CONFIG_KEXEC_FILE is not available for thedefaultarchitecture x86.
Result is shown for architecture s390

kexec file based system call

modulename: machine_kexec_file.ko

and/or

kexec_elf.ko

and/or

elf_kexec.ko

and/or

kexec-bzimage64.ko

and/or

file_load.ko

and/or

kexec_file.ko

configname: CONFIG_KEXEC_FILE

Linux Kernel Configuration
└─>Processor type and features
└─>kexec file based system call
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Enable the kexec file based system call. In contrast to the normal
kexec system call this system call takes file descriptors for the
kernel and initramfs as arguments.

source code: