Hello, I'm trying to apply the described procedure to OrangePrime. Unfortunatly it tries to download kernel packages. I've tried the patch with no luck. Afterwards, I've downloaded a kernel and matching RT patch, put in /build directory and edited /config/lib/configuration.sh to change REVISION="5.45XX" to "5.41", to match downloaded kernel (4.14.18).
Selected PREEMPT_RT_FULL and got:
kernel/softirq.c:806:2: error: #else without #if
#else /* PREEMPT_RT_FULL */
kernel/softirq.c:807:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statem