Don't initialise the queuebuf unconditionally

Currently, it is only used by 6LoWPAN when fragmentation is enabled, by TSCH and by CSMA. Platforms that disable fragmentation and choose a different MAC layer (e.g. NULLMAC) will unnecessarily end up with the module linked in the image, wasting flash and/or RAM space.

arch/platform/cooja/contiki-cooja-main.c

@@ -206,8 +206,6 @@ contiki_init()
            longaddr[4], longaddr[5], longaddr[6], longaddr[7]);
   }
 
-  queuebuf_init();
-
   /* Initialize communication stack */
   netstack_init();
   printf("%s/%s\n",

os/contiki-main.c

@@ -43,7 +43,6 @@
 #include "contiki.h"
 #include "contiki-net.h"
 #include "sys/platform.h"
-#include "net/queuebuf.h"
 #include "dev/watchdog.h"
 
 #if BUILD_WITH_ORCHESTRA
@@ -92,7 +91,6 @@ main(void)
 
 #if NETSTACK_CONF_WITH_IPV6
   memcpy(&uip_lladdr.addr, &linkaddr_node_addr, sizeof(uip_lladdr.addr));
-  queuebuf_init();
   process_start(&tcpip_process, NULL);
 #endif /* NETSTACK_CONF_WITH_IPV6 */
 

os/net/ipv6/sicslowpan.c

@@ -1983,6 +1983,11 @@ sicslowpan_init(void)
 #endif /* SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 1 */
 
 #endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPHC */
+
+  /* We use the queuebuf module if fragmentation is enabled */
+#if SICSLOWPAN_CONF_FRAG
+  queuebuf_init();
+#endif
 }
 /*--------------------------------------------------------------------*/
 int

os/net/mac/csma/csma-output.c

@@ -549,4 +549,5 @@ csma_output_init(void)
   memb_init(&packet_memb);
   memb_init(&metadata_memb);
   memb_init(&neighbor_memb);
+  queuebuf_init();
 }

os/net/mac/tsch/tsch.c

@@ -921,7 +921,8 @@ tsch_init(void)
     LOG_ERR("! TSCH_HOPPING_SEQUENCE_MAX_LEN < sizeof(TSCH_DEFAULT_HOPPING_SEQUENCE). Abort init.\n");
   }
 
-  /* Init TSCH sub-modules */
+  /* Init the queuebuf and TSCH sub-modules */
+  queuebuf_init();
   tsch_reset();
   tsch_queue_init();
   tsch_schedule_init();