creating ios native extension with 3rd party frameworks

Hello,

I'm new to Air development and creating a ios native extension for my flex mobile project.I want to include third party frameworks such as admob,facebook,chartboost in my ANE

I have tried to link frameworks using packagedDependencies but it dosn't work.(gives me an error telling that "armv7 not supported")

am I doing something wrong? or is there any proper way to link frameworks?

platformoptions.xml

<platform xmlns="http://ns.adobe.com/air/extension/4.0">

     <sdkVersion>7.1</sdkVersion>

     <linkerOptions>

          <option>-ios_version_min 6.1</option>

          <option>-framework StoreKit</option>

          <option>-framework CoreGraphics</option>

          <option>-framework UIKit</option>

          <option>-framework Foundation</option>

     </linkerOptions>

     <packagedDependencies>

         <packagedDependency>frameworks/Chartboost.framework</packagedDependency>

         <packagedDependency>ios/libAdExtension.a</packagedDependency>

    </packagedDependencies>

</platform>

extensionxml

<extension xmlns="http://ns.adobe.com/air/extension/4.0">

    <id>com.my.extensions</id>

    <versionNumber>1</versionNumber>

        <platforms>

            <platform name="iPhone-ARM">

            <applicationDeployment>

            <nativeLibrary>libAdExtension.a</nativeLibrary>

            <initializer>ExtInitializer</initializer>

            <finalizer>ExtFinalizer</finalizer>

            </applicationDeployment>

        </platform>

    </platforms>

</extension>

-command

/Applications/Adobe\ Flash\ Builder\ 4.7/sdks/4.6.0+airSDK4.0/bin/adt -package -target ane adExtension.ane extension.xml -swc bin/AdsLibrary.swc -platform iPhone-ARM library.swf frameworks/Chartboost.framework ios/libAdExtension.a -C ios . -platformoptions platformoptions.xml

-error

ld: warning: ignoring file /var/folders/3r/x0bh_4.... file was built for unsupported file format ( 0Undefined symbols for architecture armv7:

  "_OBJC_CLASS_$_Chartboost", referenced from:

ld: symbol(s) not found for architecture armv7

Compilation failed while executing : ld64

*I used lipo to combine simulator and device .a files

please help