How do I manually cross-compile the Sterling supplicant from source?

It is best practice to include the source in your build system. If using Yocto, our external layer will do this for you.
Here is an example manually compiling using our SOM60 as a target in a Buildroot environment:

1. Download and extract the Sterling supplicant source.
2. Navigate to the "laird" directory.
3. Edit the config_laird file:
4. Find the following line, uncomment and change the path to your "openssl/include" directory:
   original line:
   #CFLAGS += -I/usr/local/openssl/include
   modified line:
   CFLAGS += -I/wb/buildroot/output/som60sd/build/host-libopenssl-1.1.1d/include
5. Run make with the following flags
   set:
CC="" for your cross-compile binary
PKG_CONFIG="" for your pkg-config binary
PKG_CONFIG_PATH="" for your pkgconfig directory
OBJCOPY="" for your objcopy binary

Note the following example is a single line command:
make CC="/wb/buildroot/output/som60sd/host/bin/arm-buildroot-linux-gnueabihf-gcc" PKG_CONFIG="/wb/buildroot/output/som60sd/host/bin/pkg-config" OBJCOPY="/wb/buildroot/output/som60sd/host/arm-buildroot-linux-gnueabihf/bin/objcopy" PKG_CONFIG_PATH="/wb/buildroot/output/som60sd/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/pkgconfig"