ID_PFR1_GEN_TIMER_EXT_MASK 52 kernel/arch/arm32/include/arch/cycle.h if ((ID_PFR1_read() & ID_PFR1_GEN_TIMER_EXT_MASK) == ID_PFR1_GEN_TIMER_EXT_MASK 194 kernel/arch/arm32/src/cpu/cpu.c if ((ID_PFR1_read() & ID_PFR1_GEN_TIMER_EXT_MASK) !=HelenOS homepage, sources at GitHub