program loading: add optional is_loader_active() callback

Add a way for a loader to indicate if it is active. Such users
of this callback would be vboot which can indicate to the rest
of the system that it isn't active. is_loader_active() also
gives vboot a chance to perform the necessary work to make
said decision.

Change-Id: I6679ac75b19bb1bfff9c2b709da5591986f752ff
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/10022
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/src/lib/loaders/load_and_run_romstage.c b/src/lib/loaders/load_and_run_romstage.c
index 1c2ed77abf..b54bfc7e5c 100644
--- a/src/lib/loaders/load_and_run_romstage.c
+++ b/src/lib/loaders/load_and_run_romstage.c
@@ -41,11 +41,26 @@ void run_romstage(void)
 	};
 
 	for (i = 0; i < ARRAY_SIZE(loaders); i++) {
+		/* Default loader state is active. */
+		int ret = 1;
 		const struct prog_loader_ops *ops;
 
 		ops = loaders[i];
 
-		printk(BIOS_DEBUG, "Trying %s romstage loader.\n", ops->name);
+		if (ops->is_loader_active != NULL)
+			ret = ops->is_loader_active(&romstage);
+
+		if (ret == 0) {
+			printk(BIOS_DEBUG, "%s romstage loader inactive.\n",
+				ops->name);
+			continue;
+		} else if (ret < 0) {
+			printk(BIOS_DEBUG, "%s romstage loader failure.\n",
+				ops->name);
+			continue;
+		}
+
+		printk(BIOS_DEBUG, "%s romstage loader active.\n", ops->name);
 
 		timestamp_add_now(TS_START_COPYROM);