Connect ME-9210 and DM-Crypt

Hi!

I’m trying to get dm-crypt running on my Digi Connect ME-9210 with the supplied Digi Embedded Linux 5.2

I build my own kernel with the needed crypt modules.
Now i’m trying to build cryptsetup but it wants popt.

./configure --host=arm-linux --build=i386-linux --prefix=/usr/local/DigiEL-5.2/usr

configure: error: You need popt 1.7 or newer to compile

When building popt 1.16 wchar.h ist missing.

popthelp.c:20:41: error: wchar.h: No such file or directory

How can I enable wchar.h in the provided uclibc?

Is there another way i should use to get encryption on my device?

Thanks in advance!