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author | Simon Glass <sjg@chromium.org> | 2023-01-20 14:46:05 -0700 |
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committer | Heinrich Schuchardt <heinrich.schuchardt@canonical.com> | 2023-01-27 18:31:59 +0100 |
commit | d67811aa9a7d85793e73bead898f30139265c3c2 (patch) | |
tree | cfb4cbcf72e24d9ffdfed10bc69f898794968e12 /doc/develop/event.rst | |
parent | 1402f1dcee07bd87953f247cd61d1ebc00ae2d1f (diff) | |
download | u-boot-d67811aa9a7d85793e73bead898f30139265c3c2.tar.gz |
event: Document dynamic event handlers
Add mention of this feature in the event documentation.
Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'doc/develop/event.rst')
-rw-r--r-- | doc/develop/event.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/doc/develop/event.rst b/doc/develop/event.rst index 6951ec97e7..4ff5934837 100644 --- a/doc/develop/event.rst +++ b/doc/develop/event.rst @@ -64,3 +64,26 @@ in an image, use $(CROSS_COMPILE)nm:: nm u-boot |grep evspy |grep list 00000000002d6300 D _u_boot_list_2_evspy_info_2_EVT_MISC_INIT_F + +Logging is also available. Events use category `LOGC_EVENT`, so you can enable +logging on that, or add `#define LOG_DEBUG` to the top of `common/event.c` to +see events being sent. + + +Dynamic events +-------------- + +Static events provide a way of dealing with events known at build time. In some +cases we want to attach an event handler at runtime. For example, we may wish +to be notified when a particular device is probed or removed. + +This can be handled by enabling `CONFIG_EVENT_DYNAMIC`. It is then possible to +call `event_register()` to register a new handler for a particular event. + +Dynamic event handlers are called after all the static event spy handlers have +been processed. Of course, since dynamic event handlers are created at runtime +it is not possible to use the `event_dump.py` to see them. + +At present there is no way to list dynamic event handlers from the command line, +nor to deregister a dynamic event handler. These features can be added when +needed. |