DS1820 not Works

[delta117]

I've intalled piCore 8 but there in no /sys/bus/w1 and so on

My config.txt with 

dtoverlay=w1-gpio,gpiopin=4,pullup=on

the reboot lsmod show nothing related with w1-
so i tried sudo modprobe w1-gpio and sudo modprobe w1-therm
then I get follow error

modprobe: module w1-gpio not found in modules.dep
modprobe: module w1-therm not found in modules.dep

Is there a way to solve the problem

Dietmar