ESR_IDFSC_MASK 87 kernel/arch/arm64/src/exception.c switch ((esr_el1 & ESR_IDFSC_MASK) >> ESR_IDFSC_SHIFT) { ESR_IDFSC_MASK 157 kernel/arch/arm64/src/exception.c switch ((esr_el1 & ESR_IDFSC_MASK) >> ESR_IDFSC_SHIFT) {HelenOS homepage, sources at GitHub