Can't use wifi

Help Section
1

I cannot use wifi anymore,I can use it with no problem before.I open wifi networkmanager,after enter password I get an error message:
No wifi interface is configured in /etc/rc.conf.

2

Hi @unicorn,

could you please provide the output of the following commands?:

% sysctl net.wlan.devices
% service -e
% grep ifconfig /etc/rc.conf
3

sysctl net.wlan.devices and grep ifconfig /etc/rc.conf output nothing.
service -e output:
/etc/rc.d/hostid
/etc/rc.d/hostid_save
/etc/rc.d/cleanvar
/etc/rc.d/kldxref
/etc/rc.d/ip6addrctl
/etc/rc.d/netif
/etc/rc.d/devd
/etc/rc.d/resolv
/etc/rc.d/newsyslog
/etc/rc.d/syslogd
/etc/rc.d/savecore
/etc/rc.d/dmesg
/etc/rc.d/virecover
/etc/rc.d/motd
/etc/rc.d/rctl
/etc/rc.d/sendmail
/etc/rc.d/mixer
/etc/rc.d/cron
/etc/rc.d/gptboot
/etc/rc.d/devmatch
/etc/rc.d/bgfsck

4

my system start with command prompt
login:[drmxxxxfifo_underrun_xxxxxxx]xxxxx fifo underrun on pipe A
[drm:intel_cpu_fifo_underrun_xxxx_xxxxx_xxxxx]cpu pipe A fifo underrun

I enter my username and password after hit enter,and then type startx and desktop appear

5

It seems the content of /etc/rc.conf got lost. You can fix that as follows:

sudo cp /usr/share/nomadbsd-setup/rc.conf.in /etc/rc.conf

Then reboot.