Adding drivers to the pistachio snapshot?

I have a Creator Ci40 and can successfully install and upgrade pistachio development snapshot builds.
It would be really useful to be able to use IEEE 802.15.4 and WiFi but the drivers are not included in the snapshot builds. Sources for the two drivers are available from GitHub:

  1. Cascoda CA-8210 IEEE 802.15.4 transceiver

The snapshot builds do include a driver for the Texas Instruments CC2520 IEEE 802.15.4 transceiver (which may have been used on an earlier revision of the Creator Ci40).

Ideally, I would like to see these drivers included in the snapshot builds. Until then I would like to be able to build these drivers myself. I have been trying to understand the build process but haven't yet figured out how to obtain the default config used for the pistachio snapshot builds. Can anyone point me to a guide to adding drivers?

Using the cc2520 as a model I suspect that an entry for the ca8210 would have to be added to package/kernel/linux/modules/wpan.mk and a similar entry for the uccp420wlan would have to be added to package/kernel/linux/modules/wireless.mk? After that I'm not sure ...

Is anyone else trying anything similar for the Creator Ci40?