[fedora-arm] activation of SPI on fedora26 with a raspberry3

Hello, I try to activate the spi on my raspberry3 using a fedora 26. I tried these options: device_tree_param=spi=on dtoverlay=spi-bcm2708 I use this kernel: 4.12.5-300.fc26.armv7hl I see that the support in kernel seems already inside: CONFIG_SPI=y # CONFIG_SPI_DEBUG is not set CONFIG_SPI_MASTER=y But I never see the devices /dev/spi* appearing. I can't see any messages regarding spi in dmesg. I tested with a raspbian and I see them correctly. I think I miss somethiing. Could you help. Thanks.