Hi Simon,
On 4/10/25 13:27, Simon Glass wrote:
Hi Caleb,
On Wed, 9 Apr 2025 at 11:17, Caleb Connolly <caleb.conno...@linaro.org> wrote:
OF_LIVE offers a variety of benefits, one of them being that the live
tree can be modified without caring about the underlying FDT. This is
particularly valuable for working around U-Boot limitations like lacking
USB superspeed support on Qualcomm platforms, no runtime OTG, or
peripherals like the sdcard being broken (and displaying potentially
worrying error messages).
Add an event to signal when the live tree has been built so that we can
apply fixups to it directly before devices are bound.
Signed-off-by: Caleb Connolly <caleb.conno...@linaro.org>
---
common/event.c | 3 +++
include/event.h | 9 +++++++++
lib/of_live.c | 3 +++
3 files changed, 15 insertions(+)
diff --git a/common/event.c b/common/event.c
index
dda569d447851f559a83f98fb7b1f3543156eab5..8d7513eb10b61919e1e784481dfdcc076be14986
100644
--- a/common/event.c
+++ b/common/event.c
@@ -47,8 +47,11 @@ const char *const type_name[] = {
"ft_fixup",
/* main loop events */
"main_loop",
+
+ /* livetree has been built */
+ "of_live_init",
};
_Static_assert(ARRAY_SIZE(type_name) == EVT_COUNT, "event type_name size");
#endif
diff --git a/include/event.h b/include/event.h
index
75141a192a48b0931667632f41be8ff4d6139f7c..3fc673ba635ed45467aae8587705d37bef1c2a3f
100644
--- a/include/event.h
+++ b/include/event.h
@@ -152,8 +152,17 @@ enum event_t {
* A non-zero return value causes the boot to fail.
*/
EVT_MAIN_LOOP,
+ /**
+ * @EVT_OF_LIVE_INIT:
+ * This event is triggered immediately after the live device tree has
been
+ * built. This allows for machine specific fixups to be done to the
live tree
+ * (like disabling known-unsupported devices) before DM init happens.
This
+ * event is only available if OF_LIVE is enabled and is only used after
relocation.
+ */
+ EVT_OF_LIVE_INIT,
+
/**
* @EVT_COUNT:
* This constants holds the maximum event number + 1 and is used when
* looping over all event classes.
diff --git a/lib/of_live.c b/lib/of_live.c
index
90b9459ede313e492e28c8556c730f3bd8aaa9df..e1962b8f1fb9d8c2c87d04ca4e238a1e4d00376a
100644
--- a/lib/of_live.c
+++ b/lib/of_live.c
@@ -10,8 +10,9 @@
#define LOG_CATEGORY LOGC_DT
#include <abuf.h>
+#include <event.h>
#include <log.h>
#include <linux/libfdt.h>
#include <of_live.h>
#include <malloc.h>
@@ -334,8 +335,10 @@ int of_live_build(const void *fdt_blob, struct device_node
**rootp)
return ret;
}
debug("%s: stop\n", __func__);
+ event_notify_null(EVT_OF_LIVE_INIT);
+
This should go in initr_of_live() since the function you are dealing
with here is supposed to just do the live build.
Well, we only every call this function from one place right now, but if
it was called multiple times for some reason then I would want to be
able to re-apply fixups to the new live tree.... I guess it should
probably pass in *rootp to the event handler, let me rework that.>
Same for the EFI_STUB thing which I just noticed, actually
what EFI_STUB thing?>
Also please check for error
Otherwise this seems OK to me. I do wonder why we can't use
EVT_FT_FIXUP though. Could you add mention of that to your comment in
event.h?
Because FT_FIXUP is for fixing up the flat tree before starting the OS?
these are obviously different things imo, im not sure how i could
clarify this.>
return ret;
}
void of_live_free(struct device_node *root)
--
2.49.0
Regards,
Simon
--
Caleb (they/them)
