diff --git a/libraries/AP_Compass/AP_Compass_AK8963.cpp b/libraries/AP_Compass/AP_Compass_AK8963.cpp
index 567c0d294e..0ab59ef829 100644
--- a/libraries/AP_Compass/AP_Compass_AK8963.cpp
+++ b/libraries/AP_Compass/AP_Compass_AK8963.cpp
@@ -228,10 +228,10 @@ void AP_Compass_AK8963::_update()
     float mag_x, mag_y, mag_z;
     // get raw_field - sensor frame, uncorrected
     Vector3f raw_field;
-    uint32_t time_us = hal.scheduler->micros();
+    uint32_t time_us = AP_HAL::micros();
 
 
-    if (hal.scheduler->micros() - _last_update_timestamp < 10000) {
+    if (AP_HAL::micros() - _last_update_timestamp < 10000) {
         goto end;
     }
 
@@ -284,7 +284,7 @@ void AP_Compass_AK8963::_update()
         _accum_count = 5;
     }
 
-    _last_update_timestamp = hal.scheduler->micros();
+    _last_update_timestamp = AP_HAL::micros();
 fail:
     _sem_give();
 end:
@@ -356,7 +356,7 @@ bool AP_Compass_AK8963::_sem_take_nonblocking()
     if (!hal.scheduler->system_initializing() ) {
         _sem_failure_count++;
         if (_sem_failure_count > 100) {
-            hal.scheduler->panic("PANIC: failed to take _bus->sem "
+            AP_HAL::panic("PANIC: failed to take _bus->sem "
                                  "100 times in a row, in "
                                  "AP_Compass_AK8963");
         }
@@ -393,7 +393,7 @@ AP_AK8963_SerialBus_MPU9250::AP_AK8963_SerialBus_MPU9250(AP_InertialSensor &ins,
     // getting the semaphore
     _bus = ins.get_auxiliary_bus(HAL_INS_MPU9250, mpu9250_instance);
     if (!_bus)
-        hal.scheduler->panic("Cannot get MPU9250 auxiliary bus");
+        AP_HAL::panic("Cannot get MPU9250 auxiliary bus");
 
     _slave = _bus->request_next_slave(addr);
 }
diff --git a/libraries/AP_Compass/AP_Compass_Backend.cpp b/libraries/AP_Compass/AP_Compass_Backend.cpp
index 4fc29279d5..1e937c45a1 100644
--- a/libraries/AP_Compass/AP_Compass_Backend.cpp
+++ b/libraries/AP_Compass/AP_Compass_Backend.cpp
@@ -43,7 +43,7 @@ void AP_Compass_Backend::publish_raw_field(const Vector3f &mag, uint32_t time_us
 {
     Compass::mag_state &state = _compass._state[instance];
 
-    state.last_update_ms = hal.scheduler->millis();
+    state.last_update_ms = AP_HAL::millis();
 
     // note that we do not set last_update_usec here as otherwise the
     // EKF and DCM would end up consuming compass data at the full
@@ -110,8 +110,8 @@ void AP_Compass_Backend::publish_filtered_field(const Vector3f &mag, uint8_t ins
 
     state.field = mag;
 
-    state.last_update_ms = hal.scheduler->millis();
-    state.last_update_usec = hal.scheduler->micros();
+    state.last_update_ms = AP_HAL::millis();
+    state.last_update_usec = AP_HAL::micros();
 
