diff --git a/Makefile.include b/Makefile.include
index 319ae29d7..3578730eb 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -46,11 +46,6 @@ UPPERCASE = _ABCDEFGHIJKLMNOPQRSTUVWXYZ_
 TARGET_UPPERCASE := ${strip ${shell echo $(TARGET) | sed y!$(LOWERCASE)!$(UPPERCASE)!}}
 CFLAGS += -DCONTIKI=1 -DCONTIKI_TARGET_$(TARGET_UPPERCASE)=1
 CFLAGS += -DCONTIKI_TARGET_STRING=\"$(TARGET)\"
-ifneq ($(BOARD),)
-TARGET_BOARD_UPPERCASE := ${strip ${shell echo $(BOARD) | sed y!$(LOWERCASE)!$(UPPERCASE)!}}
-CFLAGS += -DCONTIKI_BOARD_$(TARGET_BOARD_UPPERCASE)=1
-CFLAGS += -DCONTIKI_BOARD_STRING=\"$(BOARD)\"
-endif
 
 CFLAGS += -Wno-unused-const-variable
 
@@ -129,6 +124,12 @@ endif # $(BOARD) not empty
 
 PLATFORM_ACTION ?= build
 
+ifneq ($(BOARD),)
+  TARGET_BOARD_UPPERCASE := ${strip ${shell echo $(BOARD) | sed y!$(LOWERCASE)!$(UPPERCASE)!}}
+  CFLAGS += -DCONTIKI_BOARD_$(TARGET_BOARD_UPPERCASE)=1
+  CFLAGS += -DCONTIKI_BOARD_STRING=\"$(BOARD)\"
+endif
+
 # Configure MAC layer
 
 # The different options
diff --git a/arch/cpu/arm/cortex-m/Makefile.cortex-m b/arch/cpu/arm/cortex-m/Makefile.cortex-m
index 444df05cd..aebcf2bdd 100644
--- a/arch/cpu/arm/cortex-m/Makefile.cortex-m
+++ b/arch/cpu/arm/cortex-m/Makefile.cortex-m
@@ -1,3 +1,14 @@
 CONTIKI_ARM_DIRS += cortex-m cortex-m/CMSIS
 
+### Build syscalls for newlib
+MODULES += os/lib/newlib
+
+CUSTOM_RULE_LINK = 1
+
+.SECONDEXPANSION:
+
+%.elf: $(CPU_STARTFILES) $$(CONTIKI_OBJECTFILES) %.o $(PROJECT_OBJECTFILES) $(PROJECT_LIBRARIES) $(LDSCRIPT) $(TARGET_LIBS)
+	$(TRACE_LD)
+	$(Q)$(LD) $(LDFLAGS) ${filter-out $(LDSCRIPT) %.a,$^} ${filter %.a,$^} $(TARGET_LIBFLAGS) -o $@
+
 include $(CONTIKI)/arch/cpu/arm/Makefile.arm
diff --git a/arch/cpu/arm/cortex-m/cm3/Makefile.cm3 b/arch/cpu/arm/cortex-m/cm3/Makefile.cm3
index 6bd76135c..3cf216bfb 100644
--- a/arch/cpu/arm/cortex-m/cm3/Makefile.cm3
+++ b/arch/cpu/arm/cortex-m/cm3/Makefile.cm3
@@ -9,22 +9,10 @@ LDFLAGS += -Wl,-Map=$(CONTIKI_NG_PROJECT_MAP),--cref,--no-warn-mismatch
 
 OBJCOPY_FLAGS += --gap-fill 0xff
 
-### Build syscalls for newlib
-MODULES += os/lib/newlib
-
 CPU_STARTFILES = ${addprefix $(OBJECTDIR)/,${call oname, $(CPU_START_SOURCEFILES)}}
 
