GCC Strikes again
GCC strikes again, generating unaligned memory access on ARM processors, causing them to trap:
https://github.com/babbleberry/rpi4-osdev/issues/17
When using GCC for an aarch64 target you need the option -mstrict-align to prevent GCC from producing incompatible instructions.
For aarch32 targets you need -mno-unaligned-access.