我安装了适用于 RPI2 的 Ubuntu Bionic 映像，并按照 Ubuntu 的说明添加了 Wi-Fi 驱动程序维基文档。但是，当我成功启动我的树莓派时，Ubuntu 无法检测到内置的 Wi-Fi 芯片组，但它可以检测到外部 USB Wi-Fi 适配器。我该怎么办？
ubuntu@ubuntu:~$ sudo lshw -C
network
*-network:0
description: Ethernet interface
physical id: 2
logical name: eth0
serial: b8:27:eb:e9:56:7d
size: 10Mbit/s
capacity: 100Mbit/s
capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=smsc95xx driverversion=22-Aug-2005 duplex=half firmware=smsc95xx USB 2.0 Ethernet link=no multicast=yes port=MII speed=10Mbit/s
*-network:1
description: Wireless interface
physical id: 3
bus info: usb@1:1.3
logical name: wlan0
serial: b4:fc:75:a0:0a:dd
capabilities: ethernet physical wireless
configuration: broadcast=yes driver=rt2800usb driverversion=4.15.0-1010-raspi2 firmware=0.36 ip=172.30.1.30 link=yes multicast=yes wireless=IEEE 802.11
ubuntu@ubuntu:~$ dmesg | grep -e
brcm -e sdio
[ 2.164893] brcmvirt-gpio
soc:virtgpio: Failed to set
gpiovirtbuf,
trying to get err:0
[ 21.403456] brcmfmac:
brcmf_fw_map_chip_to_name: using
brcm/brcmfmac43430-sdio.bin for chip
0x00a9a6(43430) rev 0x000001
[ 21.471550] usbcore: registered
new interface driver brcmfmac
[ 25.073769] brcmfmac mmc1:0001:1:
Direct firmware load for
brcm/brcmfmac43430-sdio.txt failed
with error -2
[ 26.100037] brcmfmac:
brcmf_sdio_htclk: HT Avail timeout
(1000000): clkctl 0x50
[ 27.135373] brcmfmac:
brcmf_sdio_htclk: HT Avail timeout
(1000000): clkctl 0x50