DKMS全称是Dynamic Kernel Module SupportLinux模块和内核是有依赖关系的，如果遇到因为发行版更新造成的内核版本的变动，之前编译的模块是无法继续使用的，我们只能手动再编译一遍。DKMS可以帮我们维护内核外的这些驱动程序，在内核版本变动之后可以自动重新生成新的模块。

安装dkms

sudo apt-get install dkms

dkms的使用流程如下:

                                                                     uninstall
                                                           ---------------------------
                                                           -                         -
                                                           V                         -
    ---------------         ---------------         ---------------         -------------------
    -             -  add    -             - build   -             - install -                 -
    - Not in tree - ------> - Added State - ------> - Built State - ------> - Installed State -
    -             -         -             -         -             -         -                 -
    ---------------         ---------------         ---------------         -------------------
           ^                      -                        -                        -
           -                      -                        -                        -
           --------------------------------------------------------------------------
                                            remove
                                            

add、build、install、uninstall和remove

例如：

$ dkms status 
virtualbox, 4.3.10, 3.13.0-49-generic, x86_64: installed

dkms要求代码的目录必须以 <module>-<module-version> 的格式命名, 例如： hello-0.1

rtlwifi代码的github地址为: http://github.com/lwfinger/rtlwifi_new.git

将下载的代码拷贝到/usr/src

例如：

$ ls /usr/src/
linux-headers-3.13.0-49          rtlwifi-1.0
linux-headers-3.13.0-49-generic  virtualbox-4.3.10 

还需要在rtlwifi-1.0中新建一个文件dkms.conf

PACKAGE_NAME="rtlwifi"
PACKAGE_VERSION="1.0"
CLEAN="make clean"
BUILT_MODULE_NAME[0]="rtlwifi"
BUILT_MODULE_LOCATION[0]="."
DEST_MODULE_LOCATION[0]="kernel/drivers/net/wireless/rtlwifi"
BUILT_MODULE_NAME[1]="rtl_pci"
BUILT_MODULE_LOCATION[1]="."
DEST_MODULE_LOCATION[1]="kernel/drivers/net/wireless/rtlwifi"
BUILT_MODULE_NAME[2]="rtl_usb"
BUILT_MODULE_LOCATION[2]="."
DEST_MODULE_LOCATION[2]="kernel/drivers/net/wireless/rtlwifi"
BUILT_MODULE_NAME[3]="btcoexist"
BUILT_MODULE_LOCATION[3]="btcoexist"
DEST_MODULE_LOCATION[3]="kernel/drivers/net/wireless/rtlwifi/btcoexist"
BUILT_MODULE_NAME[4]="rtl8723be"
BUILT_MODULE_LOCATION[4]="rtl8723be"
DEST_MODULE_LOCATION[4]="kernel/drivers/net/wireless/rtlwifi/rtl8723be"
AUTOINSTALL="yes"

PACKAGE_NAME和PACKAGE_VERSION和文件夹的命名是一致的。

D

ESTMODULELOCATION[0]用来设定模块安装的目的地址，本例是“/lib/module/$(KVERSION)/updates” DESTMODULELOCATION[#] 在下面这些发行版中被忽略：

• Fedora Core 6 and higher, Red Hat Enterprise Linux 5 and higher *Novell SuSE Linux Enterprise Server 10 and higher, Novell SuSE Linux10.0 and higher, and Ubuntu

Instead , the proper distribution-specific directory is used.

AUTOINSTALL=“yes”表示在Linux引导之后DKMS会自动对这个模块执行Build和Install的动作，当然如果模块已经处于该状态的话，相应的动作是不用再执行的。

sudo dkms add -m rtlwifi -v 1.0

其中-m指定module的名字， -v 指定module version 所以rtlwifi的源文件路径为： /usr/src/rtlwifi-1.0

$ sudo dkms add -m rtlwifi -v 1.0

Creating symlink /var/lib/dkms/rtlwifi/1.0/source ->
                 /usr/src/rtlwifi-1.0

DKMS: add completed. 

查看dkms的状态：

$ dkms status 
rtlwifi, 1.0: added
virtualbox, 4.3.10, 3.13.0-49-generic, x86_64: installed 

可以看到rtlwifi的状态为added

sudo dkms build -m rtlwifi -v 1.0

Kernel preparation unnecessary for this kernel.  Skipping...

Building module:
cleaning build area....
make KERNELRELEASE=3.13.0-49-generic -C /lib/modules/3.13.0-49-generic/build M=/var/lib/dkms/rtlwifi/1.0/build....................
cleaning build area....

DKMS: build completed.

查看dkms状态：

$ dkms status 
rtlwifi, 1.0, 3.13.0-49-generic, x86_64: built
virtualbox, 4.3.10, 3.13.0-49-generic, x86_64: installed 

rtlwifi的状态为built

生成的ko模块位于：

/var/lib/dkms/rtlwifi/1.0/3.13.0-49-generic/x86_64/module

$ sudo dkms install --force -m rtlwifi -v 1.0

rtlwifi:
Running module version sanity check.
 - Original module
 - Installation
   - Installing to /lib/modules/3.13.0-49-generic/updates/dkms/

rtl_pci.ko:
Running module version sanity check.
 - Original module
 - Installation
   - Installing to /lib/modules/3.13.0-49-generic/updates/dkms/

rtl_usb.ko:
Running module version sanity check.
 - Original module
 - Installation
   - Installing to /lib/modules/3.13.0-49-generic/updates/dkms/

btcoexist.ko:
Running module version sanity check.
 - Original module
 - Installation
   - Installing to /lib/modules/3.13.0-49-generic/updates/dkms/

btcoexist.ko:
Running module version sanity check.
 - Original module
 - Multiple same named modules!
   - 2 named btcoexist.ko in /lib/modules/3.13.0-49-generic/
 - Installation
   - Installing to /lib/modules/3.13.0-49-generic/updates/dkms/

rtl8723be.ko:
Running module version sanity check.
 - Original module
 - Installation
   - Installing to /lib/modules/3.13.0-49-generic/updates/dkms/

depmod....

DKMS: install completed.

查看dkms 状态：

$ dkms status 
rtlwifi, 1.0, 3.13.0-49-generic, x86_64: installed
virtualbox, 4.3.10, 3.13.0-49-generic, x86_64: installed 

从/lib/modules下移除:

sudo dkms uninstall -m rtlwifi -v 1.0

从/var/lib/dkms下彻底删除

sudo dkms remove -m rtlwifi -v 1.0 –all