     state.has_raw_field = state.updated_raw_field;
     state.updated_raw_field = false;
diff --git a/libraries/AP_Compass/AP_Compass_HIL.cpp b/libraries/AP_Compass/AP_Compass_HIL.cpp
index 671fcf2b56..3b76ba2ea7 100644
--- a/libraries/AP_Compass/AP_Compass_HIL.cpp
+++ b/libraries/AP_Compass/AP_Compass_HIL.cpp
@@ -64,7 +64,7 @@ void AP_Compass_HIL::read()
             uint8_t compass_instance = _compass_instance[i];
             Vector3f field = _compass._hil.field[compass_instance];
             rotate_field(field, compass_instance);
-            publish_raw_field(field, hal.scheduler->micros(), compass_instance);
+            publish_raw_field(field, AP_HAL::micros(), compass_instance);
             correct_field(field, compass_instance);
             publish_filtered_field(field, compass_instance);
         }
diff --git a/libraries/AP_Compass/AP_Compass_HMC5843.cpp b/libraries/AP_Compass/AP_Compass_HMC5843.cpp
index 19f8dc4260..4ec375fe07 100644
--- a/libraries/AP_Compass/AP_Compass_HMC5843.cpp
+++ b/libraries/AP_Compass/AP_Compass_HMC5843.cpp
@@ -119,7 +119,7 @@ AP_Compass_Backend *AP_Compass_HMC5843::_detect(Compass &compass,
 bool AP_Compass_HMC5843::read_register(uint8_t address, uint8_t *value)
 {
     if (_bus->register_read(address, value) != 0) {
-        _retry_time = hal.scheduler->millis() + 1000;
+        _retry_time = AP_HAL::millis() + 1000;
         return false;
     }
     return true;
@@ -129,7 +129,7 @@ bool AP_Compass_HMC5843::read_register(uint8_t address, uint8_t *value)
 bool AP_Compass_HMC5843::write_register(uint8_t address, uint8_t value)
 {
     if (_bus->register_write(address, value) != 0) {
-        _retry_time = hal.scheduler->millis() + 1000;
+        _retry_time = AP_HAL::millis() + 1000;
         return false;
     }
     return true;
@@ -142,7 +142,7 @@ bool AP_Compass_HMC5843::read_raw()
 
     if (_bus->read_raw(&rv) != 0) {
         _bus->set_high_speed(false);
-        _retry_time = hal.scheduler->millis() + 1000;
+        _retry_time = AP_HAL::millis() + 1000;
         return false;
     }
 
@@ -178,7 +178,7 @@ void AP_Compass_HMC5843::accumulate(void)
         return;
     }
 
-   uint32_t tnow = hal.scheduler->micros();
+   uint32_t tnow = AP_HAL::micros();
    if (_accum_count != 0 && (tnow - _last_accum_time) < 13333) {
 	  // the compass gets new data at 75Hz
 	  return;
@@ -439,11 +439,11 @@ void AP_Compass_HMC5843::read()
         return;
     }
     if (_retry_time != 0) {
-        if (hal.scheduler->millis() < _retry_time) {
+        if (AP_HAL::millis() < _retry_time) {
             return;
         }
         if (!re_initialise()) {
-            _retry_time = hal.scheduler->millis() + 1000;
+            _retry_time = AP_HAL::millis() + 1000;
             _bus->set_high_speed(false);
             return;
         }
diff --git a/libraries/AP_Compass/AP_Compass_LSM303D.cpp b/libraries/AP_Compass/AP_Compass_LSM303D.cpp
index 3e52709ce7..681bbea134 100644
--- a/libraries/AP_Compass/AP_Compass_LSM303D.cpp
+++ b/libraries/AP_Compass/AP_Compass_LSM303D.cpp
@@ -302,7 +302,7 @@ AP_Compass_LSM303D::init()
     uint8_t whoami = _register_read(ADDR_WHO_AM_I);
     if (whoami != WHO_I_AM) {
         hal.console->printf("LSM303D: unexpected WHOAMI 0x%x\n", (unsigned)whoami);
-        hal.scheduler->panic("LSM303D: bad WHOAMI");
+        AP_HAL::panic("LSM303D: bad WHOAMI");
     }
 
     uint8_t tries = 0;
@@ -312,7 +312,7 @@ AP_Compass_LSM303D::init()
         if (success) {
             hal.scheduler->delay(5+2);
             if (!_spi_sem->take(100)) {
-                hal.scheduler->panic("LSM303D: Unable to get semaphore");
+                AP_HAL::panic("LSM303D: Unable to get semaphore");
             }
             if (_data_ready()) {
                 _spi_sem->give();
@@ -324,7 +324,7 @@ AP_Compass_LSM303D::init()
             _spi_sem->give();
         }
         if (tries++ > 5) {
-            hal.scheduler->panic("PANIC: failed to boot LSM303D 5 times");
+            AP_HAL::panic("PANIC: failed to boot LSM303D 5 times");
         }
     } while (1);
 
