diff --git a/conf/modules/airspeed_amsys.xml b/conf/modules/airspeed_amsys.xml
index 000b2a424b..9e7c4b5cf1 100644
--- a/conf/modules/airspeed_amsys.xml
+++ b/conf/modules/airspeed_amsys.xml
@@ -34,7 +34,7 @@
   <event fun="AirspeedAmsysEvent()"/>
 
   <makefile>
-    <configure name="AIRSPEED_AMSYS_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="AIRSPEED_AMSYS_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(AIRSPEED_AMSYS_I2C_DEV_UPPER)"/>
     <define name="AIRSPEED_AMSYS_I2C_DEV" value="$(AIRSPEED_AMSYS_I2C_DEV_LOWER)"/>
     <file name="airspeed_amsys.c"/>
diff --git a/conf/modules/airspeed_ets.xml b/conf/modules/airspeed_ets.xml
index 55ad1bf922..a32ec8534d 100644
--- a/conf/modules/airspeed_ets.xml
+++ b/conf/modules/airspeed_ets.xml
@@ -36,7 +36,7 @@
   <event fun="AirspeedEtsEvent()"/>
 
   <makefile>
-    <configure name="AIRSPEED_ETS_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="AIRSPEED_ETS_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(AIRSPEED_ETS_I2C_DEV_UPPER)"/>
     <define name="AIRSPEED_ETS_I2C_DEV" value="$(AIRSPEED_ETS_I2C_DEV_LOWER)"/>
     <file name="airspeed_ets.c"/>
diff --git a/conf/modules/baro_amsys.xml b/conf/modules/baro_amsys.xml
index f4414a228f..e080cf9944 100644
--- a/conf/modules/baro_amsys.xml
+++ b/conf/modules/baro_amsys.xml
@@ -30,7 +30,7 @@
   <event fun="BaroAmsysEvent()"/>
 
   <makefile target="ap">
-    <configure name="BARO_AMSYS_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="BARO_AMSYS_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(BARO_AMSYS_I2C_DEV_UPPER)"/>
     <define name="BARO_AMSYS_I2C_DEV" value="$(BARO_AMSYS_I2C_DEV_LOWER)"/>
     <file name="baro_amsys.c"/>
diff --git a/conf/modules/baro_bmp.xml b/conf/modules/baro_bmp.xml
index 457598c436..98f99149b0 100644
--- a/conf/modules/baro_bmp.xml
+++ b/conf/modules/baro_bmp.xml
@@ -13,7 +13,7 @@
   <periodic fun="baro_bmp_periodic()" freq="15"/>
   <event fun="baro_bmp_event()"/>
   <makefile target="ap">
-    <configure name="BMP_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="BMP_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(BMP_I2C_DEV_UPPER)"/>
     <define name="BMP_I2C_DEV" value="$(BMP_I2C_DEV_LOWER)"/>
     <file name="baro_bmp.c"/>
diff --git a/conf/modules/baro_ets.xml b/conf/modules/baro_ets.xml
index 1e155c60a0..27c2647525 100644
--- a/conf/modules/baro_ets.xml
+++ b/conf/modules/baro_ets.xml
@@ -34,7 +34,7 @@
   <event fun="BaroEtsEvent()"/>
 
   <makefile target="ap">
-    <configure name="BARO_ETS_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="BARO_ETS_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(BARO_ETS_I2C_DEV_UPPER)"/>
     <define name="BARO_ETS_I2C_DEV" value="$(BARO_ETS_I2C_DEV_LOWER)"/>
     <file name="baro_ets.c"/>
diff --git a/conf/modules/baro_hca.xml b/conf/modules/baro_hca.xml
index a6fe0bbfa0..db27c37d59 100644
--- a/conf/modules/baro_hca.xml
+++ b/conf/modules/baro_hca.xml
@@ -14,7 +14,7 @@
   <event fun="BaroHcaEvent()"/>
 
