HAL_PX4: support flashing bootloader with MAVLink command

libraries/AP_HAL_PX4/Util.cpp

@@ -14,6 +14,7 @@
 #include <systemlib/board_serial.h>
 #include <drivers/drv_gpio.h>
 #include <AP_Math/AP_Math.h>
+#include <AP_BoardConfig/AP_BoardConfig.h>
 
 extern const AP_HAL::HAL& hal;
 
@@ -261,4 +262,18 @@ void PX4Util::free_type(void *ptr, size_t size, AP_HAL::Util::Memory_Type mem_ty
 #endif
 }
 
+extern "C" {
+    int bl_update_main(int argc, char *argv[]);
+};
+
+bool PX4Util::flash_bootloader()
+{
+    if (AP_BoardConfig::px4_start_driver(bl_update_main, "bl_update", "/etc/bootloader/fmu_bl.bin")) {
+        hal.console->printf("updated bootloader\n");
+        return true;
+    }
+    return false;
+}
+
+
 #endif // CONFIG_HAL_BOARD == HAL_BOARD_PX4

libraries/AP_HAL_PX4/Util.h

@@ -60,6 +60,8 @@ public:
     void *malloc_type(size_t size, AP_HAL::Util::Memory_Type mem_type) override;
     void free_type(void *ptr, size_t size, AP_HAL::Util::Memory_Type mem_type) override;
 
+    bool flash_bootloader() override;
+    
 private:
     int _safety_handle;
     PX4::NSHShellStream _shell_stream;