@@ -356,7 +356,7 @@ uint32_t AP_Compass_LSM303D::get_dev_id()
 bool AP_Compass_LSM303D::_hardware_init(void)
 {
     if (!_spi_sem->take(100)) {
-        hal.scheduler->panic("LSM303D: Unable to get semaphore");
+        AP_HAL::panic("LSM303D: Unable to get semaphore");
     }
 
     // initially run the bus at low speed
@@ -385,7 +385,7 @@ bool AP_Compass_LSM303D::_hardware_init(void)
 
 void AP_Compass_LSM303D::_update()
 {
-    if (hal.scheduler->micros() - _last_update_timestamp < 10000) {
+    if (AP_HAL::micros() - _last_update_timestamp < 10000) {
         return;
     }
 
@@ -395,7 +395,7 @@ void AP_Compass_LSM303D::_update()
 
     _collect_samples();
 
-    _last_update_timestamp = hal.scheduler->micros();
+    _last_update_timestamp = AP_HAL::micros();
     _spi_sem->give();
 }
 
@@ -409,7 +409,7 @@ void AP_Compass_LSM303D::_collect_samples()
         error("_read_raw() failed\n");
     } else {
         Vector3f raw_field = Vector3f(_mag_x, _mag_y, _mag_z) * _mag_range_scale;
-        uint32_t time_us = hal.scheduler->micros();
+        uint32_t time_us = AP_HAL::micros();
 
         // rotate raw_field from sensor frame to body frame
         rotate_field(raw_field, _compass_instance);
diff --git a/libraries/AP_Compass/Compass.cpp b/libraries/AP_Compass/Compass.cpp
index f9ab928829..30181a221f 100644
--- a/libraries/AP_Compass/Compass.cpp
+++ b/libraries/AP_Compass/Compass.cpp
@@ -400,7 +400,7 @@ Compass::init()
 uint8_t Compass::register_compass(void)
 {
     if (_compass_count == COMPASS_MAX_INSTANCES) {
-        hal.scheduler->panic("Too many compass instances");
+        AP_HAL::panic("Too many compass instances");
     }
     return _compass_count++;
 }
@@ -410,7 +410,7 @@ void Compass::_add_backend(AP_Compass_Backend *backend)
     if (!backend)
         return;
     if (_backend_count == COMPASS_MAX_BACKEND)
-        hal.scheduler->panic("Too many compass backends");
+        AP_HAL::panic("Too many compass backends");
     _backends[_backend_count++] = backend;
 }
 
@@ -476,7 +476,7 @@ Compass::read(void)
         _backends[i]->read();
     }    
     for (uint8_t i=0; i < COMPASS_MAX_INSTANCES; i++) {
-        _state[i].healthy = (hal.scheduler->millis() - _state[i].last_update_ms < 500);
+        _state[i].healthy = (AP_HAL::millis() - _state[i].last_update_ms < 500);
     }
     return healthy();
 }
@@ -724,7 +724,7 @@ void Compass::setHIL(uint8_t instance, const Vector3f &mag)
 {
     _hil.field[instance] = mag;
     _hil.healthy[instance] = true;
-    _state[instance].last_update_usec = hal.scheduler->micros();
+    _state[instance].last_update_usec = AP_HAL::micros();
 }
 
 const Vector3f& Compass::getHIL(uint8_t instance) const