上一篇我们安装好了CentOS 7系统，但是却发现笔记本电脑无法连接Wi-Fi，这是因为我的笔记本电脑使用博通的无线网卡，驱动不支持导致的。
本文主要从英文翻译过来，希望能帮助一些童鞋解决这个问题，如果英文差不多可以直接看CentOS论坛上这篇，可以完美解决。
前言
CentOS 7本身可以支持很多常见的无线网卡，但如果你不幸使用了博通公司的BCM4311, BCM4312, BCM4313, BCM4321, BCM4322, BCM43224, BCM43225, BCM43227 and BCM43228这些型号的无线网卡，就需要进行一些配置了。
注：本文所记录的方法主要针对EL6 and EL7
目录
- 步骤一：确定无线网卡型号，并安装依赖包
- 步骤二：下载、解压博通无线网卡驱动压缩包
- 步骤三：编译博通芯片驱动模块
- 步骤四：将驱动载入内核
- 步骤五：将驱动载入程序加入开机启动
步骤一：确定无线网卡型号，并安装依赖包
[user@host ~]$ /sbin/lspci | grep Broadcom
0b:00.0 Network controller: Broadcom Corporation BCM4312 802.11a/b/g (rev 01)
注：博主自己电脑网卡的型号是BCM43142，虽然原帖中没有列出来，也是没有关系的，方法完全适用
另外确定你在之后编译阶段没有缺失必要的宏包
[root@host ~]# yum install kernel-headers kernel-devel gcc
当然啦，如果你用的是服务器，要编译Xen kernel (i.e. kernel-xen)，那你需要下载kernel-xen-devel 而不是kernel-devel。
步骤二：下载、解压博通无线网卡驱动压缩包
从博通官网下载BCM43xx linux驱动包，并且解压到/usr/local/src/hybrid-wl
列了这么多，其实只需要根据情况下载第一个或者第二个就可以了。
[root@host ~]# mkdir -p /usr/local/src/hybrid-wl
[root@host hybrid-wl]# cd /usr/local/src/hybrid-wl
[root@host hybrid-wl]# tar xvfz /path/to/the/tarball/hybrid-v35_64-nodebug-pcoem-6_30_223_271.tar.gz
[root@host hybrid-wl]# chown -R someuser.somegroup /usr/local/src/hybrid-wl
步骤三：编译博通芯片驱动模块
[user@host hybrid-wl]$ make -C /lib/modules/`uname -r`/build/ M=`pwd`
根据目前这个版本的驱动，几乎可以肯定所有人都会编译出错，在CentOS 6上你会看到如下的情况：
make: Entering directory `/usr/src/kernels/2.6.32-573.7.1.el6.x86_64'
CFG80211 API is prefered for this kernel version
Using CFG80211 API
LD /usr/local/src/hybrid-wl/built-in.o
CC [M] /usr/local/src/hybrid-wl/src/shared/linux_osl.o
CC [M] /usr/local/src/hybrid-wl/src/wl/sys/wl_linux.o
CC [M] /usr/local/src/hybrid-wl/src/wl/sys/wl_iw.o
CC [M] /usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.o
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:83: warning: ‘enum tx_power_setting’ declared inside parameter list
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:83: warning: its scope is only this definition or declaration,
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c: In function ‘wl_cfg80211_join_ibss’:
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:730: error: ‘struct cfg80211_ibss_params’ has no member named ‘channel’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c: At top level:
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1096: warning: ‘enum tx_power_setting’ declared inside parameter list
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1096: error: parameter 2 (‘type’) has incomplete type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c: In function ‘wl_cfg80211_set_tx_power’:
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1107: error: ‘TX_POWER_AUTOMATIC’ undeclared (first use in this
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1107: error: (Each undeclared identifier is reported only once
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1107: error: for each function it appears in.)