-### Compilation rules
-CUSTOM_RULE_LINK = 1
-
 ### Resolve any potential circular dependencies between the linked libraries
 ### See: https://stackoverflow.com/questions/5651869/gcc-what-are-the-start-group-and-end-group-command-line-options/5651895
 TARGET_LIBFLAGS := -Wl,--start-group $(TARGET_LIBFILES) -lm -Wl,--end-group
 
-.SECONDEXPANSION:
-
-%.elf: $(CPU_STARTFILES) $$(CONTIKI_OBJECTFILES) %.o $(PROJECT_OBJECTFILES) $(PROJECT_LIBRARIES) $(LDSCRIPT)
-	$(TRACE_LD)
-	$(Q)$(LD) $(LDFLAGS) ${filter-out $(LDSCRIPT) %.a,$^} ${filter %.a,$^} $(TARGET_LIBFLAGS) -o $@
-
 include $(CONTIKI)/arch/cpu/arm/cortex-m/Makefile.cortex-m
diff --git a/arch/cpu/arm/cortex-m/cm4/Makefile.cm4 b/arch/cpu/arm/cortex-m/cm4/Makefile.cm4
index 110e0697b..b0b592e43 100644
--- a/arch/cpu/arm/cortex-m/cm4/Makefile.cm4
+++ b/arch/cpu/arm/cortex-m/cm4/Makefile.cm4
@@ -9,20 +9,10 @@ LDFLAGS += -Wl,-Map=$(CONTIKI_NG_PROJECT_MAP),--cref,--no-warn-mismatch
 
 OBJCOPY_FLAGS += --gap-fill 0xff
 
-### Build syscalls for newlib
-MODULES += os/lib/newlib
-
 CPU_STARTFILES = ${addprefix $(OBJECTDIR)/,${call oname, $(CPU_START_SOURCEFILES)}}
 
-### Compilation rules
-CUSTOM_RULE_LINK = 1
-
 ### Resolve any potential circular dependencies between the linked libraries
 ### See: https://stackoverflow.com/questions/5651869/gcc-what-are-the-start-group-and-end-group-command-line-options/5651895
 TARGET_LIBFLAGS := -Wl,--start-group $(TARGET_LIBFILES) -Wl,--end-group
 
-%.elf: $(CPU_STARTFILES) %.o $(PROJECT_OBJECTFILES) $(PROJECT_LIBRARIES) $(CONTIKI_NG_TARGET_LIB) $(TARGET_LIBS)
-	$(TRACE_LD)
-	$(Q)$(LD) $(LDFLAGS) ${filter %.o %.a,$^} $(TARGET_LIBFLAGS) -o $@
-
 include $(CONTIKI)/arch/cpu/arm/cortex-m/Makefile.cortex-m
diff --git a/arch/cpu/cc2538/cc2538-def.h b/arch/cpu/cc2538/cc2538-def.h
index 163456a14..defa4ecb0 100644
--- a/arch/cpu/cc2538/cc2538-def.h
+++ b/arch/cpu/cc2538/cc2538-def.h
@@ -36,11 +36,13 @@
 /*---------------------------------------------------------------------------*/
 #define RTIMER_ARCH_SECOND 32768
 /*---------------------------------------------------------------------------*/
+#define CC2538_PHY_OVERHEAD          3
+#define CC2538_BYTE_AIR_TIME         32
 /* 352us from calling transmit() until the SFD byte has been sent */
-#define CC2538_DELAY_BEFORE_TX     ((unsigned)US_TO_RTIMERTICKS(352))
+#define CC2538_DELAY_BEFORE_TX       ((unsigned)US_TO_RTIMERTICKS(352))
 /* 192us as in datasheet but ACKs are not always received, so adjusted to 250us */
-#define CC2538_DELAY_BEFORE_RX     ((unsigned)US_TO_RTIMERTICKS(250))
-#define CC2538_DELAY_BEFORE_DETECT 0
+#define CC2538_DELAY_BEFORE_RX       ((unsigned)US_TO_RTIMERTICKS(250))
+#define CC2538_DELAY_BEFORE_DETECT   0
 /* Frame filtering done in software */
 #define TSCH_CONF_HW_FRAME_FILTERING  0
 
