If your application has been set to use softfp, then some libraries may export softfp variant of libraries that are not compatible with the default IAR Embedded Workbench hardfp mode. You must enable softfp VFP mode as follows:

  1. Open the Options dialog for you project/application.

  2. Go to

    C/C++ Compiler > Extra Options

    , and enable

    Use command line options

    .

  3. Enter the following in the entry box, and click

    OK

    :

    --aapcs std


For more information, refer to

https://wwwfiles.iar.com/arm/webic/doc/EWARM_DevelopmentGuide.ENU.pdf

.