   <makefile target="ap">
-    <configure name="BARO_HCA_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="BARO_HCA_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(BARO_HCA_I2C_DEV_UPPER)"/>
     <define name="BARO_HCA_I2C_DEV" value="$(BARO_HCA_I2C_DEV_LOWER)"/>
     <file name="baro_hca.c"/>
diff --git a/conf/modules/baro_ms5611_i2c.xml b/conf/modules/baro_ms5611_i2c.xml
index 189eb8192d..45a01b83b3 100644
--- a/conf/modules/baro_ms5611_i2c.xml
+++ b/conf/modules/baro_ms5611_i2c.xml
@@ -17,7 +17,7 @@
   <periodic fun="baro_ms5611_periodic_check()" freq="40"/>
   <event fun="baro_ms5611_event()"/>
   <makefile target="ap">
-    <configure name="MS5611_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="MS5611_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(MS5611_I2C_DEV_UPPER)"/>
     <define name="MS5611_I2C_DEV" value="$(MS5611_I2C_DEV_LOWER)"/>
     <file name="baro_ms5611_i2c.c"/>
diff --git a/conf/modules/baro_ms5611_spi.xml b/conf/modules/baro_ms5611_spi.xml
index 2739d55496..f8df1fec16 100644
--- a/conf/modules/baro_ms5611_spi.xml
+++ b/conf/modules/baro_ms5611_spi.xml
@@ -18,8 +18,8 @@
   <periodic fun="baro_ms5611_periodic_check()" freq="40"/>
   <event fun="baro_ms5611_event()"/>
   <makefile target="ap">
-    <configure name="MS5611_SPI_DEV" value="spi1" default="TRUE" case="upper|lower"/>
-    <configure name="MS5611_SLAVE_IDX" value="spi_slave0" default="TRUE" case="upper|lower"/>
+    <configure name="MS5611_SPI_DEV" default="spi1" case="upper|lower"/>
+    <configure name="MS5611_SLAVE_IDX" default="spi_slave0" case="upper|lower"/>
     <raw>
       include $(CFG_SHARED)/spi_master.makefile
     </raw>
diff --git a/conf/modules/baro_scp_i2c.xml b/conf/modules/baro_scp_i2c.xml
index 227d5a1066..4320efb88a 100644
--- a/conf/modules/baro_scp_i2c.xml
+++ b/conf/modules/baro_scp_i2c.xml
@@ -13,7 +13,7 @@
   <periodic fun="baro_scp_periodic()" freq="1.8"/>
   <event fun="baro_scp_event()"/>
   <makefile target="ap">
-    <configure name="SCP_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="SCP_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(SCP_I2C_DEV_UPPER)"/>
     <define name="SCP_I2C_DEV" value="$(SCP_I2C_DEV_LOWER)"/>
     <file name="baro_scp_i2c.c"/>
diff --git a/conf/modules/digital_cam_i2c.xml b/conf/modules/digital_cam_i2c.xml
index 906e753b0f..f52b6ac0f6 100644
--- a/conf/modules/digital_cam_i2c.xml
+++ b/conf/modules/digital_cam_i2c.xml
@@ -27,7 +27,7 @@
   <datalink message="PAYLOAD_COMMAND" fun="ParseCameraCommand()"/>
 
   <makefile target="ap">
-    <configure name="ATMEGA_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="ATMEGA_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(ATMEGA_I2C_DEV_UPPER)"/>
     <define name="ATMEGA_I2C_DEV" value="$(ATMEGA_I2C_DEV_LOWER)"/>
     <file name="atmega_i2c_cam_ctrl.c"/>
diff --git a/conf/modules/direct_memory_logger.xml b/conf/modules/direct_memory_logger.xml
index f4c74b9022..e41bed3e65 100644
--- a/conf/modules/direct_memory_logger.xml
+++ b/conf/modules/direct_memory_logger.xml
@@ -27,9 +27,9 @@
   <periodic fun="direct_memory_logger_periodic()" autorun="TRUE"/>
 
   <makefile target="ap">
-    <configure name="DM_LOG_UART" value="uart1" default="TRUE" case="upper|lower"/>
-    <configure name="DM_LOG_SPI_DEV" value="spi2" default="TRUE" case="upper|lower"/>
-    <configure name="DM_LOG_SPI_SLAVE_IDX" value="spi_slave1" default="TRUE" case="upper|lower"/>
+    <configure name="DM_LOG_UART" default="uart1" case="upper|lower"/>
+    <configure name="DM_LOG_SPI_DEV" default="spi2" case="upper|lower"/>
+    <configure name="DM_LOG_SPI_SLAVE_IDX" default="spi_slave1" case="upper|lower"/>
     <raw>
       include $(CFG_SHARED)/spi_master.makefile
     </raw>
diff --git a/conf/modules/ezcurrent.xml b/conf/modules/ezcurrent.xml
index 5780d49103..1246897cd7 100644
--- a/conf/modules/ezcurrent.xml
+++ b/conf/modules/ezcurrent.xml
@@ -14,7 +14,7 @@
   <event fun="ezcurrent_read_event()"/>
 
   <makefile target="ap">
-    <configure name="EZCURRENT_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="EZCURRENT_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(EZCURRENT_I2C_DEV_UPPER)"/>
     <define name="EZCURRENT_I2C_DEV" value="$(EZCURRENT_I2C_DEV_LOWER)"/>
     <file name="ezcurrent.c"/>
diff --git a/conf/modules/generic_com.xml b/conf/modules/generic_com.xml
index 1eb9386a3f..ed27bd34e8 100644
--- a/conf/modules/generic_com.xml
+++ b/conf/modules/generic_com.xml
@@ -16,7 +16,7 @@
   <periodic fun="generic_com_periodic()" period="180" start="start_com()" stop="stop_com()" autorun="TRUE"/>
   <event fun="generic_com_event()"/>
   <makefile>
-    <configure name="GENERIC_COM_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="GENERIC_COM_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(GENERIC_COM_I2C_DEV_UPPER)"/>
     <define name="GENERIC_COM_I2C_DEV" value="$(GENERIC_COM_I2C_DEV_LOWER)"/>
     <file name="generic_com.c"/>
diff --git a/conf/modules/gps_ublox.xml b/conf/modules/gps_ublox.xml
index a082a92d26..0ab7093e28 100644
--- a/conf/modules/gps_ublox.xml
+++ b/conf/modules/gps_ublox.xml
@@ -25,7 +25,7 @@
     <define name="USE_$(GPS_PORT_UPPER)"/>
     <define name="GPS_LINK" value="$(GPS_PORT_LOWER)"/>
     <define name="$(GPS_PORT_UPPER)_BAUD" value="$(GPS_BAUD)"/>
-    <configure name="GPS_LED" value="none" default="TRUE"/>
+    <configure name="GPS_LED" default="none"/>
     <define name="GPS_LED" value="$(GPS_LED)" cond="ifneq ($(GPS_LED),none)"/>
     <raw>
       ap.CFLAGS += -DGPS_TYPE_H=\"subsystems/gps/gps_ubx.h\"
diff --git a/conf/modules/hott_telemetry.xml b/conf/modules/hott_telemetry.xml
index e5c3feef3a..dba6bb0752 100644
--- a/conf/modules/hott_telemetry.xml
+++ b/conf/modules/hott_telemetry.xml
@@ -25,11 +25,11 @@
 
   <makefile target="ap">
     <file name="hott.c"/>
-    <configure name="HOTT_PORT" value="uart1" default="TRUE" case="upper|lower"/>
-    <configure name="HOTT_SIM_EAM_SENSOR" value="1" default="TRUE"/>
-    <configure name="HOTT_SIM_GAM_SENSOR" value="0" default="TRUE"/>
-    <configure name="HOTT_SIM_GPS_SENSOR" value="0" default="TRUE"/>
-    <configure name="HOTT_SIM_VARIO_SENSOR" value="0" default="TRUE"/>
+    <configure name="HOTT_PORT" default="uart1" case="upper|lower"/>
+    <configure name="HOTT_SIM_EAM_SENSOR" default="1"/>
+    <configure name="HOTT_SIM_GAM_SENSOR" default="0"/>
+    <configure name="HOTT_SIM_GPS_SENSOR" default="0"/>
+    <configure name="HOTT_SIM_VARIO_SENSOR" default="0"/>
     <define name="HOTT_PORT" value="$(HOTT_PORT_LOWER)"/>
     <define name="USE_$(HOTT_PORT_UPPER)"/>
     <define name="$(HOTT_PORT_UPPER)_BAUD" value="B19200"/>
diff --git a/conf/modules/humid_htm_b71.xml b/conf/modules/humid_htm_b71.xml
index 7f90242ea2..d0b2b7b067 100644
--- a/conf/modules/humid_htm_b71.xml
+++ b/conf/modules/humid_htm_b71.xml
@@ -13,7 +13,7 @@
   <periodic fun="humid_htm_read()"  freq="4" delay="14"/>
   <event fun="humid_htm_event()"/>
   <makefile target="ap">
-    <configure name="HTM_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="HTM_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(HTM_I2C_DEV_UPPER)"/>
     <define name="HTM_I2C_DEV" value="$(HTM_I2C_DEV_LOWER)"/>
     <file name="humid_htm_b71.c"/>
diff --git a/conf/modules/imu_mpu9250.xml b/conf/modules/imu_mpu9250.xml
index 4b9579265b..e47113d529 100644
--- a/conf/modules/imu_mpu9250.xml
+++ b/conf/modules/imu_mpu9250.xml
@@ -17,7 +17,7 @@
   <periodic fun="imu_mpu9250_report()" freq="10" autorun="TRUE"/>
   <event fun="imu_mpu9250_event()"/>
   <makefile>
-    <configure name="IMU_MPU9250_I2C_DEV" value="i2c1" default="TRUE" case="upper|lower"/>
+    <configure name="IMU_MPU9250_I2C_DEV" default="i2c1" case="upper|lower"/>
     <define name="USE_$(IMU_MPU9250_I2C_DEV_UPPER)"/>
     <define name="IMU_MPU9250_I2C_DEV" value="$(IMU_MPU9250_I2C_DEV_LOWER)"/>
     <file name="imu_mpu9250.c"/>
diff --git a/conf/modules/ins_vn100.xml b/conf/modules/ins_vn100.xml
index f2a77bcd1f..5e5959bcb0 100644
--- a/conf/modules/ins_vn100.xml
+++ b/conf/modules/ins_vn100.xml
@@ -15,8 +15,8 @@
   <periodic fun="vn100_report_task()" freq="4"/>
   <event fun="vn100_event_task()"/>
   <makefile>
-    <configure name="VN100_SPI_DEV" value="spi1" default="TRUE" case="upper|lower"/>
-    <configure name="VN100_SLAVE_IDX" value="spi_slave0" default="TRUE" case="upper|lower"/>
+    <configure name="VN100_SPI_DEV" default="spi1" case="upper|lower"/>
+    <configure name="VN100_SLAVE_IDX" default="spi_slave0" case="upper|lower"/>
     <raw>
       include $(CFG_SHARED)/spi_master.makefile
     </raw>
diff --git a/conf/modules/logger_dataflash.xml b/conf/modules/logger_dataflash.xml
index fa1b606265..14f2ff7ee8 100644
--- a/conf/modules/logger_dataflash.xml
+++ b/conf/modules/logger_dataflash.xml
@@ -39,9 +39,9 @@ For more informations on how to use this module you can refer to the wiki : http
   <periodic fun="high_speed_logger_direct_memory_periodic()" autorun="TRUE"/>
   <makefile>
 
