+    out = util.run_and_log(cons, ['scripts/event_dump.py', sandbox])
+    expect = '''.*Event type            Id                              Source location
+--------------------  ------------------------------  ------------------------------
+EVT_MISC_INIT_F       sandbox_misc_init_f             .*arch/sandbox/cpu/start.c:'''
+    assert re.match(expect, out, re.MULTILINE) is not None