Hi, I would like to reserve some registers in ARM64 processor and prohibit the compiler from using them in any scenario. For example: ARM64 Thirty-one 64-bit general-purpose registers X0-X30. I want to reserve register X30, and make sure when I compile any code using gcc, it won't use register X30 in any situation. How can this be done? Any help would be greatly appreciated. Thanks, Nisal