diff --git a/arch/cpu/cc26xx-cc13xx/cc26xx.ld b/arch/cpu/cc26xx-cc13xx/cc26xx.ld
index 649da32cf..4ea422558 100644
--- a/arch/cpu/cc26xx-cc13xx/cc26xx.ld
+++ b/arch/cpu/cc26xx-cc13xx/cc26xx.ld
@@ -96,6 +96,8 @@ SECTIONS
     /* These symbols are used by the stack check library. */
     _stack = .;
     _stack_origin = ORIGIN(SRAM) + LENGTH(SRAM);
+    _heap = _stack;
+    _eheap = _stack_origin;
 
     .ccfg :
     {
diff --git a/arch/cpu/native/Makefile.native b/arch/cpu/native/Makefile.native
index d7832d358..30883622d 100644
--- a/arch/cpu/native/Makefile.native
+++ b/arch/cpu/native/Makefile.native
@@ -20,6 +20,30 @@ endif
 CFLAGSNO = -Wall -g -I/usr/local/include $(CFLAGSWERROR)
 CFLAGS  += $(CFLAGSNO)
 
+### Are we building with code size optimisations?
+SMALL ?= 0
+
+# The optimizations on native platform cannot be enabled in GCC (not Clang) versions less than 7.2
+GCC_IS_CLANG := $(shell gcc --version 2> /dev/null | grep clang)
+ifneq ($(GCC_IS_CLANG),)
+  NATIVE_CAN_OPTIIMIZE = 1
+else
+  GCC_VERSION := $(shell gcc -dumpfullversion -dumpversion | cut -b1-3)
+  ifeq ($(shell expr $(GCC_VERSION) \>= 7.2), 1)
+  	NATIVE_CAN_OPTIIMIZE = 1
+  else
+  	NATIVE_CAN_OPTIIMIZE = 0
+  endif
+endif
+
+ifeq ($(NATIVE_CAN_OPTIIMIZE),1)
+  ifeq ($(SMALL),1)
+    CFLAGS += -Os
+  else
+    CFLAGS += -O2
+  endif
+endif
+
 ifeq ($(HOST_OS),Darwin)
 AROPTS = -rc
 LDFLAGS_WERROR := -Wl,-fatal_warnings
diff --git a/arch/cpu/nrf52832/ld/nrf52-pca10036-sd.ld b/arch/cpu/nrf52832/ld/nrf52-pca10036-sd.ld
index f3bc5bc43..2afa9e6e2 100644
--- a/arch/cpu/nrf52832/ld/nrf52-pca10036-sd.ld
+++ b/arch/cpu/nrf52832/ld/nrf52-pca10036-sd.ld
@@ -14,3 +14,5 @@ INCLUDE "nrf5x_common.ld"
 /* These symbols are used by the stack check library. */
 _stack = end;
 _stack_origin = ORIGIN(RAM) + LENGTH(RAM);
+_heap = _stack;
+_eheap = _stack_origin;
diff --git a/arch/cpu/nrf52832/ld/nrf52-pca10040-sd.ld b/arch/cpu/nrf52832/ld/nrf52-pca10040-sd.ld
index 0bc7349e3..b2c747f0a 100644
--- a/arch/cpu/nrf52832/ld/nrf52-pca10040-sd.ld
+++ b/arch/cpu/nrf52832/ld/nrf52-pca10040-sd.ld
@@ -14,3 +14,5 @@ INCLUDE "nrf5x_common.ld"
 /* These symbols are used by the stack check library. */
 _stack = end;
 _stack_origin = ORIGIN(RAM) + LENGTH(RAM);
+_heap = _stack;
+_eheap = _stack_origin;
diff --git a/arch/cpu/nrf52832/ld/nrf52.ld b/arch/cpu/nrf52832/ld/nrf52.ld
index 87fc9152d..3fead1250 100644
--- a/arch/cpu/nrf52832/ld/nrf52.ld
+++ b/arch/cpu/nrf52832/ld/nrf52.ld
@@ -14,3 +14,5 @@ INCLUDE "nrf5x_common.ld"
 /* These symbols are used by the stack check library. */
 _stack = end;
 _stack_origin = ORIGIN(RAM) + LENGTH(RAM);
+_heap = _stack;
+_eheap = _stack_origin;
diff --git a/arch/platform/cc2538dk/dev/board.h b/arch/platform/cc2538dk/dev/board.h
index 80f036fd7..2540b7ce7 100644
