recently I tried getting cpuminer to run on a Raspberry Pi 4 (aarch64)
I'm using somewhat older codes (version 2.4) from
https://github.com/pooler/cpuminerI couldn't figure out how to get it to build with the ARM assembly codes, and apparently scrypt-arm.S seemed to be written for armhf (32 bit ARM microprocessors).
Hence, there could possibly with issues compiling in aarch64 (ARM 64bit instructions and OS)
It's not about issues, it's just plain incompatible. Despite the name similarity, 64-bit ARM (AArch64) is an entirely different architecture than 32-bit ARM, and the hand-written assembly code in cpuminer only targets the latter. I never got around to writing optimized code for AArch64, so all you can do at the moment is compile a C-only version of the miner.