Add requiresUSBMavlinkStart support

src/comm/LinkInterface.h

@@ -125,6 +125,9 @@ public:
     /// set into the link when it is added to LinkManager
     uint8_t getMavlinkChannel(void) const { Q_ASSERT(_mavlinkChannelSet); return _mavlinkChannel; }
 
+    /// @return true: "sh /etc/init.d/rc.usb" must be sent on link to start mavlink
+    virtual bool requiresUSBMavlinkStart(void) const { return false; }
+
     // These are left unimplemented in order to cause linker errors which indicate incorrect usage of
     // connect/disconnect on link directly. All connect/disconnect calls should be made through LinkManager.
     bool connect(void);

src/comm/MAVLinkProtocol.cc

@@ -200,14 +200,16 @@ void MAVLinkProtocol::_linkStatusChanged(LinkInterface* link, bool connected)
         // Use the same shared pointer as LinkManager
         _connectedLinks.append(_linkMgr->sharedPointerForLink(link));
         
-        // Send command to start MAVLink
-        // XXX hacky but safe
-        // Start NSH
-        const char init[] = {0x0d, 0x0d, 0x0d, 0x0d};
-        link->writeBytes(init, sizeof(init));
-        const char* cmd = "sh /etc/init.d/rc.usb\n";
-        link->writeBytes(cmd, strlen(cmd));
-        link->writeBytes(init, 4);
+        if (link->requiresUSBMavlinkStart()) {
+            // Send command to start MAVLink
+            // XXX hacky but safe
+            // Start NSH
+            const char init[] = {0x0d, 0x0d, 0x0d, 0x0d};
+            link->writeBytes(init, sizeof(init));
+            const char* cmd = "sh /etc/init.d/rc.usb\n";
+            link->writeBytes(cmd, strlen(cmd));
+            link->writeBytes(init, 4);
+        }
     } else {
         bool found = false;
         for (int i=0; i<_connectedLinks.count(); i++) {

src/comm/SerialLink.cc

@@ -15,10 +15,8 @@
 
 #ifdef __android__
 #include "qserialport.h"
-#include "qserialportinfo.h"
 #else
 #include <QSerialPort>
-#include <QSerialPortInfo>
 #endif
 
 #include "SerialLink.h"
@@ -26,6 +24,7 @@
 #include "MG.h"
 #include "QGCLoggingCategory.h"
 #include "QGCApplication.h"
+#include "QGCSerialPortInfo.h"
 
 QGC_LOGGING_CATEGORY(SerialLinkLog, "SerialLinkLog")
 
@@ -380,6 +379,15 @@ LinkConfiguration* SerialLink::getLinkConfiguration()
     return _config;
 }
 
+bool SerialLink::requiresUSBMavlinkStart(void) const
+{
+    if (_port) {
+        return QGCSerialPortInfo(*_port).boardTypePixhawk();
+    } else {
+        return false;
+    }
+}
+
 //--------------------------------------------------------------------------
 //-- SerialConfiguration
 

src/comm/SerialLink.h

@@ -119,7 +119,8 @@ public:
     void    requestReset();
     bool    isConnected() const;
     qint64  getConnectionSpeed() const;
-    
+    bool    requiresUSBMavlinkStart(void) const;
+
     // These are left unimplemented in order to cause linker errors which indicate incorrect usage of
     // connect/disconnect on link directly. All connect/disconnect calls should be made through LinkManager.
     bool    connect(void);