Hi,
I just did a quick diff using these two commands
> find nRF5_SDK_12.0.0_12f24da/ -type f | grep --text -v -e "c$" -e "h$" -e "s$" | sed 's/.*\///' | sort -u > exclude_list
> diff nRF5_SDK_12.0.0_12f24da nRF5_SDK_12.1.0_0d23e2a -r --ignore-all-space -X exclude_list -x *dox_config.h > diff_SDK12.0_SDK12.1.patch
This will only give differences in *.s, .c and *.h files excluding *dox_config.h.
excluded *dox_config.h because it is basically doxygen corrections.