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.
Same for the EFI_STUB thing which I just noticed, actually
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?
> return ret;
> }
>
> void of_live_free(struct device_node *root)
>
> --
> 2.49.0
>
Regards,
Simon