--- a/arch/platform/cc2538dk/dev/board.h
+++ b/arch/platform/cc2538dk/dev/board.h
@@ -220,6 +220,18 @@
 #endif  /* #if SPI1_IN_USE */
 /** @} */
 /*---------------------------------------------------------------------------*/
+/**
+ * \name CC2538 TSCH configuration
+ *
+ * @{
+ */
+#define RADIO_PHY_OVERHEAD        CC2538_PHY_OVERHEAD
+#define RADIO_BYTE_AIR_TIME       CC2538_BYTE_AIR_TIME
+#define RADIO_DELAY_BEFORE_TX     CC2538_DELAY_BEFORE_TX
+#define RADIO_DELAY_BEFORE_RX     CC2538_DELAY_BEFORE_RX
+#define RADIO_DELAY_BEFORE_DETECT CC2538_DELAY_BEFORE_DETECT
+/** @} */
+/*---------------------------------------------------------------------------*/
 /**
  * \name Device string used on startup
  * @{
diff --git a/arch/platform/openmote-cc2538/board.h b/arch/platform/openmote-cc2538/board.h
index abb89b8e2..6e2a15e46 100644
--- a/arch/platform/openmote-cc2538/board.h
+++ b/arch/platform/openmote-cc2538/board.h
@@ -174,6 +174,18 @@
 #define I2C_SDA_PIN              4
 /** @} */
 /*---------------------------------------------------------------------------*/
+/**
+ * \name CC2538 TSCH configuration
+ *
+ * @{
+ */
+#define RADIO_PHY_OVERHEAD        CC2538_PHY_OVERHEAD
+#define RADIO_BYTE_AIR_TIME       CC2538_BYTE_AIR_TIME
+#define RADIO_DELAY_BEFORE_TX     CC2538_DELAY_BEFORE_TX
+#define RADIO_DELAY_BEFORE_RX     CC2538_DELAY_BEFORE_RX
+#define RADIO_DELAY_BEFORE_DETECT CC2538_DELAY_BEFORE_DETECT
+/** @} */
+/*---------------------------------------------------------------------------*/
 /**
  * \name Device string used on startup
  * @{
diff --git a/os/dev/spi.h b/os/dev/spi.h
index b7114717f..9dda05b8e 100644
--- a/os/dev/spi.h
+++ b/os/dev/spi.h
@@ -323,25 +323,6 @@ spi_status_t spi_arch_transfer(const spi_device_t *dev,
                                uint8_t *buf, int rlen,
                                int ignore_len);
 
-/**
- * \brief Selects an SPI device
- * \param dev An SPI device configuration that specifies the CS pin.
- * \return SPI return code
- *
- * Clears the CS pin. It should work only if the device has already
- * locked the SPI controller.
- */
-spi_status_t spi_arch_select(const spi_device_t *dev);
-
-/**
- * \brief Deselects an SPI device
- * \param dev An SPI device configuration that specifies the CS pin.
- * \return SPI return code
- *
- * Set the CS pin. Locking the SPI controller is not needed.
- */
-spi_status_t spi_arch_deselect(const spi_device_t *dev);
-
 #endif /* SPI_H_ */
 /*---------------------------------------------------------------------------*/
 /**
diff --git a/os/net/app-layer/mqtt/mqtt.c b/os/net/app-layer/mqtt/mqtt.c
index 46a542c3f..9571244d8 100644
--- a/os/net/app-layer/mqtt/mqtt.c
+++ b/os/net/app-layer/mqtt/mqtt.c
@@ -872,6 +872,7 @@ parse_publish_vhdr(struct mqtt_connection *conn,
 
   /* Read out topic length */
   if(conn->in_packet.topic_len_received == 0) {
+    conn->in_packet.topic_pos = 0;
     conn->in_packet.topic_len = (input_data_ptr[(*pos)++] << 8);
     conn->in_packet.byte_counter++;
     if(*pos >= input_data_len) {
@@ -880,7 +881,11 @@ parse_publish_vhdr(struct mqtt_connection *conn,
     conn->in_packet.topic_len |= input_data_ptr[(*pos)++];
     conn->in_packet.byte_counter++;
     conn->in_packet.topic_len_received = 1;
-
+    /* Abort if topic is longer than our topic buffer */
+    if(conn->in_packet.topic_len > MQTT_MAX_TOPIC_LENGTH) {
+      DBG("MQTT - topic too long %u/%u\n", conn->in_packet.topic_len, MQTT_MAX_TOPIC_LENGTH);
+      return;
+    }
     DBG("MQTT - Read PUBLISH topic len %i\n", conn->in_packet.topic_len);
     /* WARNING: Check here if TOPIC fits in payload area, otherwise error */
   }
diff --git a/os/net/mac/tsch/tsch.h b/os/net/mac/tsch/tsch.h
index 8590dcb38..db23b4851 100644
--- a/os/net/mac/tsch/tsch.h
+++ b/os/net/mac/tsch/tsch.h
@@ -158,7 +158,7 @@ extern uint8_t tsch_current_channel;
 extern uint8_t tsch_hopping_sequence[TSCH_HOPPING_SEQUENCE_MAX_LEN];
 extern struct tsch_asn_divisor_t tsch_hopping_sequence_length;
 /* TSCH timeslot timing (in micro-second) */
-uint16_t tsch_timing_us[tsch_ts_elements_count];
+extern uint16_t tsch_timing_us[tsch_ts_elements_count];
 /* TSCH timeslot timing (in rtimer ticks) */
 extern rtimer_clock_t tsch_timing[tsch_ts_elements_count];
 /* Statistics on the current session */
diff --git a/tests/01-compile-base/Makefile b/tests/01-compile-base/Makefile
index e51ff523b..09f89418d 100644
--- a/tests/01-compile-base/Makefile
+++ b/tests/01-compile-base/Makefile
@@ -24,6 +24,8 @@ rpl-border-router/sky \
 slip-radio/sky \
 libs/ipv6-hooks/sky \
 nullnet/native \
+nullnet/sky \
+nullnet/sky:MAKE_MAC=MAKE_MAC_TSCH \
 mqtt-client/native \
 coap/coap-example-client/native \
 coap/coap-example-server/native \
diff --git a/tests/02-compile-arm-ports-01/Makefile b/tests/02-compile-arm-ports-01/Makefile
index 2ec2ce443..aaebab164 100644
--- a/tests/02-compile-arm-ports-01/Makefile
+++ b/tests/02-compile-arm-ports-01/Makefile
@@ -89,6 +89,8 @@ platform-specific/cc2538-common/pka/cc2538dk \
 hello-world/cc2538dk \
 rpl-border-router/cc2538dk \
 rpl-border-router/cc2538dk:MAKE_ROUTING=MAKE_ROUTING_RPL_CLASSIC \
+6tisch/simple-node/cc2538dk \
+6tisch/simple-node/cc2538dk:MAKE_WITH_SECURITY=1,MAKE_WITH_ORCHESTRA=1 \
 hello-world/nrf52dk \
 platform-specific/nrf52dk/coap-demo/coap-server/nrf52dk \
 platform-specific/nrf52dk/coap-demo/coap-client/nrf52dk:SERVER_IPV6_EP=ffff \
diff --git a/tests/03-compile-arm-ports-02/Makefile b/tests/03-compile-arm-ports-02/Makefile
index 190d36e4d..655967e1b 100644
--- a/tests/03-compile-arm-ports-02/Makefile
+++ b/tests/03-compile-arm-ports-02/Makefile
@@ -28,6 +28,7 @@ storage/antelope-shell/zoul \
 6tisch/simple-node/zoul:MAKE_WITH_ORCHESTRA=1 \
 6tisch/simple-node/zoul:MAKE_WITH_SECURITY=1 \
 libs/logging/zoul \
+libs/logging/zoul:MAKE_MAC=MAKE_MAC_TSCH \
 6tisch/etsi-plugtest-2017/zoul:BOARD=remote \
 6tisch/6p-packet/zoul \
 6tisch/sixtop/zoul \
@@ -68,6 +69,8 @@ libs/ipv6-hooks/openmote-cc2538 \
 libs/shell/openmote-cc2538 \
 libs/simple-energest/openmote-cc2538 \
 libs/deployment/openmote-cc2538 \
+6tisch/simple-node/openmote-cc2538 \
+6tisch/simple-node/openmote-cc2538:MAKE_WITH_SECURITY=1,MAKE_WITH_ORCHESTRA=1 \
 
 TOOLS=
 
diff --git a/tests/compile-all/build.sh b/tests/compile-all/build.sh
index fcbbd7bd7..81441816e 100755
--- a/tests/compile-all/build.sh
+++ b/tests/compile-all/build.sh
@@ -40,17 +40,21 @@
 # To invoke the building for a specific platform, run:
 # $ PLATFORMS=zoul ./build.sh
 #
+CONTIKI_NG_TOP_DIR="../.."
+EXAMPLES_DIR=$CONTIKI_NG_TOP_DIR/examples
 
 if [[ "$PLATFORMS" == "" ]]
 then
-    PLATFORMS=`ls ../../arch/platform`
+    PLATFORMS=`ls $CONTIKI_NG_TOP_DIR/arch/platform`
 fi
 
 if [[ "$MAKEFILES" == "" ]]
 then
-    MAKEFILES=`find ../../examples/ -name Makefile`
+    MAKEFILES=`find $EXAMPLES_DIR -name Makefile`
 fi
 
+HELLO_WORLD=$EXAMPLES_DIR/hello-world
+
 # Set the make goal the first argument of the script or to "all" if called w/o arguments
 if [[ $# -gt 0 ]]
 then
@@ -97,22 +101,14 @@ do
         continue
     fi
 
-    if [[ "$platform" == "srf06-cc26xx" ]]
+    # Detect all boards for the current platform by calling
+    # make TARGET=$platform boards
+    # in the hello-world dir.
+    BOARDS=`make -s -C $HELLO_WORLD TARGET=$platform boards \
+            | grep -v "no boards" | rev | cut -f3- -d" " | rev`
+
+    if [[ -z $BOARDS ]]
     then
-        # srf06-cc26xx has multiple boards
-        BOARDS="srf06/cc26xx srf06/cc13xx launchpad/cc2650 launchpad/cc1310 launchpad/cc1350 sensortag/cc2650 sensortag/cc1350"
-    elif [[ "$platform" == "simplelink" ]]
-    then
-        # SimpleLink has multiple boards
-        BOARDS="launchpad/cc1310 launchpad/cc1350 launchpad/cc1350-4 launchpad/cc2650 \
-                sensortag/cc1350 sensortag/cc2650 srf06/cc13x0 srf06/cc26x0 \
-                launchpad/cc1312r1 launchpad/cc1352r1 launchpad/cc1352p1 launchpad/cc1352p-2 launchpad/cc1352p-4 launchpad/cc26x2r1"
-    elif [[ "$platform" == "zoul" ]]
-    then
-        # Zoul has multiple boards
-        BOARDS="remote-reva remote-revb firefly-reva firefly orion"
-    else
-        # Other platforms have just a single board
         BOARDS="default"
     fi