The package uses the nRFx SDK package `nrfx`. In addition, the `mynewt-nimble` repository contains some files (`porting/nimble/src/hal_timer.c` and `porting/npl/riot/src/nrf5x_isr.c`) that are compilable only for nRF MCUs. To allow the compilation for other platforms, the use of the `nrfx` package and the compilation of these files are now dependent on the use of any nRF5x MCU.