HelenOS sources

CCSELR_LEVEL_MASK  222 kernel/arch/arm32/src/cpu/cpu.c 	CSSELR_write((level & CCSELR_LEVEL_MASK) << CCSELR_LEVEL_SHIFT);
CCSELR_LEVEL_MASK  234 kernel/arch/arm32/src/cpu/cpu.c 	CSSELR_write((level & CCSELR_LEVEL_MASK) << CCSELR_LEVEL_SHIFT);
CCSELR_LEVEL_MASK  245 kernel/arch/arm32/src/cpu/cpu.c 	CSSELR_write((level & CCSELR_LEVEL_MASK) << CCSELR_LEVEL_SHIFT);
HelenOS homepage, sources at GitHub