microbit: Introduced microbitDevice.[h,cpp] to hold platform specific low

level functionality

inc/MicroBitDevice.h

@@ -0,0 +1,24 @@
+/**
+ * Device specific funcitons for the nrf51822 device.
+ *
+ * Provides a degree of platform independence for microbit-dal functionality.
+ * TODO: Determine is any o this belongs in an mbed target definition.
+ * TODO: Review microbit-dal to place all such functions here.
+ *
+ */
+#ifndef MICROBIT_DEVICE_H
+#define MICROBIT_DEVICE_H
+/* 
+ * The underlying Nordic libraries that support BLE do not compile cleanly with the stringent GCC settings we employ
+ * If we're compiling under GCC, then we suppress any warnings generated from this code (but not the rest of the DAL)
+ * The ARM cc compiler is more tolerant. We don't test __GNUC__ here to detect GCC as ARMCC also typically sets this
+ * as a compatability option, but does not support the options used...
+ */
+
+/**
+  * Determines if a BLE stack is currnetly running.
+  * @return true is a bluetooth stack is operational, false otherwise.
+  */
+bool ble_running();
+
+#endif

source/MicroBitDevice.cpp

@@ -0,0 +1,53 @@
+/**
+  * Compatibility / portability funcitons and constants for the MicroBit DAL.
+  */
+#include "mbed.h"
+#include "ErrorNo.h"
+
+/**
+  * Turn off warnings under gcc -Wall. We turn off unused-function for the
+  * entire compilation unit as the compiler can't tell if a function is
+  * unused until the end of the unit.  The macro expansion for SVCALL()
+  * in nrf_soc.h and nrf_srv.h tries to leave unused-function turned off,
+  * but we restore the state from before the include with our diagnostics
+  * pop.
+  * It might be cleaner to add
+  * #pragram GCC system header
+  * as the first line of nrf_soc.h, but that's a different
+  * module ...
+  */
+
+
+/* 
+ * The underlying Nordic libraries that support BLE do not compile cleanly with the stringent GCC settings we employ
+ * If we're compiling under GCC, then we suppress any warnings generated from this code (but not the rest of the DAL)
+ * The ARM cc compiler is more tolerant. We don't test __GNUC__ here to detect GCC as ARMCC also typically sets this
+ * as a compatability option, but does not support the options used...
+ */
+#if !defined(__arm)
+#pragma GCC diagnostic ignored "-Wunused-function"
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#endif
+
+#include "nrf_soc.h"
+#include "nrf_sdm.h"
+
+/* 
+ * Return to our predefined compiler settings.
+ */
+#if !defined(__arm)
+#pragma GCC diagnostic pop
+#endif
+
+/**
+  * Determines if a BLE stack is currnetly running.
+  * @return true is a bluetooth stack is operational, false otherwise.
+  */
+bool ble_running()
+{
+    uint8_t t;
+    sd_softdevice_is_enabled(&t);
+    return t==1;
+}
+