adding drivers to the kernel

adding drivers to the kernel

[Jim Abernathy]

If I need to add a driver for a networking device that should be in the 
3.0 kernel, but seems to be turned off, I usually follow the example in 
sections B.2.3 in the Development Manual. When I get to the stage of 
running bitbake linux-yocto -c menuconfig, I can search for my device 
with the "/" command and search for CONFIG_RTL8192CE and I find this:

Symbol: RTL8192CE [=n] │
│ Type : tristate │
│ Prompt: Realtek RTL8192CE/RTL8188CE Wireless Network Adapter │
│ Defined at drivers/net/wireless/rtlwifi/Kconfig:1 │
│ Depends on: NETDEVICES [=y] && WLAN [=y] && MAC80211 [=n] && PCI [=y] │
│ Location: │
│ -> Device Drivers │
│ -> Network device support (NETDEVICES [=y]) │
│ -> Wireless LAN (WLAN [=y]) │
│ Selects: FW_LOADER [=y] && RTLWIFI [=n] && RTL8192C_COMMON [=n]

However, I can't find this device where is should be or anywhere in the 
.config file. I've tried just adding the CONFIG_RTL8192CE=y to a config 
fragment file anyway and that didn't work. After building the image, the 
.config still didn't have the CONFIG_RTL8192CE=y. The 3.0 kernel should 
have support for the RTL8192CE devices.

Also if I manual add CONFIG_RTL8192CE=y to the .config file and then 
compile and build the kernel, the RTL8192CE parameter is removed from 
the .config file after the kernel build.

Any ideas?

Jim A

Re: adding drivers to the kernel

[Marc Ferland]

Jim Abernathy <jfabernathy@gmail.com> writes:

> If I need to add a driver for a networking device that should be in
> the 3.0 kernel, but seems to be turned off, I usually follow the
> example in sections B.2.3 in the Development Manual. When I get to the
> stage of running bitbake linux-yocto -c menuconfig, I can search for
> my device with the "/" command and search for CONFIG_RTL8192CE and I
> find this:
>
> Symbol: RTL8192CE [=n] │
> │ Type : tristate │
> │ Prompt: Realtek RTL8192CE/RTL8188CE Wireless Network Adapter │
> │ Defined at drivers/net/wireless/rtlwifi/Kconfig:1 │
> │ Depends on: NETDEVICES [=y] && WLAN [=y] && MAC80211 [=n] && PCI [=y] │
> │ Location: │
> │ -> Device Drivers │
> │ -> Network device support (NETDEVICES [=y]) │
> │ -> Wireless LAN (WLAN [=y]) │
> │ Selects: FW_LOADER [=y] && RTLWIFI [=n] && RTL8192C_COMMON [=n]
>
> However, I can't find this device where is should be or anywhere in
> the .config file. I've tried just adding the CONFIG_RTL8192CE=y to a
> config fragment file anyway and that didn't work. After building the
> image, the .config still didn't have the CONFIG_RTL8192CE=y. The 3.0
> kernel should have support for the RTL8192CE devices.
>
> Also if I manual add CONFIG_RTL8192CE=y to the .config file and then
> compile and build the kernel, the RTL8192CE parameter is removed from
> the .config file after the kernel build.
>
You probably need to enable MAC80211 first. Your RTL8192CE driver will
be selectable afterwards.
Marc

Re: adding drivers to the kernel

[Jim Abernathy]

On 08/23/2012 08:35 AM, Marc Ferland wrote:
> Jim Abernathy <jfabernathy@gmail.com> writes:
>
>> If I need to add a driver for a networking device that should be in
>> the 3.0 kernel, but seems to be turned off, I usually follow the
>> example in sections B.2.3 in the Development Manual. When I get to the
>> stage of running bitbake linux-yocto -c menuconfig, I can search for
>> my device with the "/" command and search for CONFIG_RTL8192CE and I
>> find this:
>>
>> Symbol: RTL8192CE [=n] │
>> │ Type : tristate │
>> │ Prompt: Realtek RTL8192CE/RTL8188CE Wireless Network Adapter │
>> │ Defined at drivers/net/wireless/rtlwifi/Kconfig:1 │
>> │ Depends on: NETDEVICES [=y] && WLAN [=y] && MAC80211 [=n] && PCI [=y] │
>> │ Location: │
>> │ -> Device Drivers │
>> │ -> Network device support (NETDEVICES [=y]) │
>> │ -> Wireless LAN (WLAN [=y]) │
>> │ Selects: FW_LOADER [=y] && RTLWIFI [=n] && RTL8192C_COMMON [=n]
>>
>> However, I can't find this device where is should be or anywhere in
>> the .config file. I've tried just adding the CONFIG_RTL8192CE=y to a
>> config fragment file anyway and that didn't work. After building the
>> image, the .config still didn't have the CONFIG_RTL8192CE=y. The 3.0
>> kernel should have support for the RTL8192CE devices.
>>
>> Also if I manual add CONFIG_RTL8192CE=y to the .config file and then
>> compile and build the kernel, the RTL8192CE parameter is removed from
>> the .config file after the kernel build.
>>
> You probably need to enable MAC80211 first. Your RTL8192CE driver will
> be selectable afterwards.
> Marc
You are correct. after I posted my question, I cheated and booted Ubuntu 
on the same hardware and saw the list of modules that lsmod showed were 
loaded to support my WiFi card.  my config fragment files now has:
CONFIG_RTL8192CE=y
CONFIG_RTL8192C_COMMON=y
CONFIG_RTLWIFI=y
CONFIG_MAC80211=y
CONFIG_CFG80211=y

It's still building, but at least the .config file now has all the right 
parameters in it and they didn't get deleted by the bitbake linux-yocto 
-c compile -f

Thanks,

Jim A

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