Vanilla kernels with custom configs

Typical content of a kernel-${KVER}-${KTYPE}.tar tarball:

boot/System.map-${KVER}-${KTYPE}
boot/config-${KVER}-${KTYPE}
boot/vmlinuz-${KVER}-${KTYPE}
boot/initrd-${KVER}-${KTYPE}
boot/initramfs-${KVER}-${KTYPE}.img
lib/modules/${KVER}-${KTYPE}/*