-    <configure name="HS_LOG_UART" value="uart3" default="TRUE" case="upper|lower"/>
-    <configure name="HS_LOG_SPI" value="spi1" default="TRUE" case="upper|lower"/>
-    <configure name="HS_LOG_SPI_SLAVE" value="spi_slave1" default="TRUE" case="upper|lower"/>
+    <configure name="HS_LOG_UART" default="uart3" case="upper|lower"/>
+    <configure name="HS_LOG_SPI" default="spi1" case="upper|lower"/>
+    <configure name="HS_LOG_SPI_SLAVE" default="spi_slave1" case="upper|lower"/>
 
     <define name="SPI_MASTER" value="1" />
     <define name="USE_$(HS_LOG_SPI_UPPER)" value="1" />
diff --git a/conf/modules/logger_sd_spi_direct.xml b/conf/modules/logger_sd_spi_direct.xml
index 1c35c84f49..44bf65c18b 100644
--- a/conf/modules/logger_sd_spi_direct.xml
+++ b/conf/modules/logger_sd_spi_direct.xml
@@ -38,10 +38,10 @@ Do not use start/stop functionality of the module, the module is not intended to
   <datalink message="SETTING" fun="sdlogger_spi_direct_command()"/>
   <makefile target="ap">
 
-    <configure name="SDLOGGER_DIRECT_SPI" value="spi2" default="TRUE" case="upper|lower"/>
-    <configure name="SDLOGGER_DIRECT_SPI_SLAVE" value="spi_slave2" default="TRUE" case="upper|lower"/>
-    <configure name="SDLOGGER_DIRECT_CONTROL_SWITCH" value="RADIO_AUX2" default="TRUE"/>
-    <configure name="LOGGER_LED" value="none" default="TRUE"/>
+    <configure name="SDLOGGER_DIRECT_SPI" default="spi2" case="upper|lower"/>
+    <configure name="SDLOGGER_DIRECT_SPI_SLAVE" default="spi_slave2" case="upper|lower"/>
+    <configure name="SDLOGGER_DIRECT_CONTROL_SWITCH" default="RADIO_AUX2"/>
+    <configure name="LOGGER_LED" default="none"/>
     <define name="LOGGER_LED" value="$(LOGGER_LED)" cond="ifneq ($(LOGGER_LED),none)"/>
     <raw>
         include $(CFG_SHARED)/sdlog.makefile
diff --git a/conf/modules/logger_spi_link.xml b/conf/modules/logger_spi_link.xml
index fea247d899..4138edb78b 100644
--- a/conf/modules/logger_spi_link.xml
+++ b/conf/modules/logger_spi_link.xml
@@ -12,8 +12,8 @@
   <init fun="high_speed_logger_spi_link_init()"/>
   <periodic fun="high_speed_logger_spi_link_periodic()" autorun="TRUE"/>
   <makefile target="ap">
-    <configure name="HS_LOG_SPI_DEV" value="spi1" default="TRUE" case="upper|lower"/>
-    <configure name="HS_LOG_SPI_SLAVE_IDX" value="spi_slave1" default="TRUE" case="upper|lower"/>
+    <configure name="HS_LOG_SPI_DEV" default="spi1" case="upper|lower"/>
+    <configure name="HS_LOG_SPI_SLAVE_IDX" default="spi_slave1" case="upper|lower"/>
     <raw>
       include $(CFG_SHARED)/spi_master.makefile
     </raw>
diff --git a/conf/modules/mag_hmc5843.xml b/conf/modules/mag_hmc5843.xml
index c18fed99b5..0f61d02028 100644
--- a/conf/modules/mag_hmc5843.xml
+++ b/conf/modules/mag_hmc5843.xml
@@ -12,7 +12,7 @@
   <periodic fun="hmc5843_module_periodic()" freq="60"/>
   <event fun="hmc5843_module_event()"/>
   <makefile>
