kexec is a system call that enables you to load and boot into another kernel from the currently running kernel
To load the new kernel # kexec -l path/to/kernel --initrd=path/to/initrd --command-line=arguments
To load a new kernel with current boot parameters # kexec -l path/to/kernel --initrd=path/to/initrd --reuse-cmdline
To execute a currently loaded kernel # kexec -e
To unload current kexec target kernel # kexec -u
regards, T.Dhanasekar