有以下问题：
bsd# cat /var/log/messages | grep bwn
Nov 2 21:04:14 bsd kernel: siba_bwn0: mem 0xf69fc000-0xf69fffff irq 17 at device 0.0 on pci12
Nov 2 21:04:14 bsd kernel: bwn0 on siba_bwn0Nov 2 21:04:14 bsd kernel: bwn0: WLAN (chipid 0x4312 rev 15) PHY (analog 6 type 5 rev 1) RADIO (manuf 0x17f ver 0x2062 rev 2)
Nov 2 21:04:14 bsd kernel: bwn0: PIONov 2 21:04:14 bsd kernel: bwn0: Using 1 MSI messagesNov 2 21:04:14 bsd kernel: bwn0: [FILTER]
Nov 2 21:05:39 bsd kernel: bwn_v4_lp_ucode15: could not load firmware image, error 2
Nov 2 21:05:39 bsd kernel: bwn0: the fw file(bwn_v4_lp_ucode15) not found
Nov 2 21:05:39 bsd kernel: bwn-open_v4_lp_ucode15: could not load firmware image, error 2Nov 2 21:05:39 bsd kernel: bwn0: the fw file(bwn-open_v4_lp_ucode15) not found
Nov 2 21:09:37 bsd kernel: bwn_v4_lp_ucode15: could not load firmware image, error 2Nov 2 21:09:37 bsd kernel: bwn0: the fw file(bwn_v4_lp_ucode15) not found
Nov 2 21:09:37 bsd kernel: bwn-open_v4_lp_ucode15: could not load firmware image, error 2Nov 2 21:09:37 bsd kernel: bwn0: the fw file(bwn-open_v4_lp_ucode15) not found
The driver tells you it can't find the modules. Are the modules installed? If yes, load them with kldload(8). The modules are in /boot/modules, and the driver works without hw.bwn.usedma=0.找不到模块的原因
ports中net/bwn-firmware-kmod去安装（是用其它电脑和U盘复制过来的）
kldload bwn_v4_ucode.ko
kldload bwn_v4_lp_ucode.ko
或者：
if_bwn_load="YES"
bwn_v4_ucode_load="YES"
bwn_v4_lp_ucode_load="YES"