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1109: error: ‘TX_POWER_LIMITED’ undeclared (first use in this function)
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1115: error: ‘TX_POWER_FIXED’ undeclared (first use in this function)
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c: At top level:
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1774: warning: initialization from incompatible pointer type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1779: warning: initialization from incompatible pointer type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1780: warning: initialization from incompatible pointer type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1781: warning: initialization from incompatible pointer type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1782: warning: initialization from incompatible pointer type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1783: warning: initialization from incompatible pointer type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1784: warning: initialization from incompatible pointer type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1789: warning: initialization from incompatible pointer type
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c: In function ‘wl_inform_single_bss’:/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1984: error: too few arguments to function
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2023: warning: passing argument 1 of ‘cfg80211_put_bss’ from include/net/cfg80211.h:3380: note: expected ‘struct wiphy *’ but argument is of type ‘struct cfg80211_bss *’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2023: error: too few arguments to function ‘cfg80211_put_bss’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c: In function ‘wl_update_bss_info’:
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2276: error: ‘struct cfg80211_bss’ has no member named
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2277: error: ‘struct cfg80211_bss’ has no member named
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2283: warning: passing argument 1 of ‘cfg80211_put_bss’ from include/net/cfg80211.h:3380: note: expected ‘struct wiphy *’ but argument is of type ‘struct cfg80211_bss *’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2283: error: too few arguments to function ‘cfg80211_put_bss’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c: In function ‘wl_bss_roaming_done’:
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2322: warning: passing argument 2 of ‘cfg80211_roamed’ from include/net/cfg80211.h:3726: note: expected ‘struct ieee80211_channel *’ but argument is of type ‘u8 *’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2322: warning: passing argument 4 of ‘cfg80211_roamed’ makes include/net/cfg80211.h:3726: note: expected ‘const u8 *’ but argument is of type ‘s32’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2322: warning: passing argument 5 of ‘cfg80211_roamed’ makes include/net/cfg80211.h:3726: note: expected ‘size_t’ but argument is of type ‘u8 *’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2322: warning: passing argument 6 of ‘cfg80211_roamed’ makes include/net/cfg80211.h:3726: note: expected ‘const u8 *’ but argument is of type ‘s32’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2322: error: too few arguments to function ‘cfg80211_roamed’
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c: In function ‘wl_update_wowl’:
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:2791: warning: unused variable ‘wdev’
make[1]: *** [/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.o] Error 1
make: *** [_module_/usr/local/src/hybrid-wl] Error 2
make: Leaving directory `/usr/src/kernels/2.6.32-573.7.1.el6.x86_64'
注：博主发现在el7上错误信息和上面列的相同
接下来就是el6和el7步骤不同的地方
EL6
在EL6上，因为内核中if-then-else语句会搜寻wl_cfg80211_hybrid.c这个文件，为了修正这个问题，我们运行以下语句：
[user@host hybrid-wl]$ sed -i 's/[ >][>=] KERNEL_VERSION(2, 6, 3.)/>= KERNEL_VERSION(2, 6, 32)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/[ >][>=] KERNEL_VERSION(3, ., .)/>= KERNEL_VERSION(2, 6, 32)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/[ >][>=] KERNEL_VERSION(3, 11, .)/>= KERNEL_VERSION(2, 6, 32)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/< KERNEL_VERSION(3, 18, .)/< KERNEL_VERSION(2, 6, 30)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/[ >][>=] KERNEL_VERSION(3, 15, .)/>= KERNEL_VERSION(2, 6, 32)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/[ >][>=] KERNEL_VERSION(4, 0, 0)/>= KERNEL_VERSION(2, 6, 32)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/< KERNEL_VERSION(4,2,0)/< KERNEL_VERSION(2, 6, 30)/' src/wl/sys/wl_cfg80211_hybrid.c
EL7
而在EL7上，需要运行的是以下语句：
[user@host hybrid-wl]$ sed -i 's/ >= KERNEL_VERSION(3, 11, 0)/ >= KERNEL_VERSION(3, 10, 0)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/ >= KERNEL_VERSION(3, 15, 0)/ >= KERNEL_VERSION(3, 10, 0)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/ < KERNEL_VERSION(3, 18, 0)/ < KERNEL_VERSION(3, 9, 0)/' src/wl/sys/wl_cfg80211_hybrid.c
[user@host hybrid-wl]$ sed -i 's/ >= KERNEL_VERSION(4, 0, 0)/ >= KERNEL_VERSION(3, 10, 0)/' src/wl/sys/wl_cfg80211_hybrid.c
打补丁，再次编译
以下步骤在EL6和EL7上相同。
下载wl-kmod-fix-ioctl-handling.patch到/usr/local/src并运行
[user@host hybrid-wl]$ patch -p1 < ../wl-kmod-fix-ioctl-handling.patch
patching file src/wl/sys/wl_cfg80211_hybrid.c
Hunk #1 succeeded at 1467 (offset 17 lines).
