event: Introduce EVT_POST_PREBOOT event

Add a new EVT_POST_PREBOOT event type which is fired in main_loop()
after the preboot command has been executed.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

common/event.c

@@ -49,6 +49,9 @@ const char *const type_name[] = {
 	/* main loop events */
 	"main_loop",
 
+	/* post preboot events */
+	"post_preboot",
+
 	/* livetree has been built */
 	"of_live_init",
 };

common/main.c

@@ -19,6 +19,7 @@
 #include <net.h>
 #include <version_string.h>
 #include <efi_loader.h>
+#include <event.h>
 
 static void run_preboot_environment_command(void)
 {
@@ -53,6 +54,9 @@ void main_loop(void)
 	if (IS_ENABLED(CONFIG_USE_PREBOOT))
 		run_preboot_environment_command();
 
+	if (event_notify_null(EVT_POST_PREBOOT))
+		return;
+
 	if (IS_ENABLED(CONFIG_UPDATE_TFTP))
 		update_tftp(0UL, NULL, NULL);
 

include/event.h

@@ -153,6 +153,15 @@ enum event_t {
 	 */
 	EVT_MAIN_LOOP,
 
+	/**
+	 * @EVT_POST_PREBOOT:
+	 * This event is triggered in main_loop() after the preboot command
+	 * has run, so that devices initialised by preboot (e.g. USB, UFS)
+	 * are available to event handlers. Its parameter is NULL.
+	 * A non-zero return value causes the boot to fail.
+	 */
+	EVT_POST_PREBOOT,
+
 	/**
 	 * @EVT_OF_LIVE_BUILT:
 	 * This event is triggered immediately after the live device tree has been