Raspberry Pi 4 as a wireless access point

Hello,

I've configured a Raspberry Pi 4 as a router with OpenBSD 7.2, with great performance.
The driver for the internal wireless NIC (bwfm) states that it can operate in AP mode.
I got the card configured correctly, but it doesn't broadcast the SSID.
I can't connect manually either.

Here's /etc/hostname.bwfm0:

gw$ cat /etc/hostname.bwfm0
mediaopt hostap
nwid (...) wpakey (...)
inet 10.0.12.1 255.255.255.0

And here's the output from ifconfig:
gw$ sudo ifconfig bwfm0
bwfm0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr dc:a6:32:8d:61:16
index 4 priority 4 llprio 3
groups: wlan
media: IEEE802.11 autoselect hostap (autoselect mode 11n hostap)
status: active
ieee80211: nwid (...) chan 2 bssid dc:a6:32:8d:61:16 wpakey wpaprotos wpa2 wpaakms psk wpaciphers ccmp wpagroupcipher ccmp
inet 10.0.12.1 netmask 0xffffff00 broadcast 10.0.12.255


Do I need to configure hostapd(8) as well?
If so, is there an example config out there for my situation?
I've looked at the sample, and it seems too complex for my needs.

Regards, Martin