AP_BoardConfig: wait for UAVCAN initialization complete signal

libraries/AP_BoardConfig/AP_BoardConfig.cpp

@@ -99,6 +99,12 @@ const AP_Param::GroupInfo AP_BoardConfig::var_info[] = {
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_PX4 && !defined(CONFIG_ARCH_BOARD_PX4FMU_V1)
 extern "C" int uavcan_main(int argc, const char *argv[]);
+
+#define _UAVCAN_IOCBASE             (0x4000)                        // IOCTL base for module UAVCAN
+#define _UAVCAN_IOC(_n)             (_IOC(_UAVCAN_IOCBASE, _n))
+
+#define UAVCAN_IOCG_NODEID_INPROGRESS  _UAVCAN_IOC(1)               // query if node identification is in progress
+
 #endif
 
 void AP_BoardConfig::init()
@@ -159,10 +165,18 @@ void AP_BoardConfig::init()
         if (ret != 0) {
             hal.console->printf("UAVCAN: failed to start servers\n");
         } else {
-            hal.console->printf("UAVCAN: servers started\n");
-            // give some time for CAN bus initialisation
+            fd = open("/dev/uavcan/esc", 0); // design flaw of uavcan driver, this should be /dev/uavcan/node one day
+            if (fd == -1) {
+                AP_HAL::panic("Configuration invalid - unable to open /dev/uavcan/esc");
+            }
+
+            // delay startup, UAVCAN still discovering nodes
+            while (ioctl(fd, UAVCAN_IOCG_NODEID_INPROGRESS,0) == OK) {
                 hal.scheduler->delay(500);
             }
+            hal.console->printf("UAVCAN: node discovery complete\n");
+            close(fd);
+        }
    }
 #endif