patching file src/wl/sys/wl_linux.c
Hunk #1 succeeded at 1659 (offset 8 lines).
现在再次编译
[user@host hybrid-wl]$ make -C /lib/modules/`uname -r`/build/ M=`pwd`
这次我们得到的输出应该是这样：
make: Entering directory `/usr/src/kernels/2.6.32-573.7.1.el6.x86_64'
CFG80211 API is prefered for this kernel version
Using CFG80211 API
LD /usr/local/src/hybrid-wl/built-in.o
CC [M] /usr/local/src/hybrid-wl/src/shared/linux_osl.o
CC [M] /usr/local/src/hybrid-wl/src/wl/sys/wl_linux.o
CC [M] /usr/local/src/hybrid-wl/src/wl/sys/wl_iw.o
CC [M] /usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.o
/usr/local/src/hybrid-wl/src/wl/sys/wl_cfg80211_hybrid.c:1802: warning: initialization from incompatible pointer type
LD [M] /usr/local/src/hybrid-wl/wl.o
Building modules, stage 2.
CFG80211 API is prefered for this kernel version
Using CFG80211 API
MODPOST 1 modules
CC /usr/local/src/hybrid-wl/wl.mod.o
LD [M] /usr/local/src/hybrid-wl/wl.ko.unsigned
NO SIGN [M] /usr/local/src/hybrid-wl/wl.ko
make: Leaving directory `/usr/src/kernels/2.6.32-573.7.1.el6.x86_64'
之后可以去掉一些不必要的符号
[user@host hybrid-wl]$ strip --strip-debug wl.ko
至此，驱动已经编译完成，可以使用。
步骤四：将驱动载入内核
首先，移除已经存在的一些不可用的无线网卡驱动，这样才能载入新的。
[root@host ~]# modprobe -r bcm43xx
[root@host ~]# modprobe -r b43
[root@host ~]# modprobe -r b43legacy
[root@host ~]# modprobe -r ssb
[root@host ~]# modprobe -r bcma
[root@host ~]# modprobe -r brcmsmac
[root@host ~]# modprobe -r ndiswrapper
把驱动模块放在kernel能找到的地方
[root@host hybrid-wl]# cp -vi /usr/local/src/hybrid-wl/wl.ko /lib/modules/`uname -r`/extra/
然后运行
[root@host ~]# depmod $(uname -r)
[root@host hybrid-wl]# modprobe wl
如果没有报错就可以用啦。
步骤五：将驱动载入程序加入开机启动
编辑/etc/modprobe.d/blacklist.conf添加以下语句
blacklist bcm43xx
blacklist b43
blacklist b43legacy
blacklist bcma
blacklist brcmsmac
blacklist ssb
blacklist ndiswrapper
编辑/etc/sysconfig/modules/kmod-wl.modules写入以下内容
#!/bin/bash
for M in lib80211 cfg80211 wl; do
modprobe $M &>/dev/null
done
这样，驱动就会开机启动啦！