Where can i get a list of all these family of ARM processors and their differences
Ah yes ARM64, and thereon hangs a tale. Linus Torvalds had a rant, and quite rightly too I think, about Aarch64 which is the name ARM gave to the 64 bit instruction set and ARMv8-A its name for the architecture
LKML: Linus Torvalds: Re: [PATCH 00/36] AArch64 Linux kernel port
So you'll get ARCH=arm64 when talking about operating systems, aarch64 when talking about a compiler. and references to armv8 when distinguishing between armv7 and armv8 features like cryptography.