[[This is part 1 or several commits]]

We developed a huge Changeset over a year ago to make USB Composite configuration dynamical and be able to instanciate the CDCACM multiple times inside this device.  We use this feature to switch between one in normal and up to three CDCACMs in maintenance boot.

The control path starts in “boardctl.c” where the configuration for the device is constructed.  There are still a few issues which I’ll ask you to have a look at before this beast can be merged.

1. To be able to construct the data dynamically I have changed some USB-Structs to be packed. Maybe there are additional structs to change (just for completeness – not for current functionality).

2. I’ve added the Macro “COMPILE_TIME_ASSERTION” two times (in usbmsc_desc.c and in cdcacm_desc.c) to stay private. Maybe you’ll find a better place. It’s used to check the size of the structs against the assumptions.

3. I’ve changed the interface for some USB-Functions to receive also the dynamic configuration. Maybe this can be done more elegant.

4. The original NuttX (without the patch) seems to have problems with a Composite device holding a CDCACM and an MSC. The “USB SET CONFIGURATION” request does not to work at all. This makes the test fail under Windows and under Linux. Applying this patch doesn’t change anything – because it only changes the configuration – not the behavior. Maybe you’ll have a look at this problem before applying the patch.