kexec

TLDR

Load a new kernel

$ kexec -l [path/to/kernel] --initrd=[path/to/initrd] --command-line=[arguments]

Load a new kernel with current boot parameters

$ kexec -l [path/to/kernel] --initrd=[path/to/initrd] --reuse-cmdline

Execute a currently loaded kernel

$ kexec -e

Unload current kexec target kernel

$ kexec -u