diff --git a/libraries/AP_Compass/AP_Compass.cpp b/libraries/AP_Compass/AP_Compass.cpp
index e540077784..83cf1b0a64 100644
--- a/libraries/AP_Compass/AP_Compass.cpp
+++ b/libraries/AP_Compass/AP_Compass.cpp
@@ -872,85 +872,8 @@ void Compass::_detect_backends(void)
         break;
     }
 
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_BH
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR)));
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(0));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_BBBMINI
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), true, ROTATION_NONE));
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(0, ROTATION_NONE));
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(1, ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_NAVIO2
-    ADD_BACKEND(DRIVER_LSM9DS1, AP_Compass_LSM9DS1::probe(hal.spi->get_device("lsm9ds1_m"), ROTATION_ROLL_180));
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(0, ROTATION_NONE));
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), true));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_NAVIO
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(0, ROTATION_NONE));
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), true, ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_OCPOC_ZYNQ
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), ROTATION_NONE));
-    ADD_BACKEND(DRIVER_AK8963,AP_Compass_AK8963::probe_mpu9250(0, ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_EDGE
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), true, ROTATION_NONE));
-#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF || \
-      CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_ERLEBRAIN2 || \
-      CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXFMINI
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(0, ROTATION_NONE));
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), true, ROTATION_NONE));
-#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BLUE
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(GET_I2C_DEVICE(HAL_COMPASS_AK8963_I2C_BUS, HAL_COMPASS_AK8963_I2C_ADDR), ROTATION_NONE));
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), true, ROTATION_NONE));
-#elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_POCKET
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(0, ROTATION_NONE));
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), true, ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_AK8963_MPU9250
-#ifndef HAL_COMPASS_AK8963_MPU9250_ROTATION
-#define HAL_COMPASS_AK8963_MPU9250_ROTATION ROTATION_NONE
-#endif
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(0, HAL_COMPASS_AK8963_MPU9250_ROTATION));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_HMC5843
-#ifndef HAL_COMPASS_HMC5843_ROTATION
-# define HAL_COMPASS_HMC5843_ROTATION ROTATION_NONE
-#endif
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR),
-                                                          false, HAL_COMPASS_HMC5843_ROTATION));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_HMC5843_MPU6000
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe_mpu6000(ROTATION_NONE));
-#elif  HAL_COMPASS_DEFAULT == HAL_COMPASS_AK8963_I2C
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe(GET_I2C_DEVICE(HAL_COMPASS_AK8963_I2C_BUS, HAL_COMPASS_AK8963_I2C_ADDR), ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_AK8963_MPU9250_I2C
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(GET_I2C_DEVICE(HAL_COMPASS_AK8963_I2C_BUS, HAL_COMPASS_AK8963_I2C_ADDR), ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_AERO
-    ADD_BACKEND(DRIVER_BMM150, AP_Compass_BMM150::probe(GET_I2C_DEVICE(HAL_COMPASS_BMM150_I2C_BUS, HAL_COMPASS_BMM150_I2C_ADDR), ROTATION_NONE));
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), true, ROTATION_NONE));
-    ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(GET_I2C_DEVICE(HAL_COMPASS_IST8310_I2C_BUS, HAL_COMPASS_IST8310_I2C_ADDR),
-                                                          true, ROTATION_PITCH_180_YAW_90));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_LIS3MDL
-    ADD_BACKEND(DRIVER_LIS3MDL, AP_Compass_LIS3MDL::probe(hal.spi->get_device(HAL_COMPASS_LIS3MDL_NAME), false, ROTATION_ROLL_180_YAW_90));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_MAG3110                
-    ADD_BACKEND(DRIVER_MAG3110, AP_Compass_MAG3110::probe(GET_I2C_DEVICE(HAL_MAG3110_I2C_BUS, HAL_MAG3110_I2C_ADDR), ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_IST8310
-    ADD_BACKEND(DRIVER_IST8310, AP_Compass_IST8310::probe(GET_I2C_DEVICE(HAL_COMPASS_IST8310_I2C_BUS, HAL_COMPASS_IST8310_I2C_ADDR),
-                                                           true, ROTATION_PITCH_180_YAW_90));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_QMC5883L
-    ADD_BACKEND(DRIVER_QMC5883L, AP_Compass_QMC5883L::probe(GET_I2C_DEVICE(1, HAL_COMPASS_QMC5883L_I2C_ADDR),
-                                                           true, HAL_COMPASS_QMC5883L_ORIENTATION_EXTERNAL));
-    ADD_BACKEND(DRIVER_QMC5883L, AP_Compass_QMC5883L::probe(GET_I2C_DEVICE(0, HAL_COMPASS_QMC5883L_I2C_ADDR),
-                                                           false, HAL_COMPASS_QMC5883L_ORIENTATION_INTERNAL));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_LIS3MDL_I2C
-    FOREACH_I2C(i) {
-        ADD_BACKEND(DRIVER_LIS3MDL, AP_Compass_LIS3MDL::probe(GET_I2C_DEVICE(i, HAL_COMPASS_LIS3MDL_I2C_ADDR), true, ROTATION_NONE));
-        ADD_BACKEND(DRIVER_LIS3MDL, AP_Compass_LIS3MDL::probe(GET_I2C_DEVICE(i, HAL_COMPASS_LIS3MDL_I2C_ADDR2), true, ROTATION_NONE));
-    }
-#elif CONFIG_HAL_BOARD == HAL_BOARD_LINUX && CONFIG_HAL_BOARD_SUBTYPE != HAL_BOARD_SUBTYPE_LINUX_NONE
-    ADD_BACKEND(DRIVER_HMC5843, AP_Compass_HMC5843::probe(GET_I2C_DEVICE(HAL_COMPASS_HMC5843_I2C_BUS, HAL_COMPASS_HMC5843_I2C_ADDR), ROTATION_NONE));
-    ADD_BACKEND(DRIVER_AK8963, AP_Compass_AK8963::probe_mpu9250(0, ROTATION_NONE));
-    ADD_BACKEND(DRIVER_LSM9DS1, AP_Compass_LSM9DS1::probe(hal.spi->get_device("lsm9ds1_m"), ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_BMM150_I2C
-    ADD_BACKEND(DRIVER_BMM150, AP_Compass_BMM150::probe(GET_I2C_DEVICE(HAL_COMPASS_BMM150_I2C_BUS, HAL_COMPASS_BMM150_I2C_ADDR), ROTATION_NONE));
-#elif HAL_COMPASS_DEFAULT == HAL_COMPASS_RM3100_SPI
-    ADD_BACKEND(DRIVER_RM3100, AP_Compass_RM3100::probe(hal.spi->get_device("rm3100"), ROTATION_NONE));
 #elif HAL_COMPASS_DEFAULT == HAL_COMPASS_NONE
-    // no compass
+    // no compass, or only external probe
 #else
     #error Unrecognised HAL_COMPASS_TYPE setting
 #endif