HelenOS sources

ESR_EC_DA_LOWER_EL  129 boot/arch/arm64/include/arch/regutils.h #define ESR_EC_DA_LOWER_EL  0x24
ESR_EC_DA_LOWER_EL  129 kernel/arch/arm64/include/arch/regutils.h #define ESR_EC_DA_LOWER_EL  0x24
ESR_EC_DA_LOWER_EL  129 uspace/lib/c/arch/arm64/include/libarch/regutils.h #define ESR_EC_DA_LOWER_EL  0x24

HelenOS homepage, sources at GitHub