l1ctl protocol: Introduce multi-part message DONE flag

In case a single request from L2 triggers multiple response messages
from L1, we need a way to signal via L1CTL if the response is the
final or some intermediate response.

1 files changed, 4 insertions, 1 deletions

diff --git a/include/l1a_l23_interface.h b/include/l1a_l23_interface.h
index e9def59c..690a6baa 100644
--- a/include/l1a_l23_interface.h
+++ b/include/l1a_l23_interface.h
@@ -41,9 +41,12 @@
  * that it will avoid some unaligned access.
  */
 
+/* there are no more messages in a sequence */
+#define L1CTL_F_DONE	0x01
+
 struct l1ctl_hdr {
 	uint8_t msg_type;
-	uint8_t padding;
+	uint8_t flags;
 	uint8_t data[0];
 } __attribute__((packed));