-    <configure name="HMC5843_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="HMC5843_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(HMC5843_I2C_DEV_UPPER)"/>
     <define name="HMC5843_I2C_DEV" value="$(HMC5843_I2C_DEV_LOWER)"/>
     <file name="mag_hmc5843.c"/>
diff --git a/conf/modules/mavlink.xml b/conf/modules/mavlink.xml
index 6cfb20d605..a78685bca9 100644
--- a/conf/modules/mavlink.xml
+++ b/conf/modules/mavlink.xml
@@ -20,7 +20,7 @@
     <file name="mission_manager.c" dir="modules/datalink/missionlib"/>
     <file name="waypoints.c" dir="modules/datalink/missionlib"/>
     <file name="blocks.c" dir="modules/datalink/missionlib"/>
-    <configure name="MAVLINK_PORT" value="uart1" default="TRUE" case="upper|lower"/>
+    <configure name="MAVLINK_PORT" default="uart1" case="upper|lower"/>
     <raw>
       ifneq (,$(findstring usb,$(MAVLINK_PORT_LOWER)))
       ap.CFLAGS += -DUSE_USB_SERIAL
diff --git a/conf/modules/osd_max7456.xml b/conf/modules/osd_max7456.xml
index abdca90edf..ab69dcf63e 100644
--- a/conf/modules/osd_max7456.xml
+++ b/conf/modules/osd_max7456.xml
@@ -13,8 +13,8 @@
   <periodic fun="max7456_periodic()" freq="20" autorun="TRUE"/>
   <event fun="max7456_event()"/>
   <makefile target="ap">
-    <configure name="MAX7456_SPI_DEV" value="spi2" default="TRUE" case="upper|lower"/>
-    <configure name="MAX7456_SLAVE_IDX" value="spi_slave2" default="TRUE" case="upper|lower"/>
+    <configure name="MAX7456_SPI_DEV" default="spi2" case="upper|lower"/>
+    <configure name="MAX7456_SLAVE_IDX" default="spi_slave2" case="upper|lower"/>
     <raw>
       include $(CFG_SHARED)/spi_master.makefile
     </raw>
diff --git a/conf/modules/stereocam_droplet.xml b/conf/modules/stereocam_droplet.xml
index 7cea059ccf..356317d11f 100644
--- a/conf/modules/stereocam_droplet.xml
+++ b/conf/modules/stereocam_droplet.xml
@@ -11,9 +11,9 @@
   <periodic fun="stereocam_droplet_periodic()" freq="20" autorun="TRUE"/>
   <makefile target="ap">
     <file name="droplet/stereocam_droplet.c"/>
-    <configure name="STEREO_UART" value="uart1" default="TRUE" case="upper|lower"/>
-    <configure name="STEREO_BAUD" value="B9600" default="TRUE"/>
-    <configure name="STEREO_LED" value="3" default="TRUE"/>
+    <configure name="STEREO_UART" default="uart1" case="upper|lower"/>
+    <configure name="STEREO_BAUD" default="B9600"/>
+    <configure name="STEREO_LED" default="3"/>
     <define name="USE_$(STEREO_UART_UPPER)"/>
     <define name="STEREO_UART" value="$(STEREO_UART_LOWER)"/>
     <define name="$(STEREO_UART_UPPER)_BAUD" value="$(STEREO_BAUD)"/>
diff --git a/conf/modules/stereocam_nav_line_avoid.xml b/conf/modules/stereocam_nav_line_avoid.xml
index 09b8790d9e..3bcb6ff318 100644
--- a/conf/modules/stereocam_nav_line_avoid.xml
+++ b/conf/modules/stereocam_nav_line_avoid.xml
@@ -14,9 +14,9 @@
   <periodic fun="stereo_avoid_run()" freq="20" autorun="TRUE"/>
 
