According the talk[1], because the architecture get updated, what used to be a RES1 bit becomes a functinal bit. So we can define the name for these bits, this also increase the readability. [1] lore.kernel.org/ZLZQ6r4-9mVdg4Ry@monolith.localdoman Shaoqin Huang (2): arm64: Replace the SCTLR_EL1 filed definition by _BITUL() arm64: Define name for the bits used in SCTLR_EL1_RES1 lib/arm64/asm/sysreg.h | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-) -- 2.39.1