   <makefile>
-    <configure name="STEREO_UART" value="uart1" default="TRUE" case="upper|lower"/>
-    <configure name="STEREO_BAUD" value="B9600" default="TRUE"/>
-    <configure name="STEREO_LED" value="3" default="TRUE"/>
+    <configure name="STEREO_UART" default="uart1" case="upper|lower"/>
+    <configure name="STEREO_BAUD" default="B9600"/>
+    <configure name="STEREO_LED" default="3"/>
     <define name="USE_$(STEREO_UART_UPPER)"/>
     <define name="STEREO_UART" value="$(STEREO_UART_LOWER)"/>
     <define name="$(STEREO_UART_UPPER)_BAUD" value="$(STEREO_BAUD)"/>
diff --git a/conf/modules/temp_temod.xml b/conf/modules/temp_temod.xml
index d0f9fec30d..f6689d7477 100644
--- a/conf/modules/temp_temod.xml
+++ b/conf/modules/temp_temod.xml
@@ -14,7 +14,7 @@
   <periodic fun="temod_periodic()" freq="8"/>
   <event fun="temod_event()"/>
   <makefile target="ap">
-    <configure name="TEMOD_I2C_DEV" value="i2c0" default="TRUE" case="upper|lower"/>
+    <configure name="TEMOD_I2C_DEV" default="i2c0" case="upper|lower"/>
     <define name="USE_$(TEMOD_I2C_DEV_UPPER)"/>
     <define name="TEMOD_I2C_DEV" value="$(TEMOD_I2C_DEV_LOWER)"/>
     <file name="temp_temod.c"/>
diff --git a/conf/modules/uart_drop.xml b/conf/modules/uart_drop.xml
index 6443cd47d5..97ab897552 100644
--- a/conf/modules/uart_drop.xml
+++ b/conf/modules/uart_drop.xml
@@ -9,8 +9,8 @@
   </header>
   <makefile>
     <file name="uart_drop.c"/>
-    <configure name="UART_DROP_PORT" value="uart1" default="TRUE" case="upper|lower"/>
-    <configure name="UART_DROP_BAUD" value="B115200" default="TRUE"/>
+    <configure name="UART_DROP_PORT" default="uart1" case="upper|lower"/>
+    <configure name="UART_DROP_BAUD" default="B115200"/>
     <define name="UART_DROP_PORT" value="$(UART_DROP_PORT_LOWER)"/>
     <define name="USE_$(UART_DROP_PORT_UPPER)"/>
     <define name="$(UART_DROP_PORT_UPPER)_BAUD" value="$(UART_DROP_BAUD)"/>
diff --git a/sw/tools/generators/gen_aircraft.ml b/sw/tools/generators/gen_aircraft.ml
index ee7db97a28..43af402bbb 100644
--- a/sw/tools/generators/gen_aircraft.ml
+++ b/sw/tools/generators/gen_aircraft.ml
@@ -59,11 +59,13 @@ let configure_xml2mk = fun f xml ->
   (* all makefiles variables are forced to uppercase *)
   let name = String.uppercase (ExtXml.attrib xml "name")
   and value = ExtXml.attrib_or_default xml "value" ""
-  and default = if String.lowercase (ExtXml.attrib_or_default xml "default" "") = "true" then "?" else ""
+  and default = ExtXml.attrib_or_default xml "default" ""
   and case = ExtXml.attrib_or_default xml "case" "" in
   (* Only print variable if value is not empty *)
   if String.length value > 0 then
-    fprintf f "%s %s= %s\n" name default value;
+    fprintf f "%s = %s\n" name value
+  else if String.length default > 0 then
+    fprintf f "%s ?= %s\n" name default;
   (* also providing lower and upper case version on request *)
   if Str.string_match (Str.regexp ".*lower.*") case 0 then
     fprintf f "%s_LOWER = $(shell echo $(%s) | tr A-Z a-z)\n" name name;