Shulou(Shulou.com)06/02 Report--

In this issue, the editor will bring you about how to carry out the Linux_WIFI driver experiment on the IMX6ULL development board. The article is rich in content and analyzes and describes for you from a professional point of view. I hope you can get something after reading this article.

1. The RTL8723 wifi module of the usb interface is used on the i.MX6ULL development board, and the schematic diagram is as follows:

We can see that the interface of the RTL8723 module is very simple. Only DP1 and DM1 are connected to the usb HUB chip, the communication circuit can be completed.

RTL8723 is the wifi chip of realtek. It has already provided the wifi driver source code, so we don't need to write it ourselves, just mention it.

The source code for the wifi driver is added to the Linux kernel for compilation.

1.1 add wifi drivers to the Linux kernel

First, get the wifi driver source code and put it in the Linux kernel drivers/net/wireless directory, as shown below:

The contents of the rtl8723BU directory are as follows:

The Kconfig file is the configuration file of the rtl8723 driver, so you can choose whether to compile or not through the graphical configuration interface of the Linux kernel.

WIFI driver. The contents of the Kconfig file are as follows:

Config RTL8723BU

Tristate "Realtek 8723B USB WiFi"

Depends on USB

-help

Help message of RTL8723BU

When you finish adding the rtl8723 wifi driver, you need to modify the Kconfig and Makefile one level above.

Modify the drivers/net/wireless/Kconfig and add the following:

Source "drivers/net/wireless/rtl8723BU/Kconfig"

After the addition is completed, it is as follows:

After the addition is completed, the configuration option for rtl8723 will not appear on the driver configuration interface of the Linux kernel.

Modify the drivers/net/wireless/Makefile file by adding the following:

Obj-$ (CONFIG_RTL8723BU) + = rtl8723BU/

After modification, it is as follows:

1.2 configure the Linux kernel

After adding the rtl8723 wifi driver and modifying the configuration file, you need to configure it in the Linux kernel.

1. Configure devices that support USB

The Linux kernel configuration path is as follows:

Device Drivers->

USB support->

EHCI HCD (USB 2.0) support

ChipIdea Highspeed Dual Role Controller

ChipIdea device controller

ChipIdea host controller

The configuration is completed as shown in the following figure:

2. Configure devices that support wifi

The Linux kernel configuration path is as follows:

Device Drivers->

Network device support->

Wireless LAN->

IEEE 802.11 for Host AP (Prism2/2.5/3 and WEP/TKIP/CCMP)

Support downloading firmware images with Host AP driver

Support for non-volatile firmware download

The configuration is completed as shown in the following figure:

3. The configuration supports IEEE 802.11.

The Linux kernel configuration path is as follows:

Networking support->

-*-Wireless->

Cfg80211 wireless extensions compatibility

Generic IEEE 802.11 Networking Stack (mac80211)

The configuration is completed as shown in the following figure:

4. Configure rtl8723 wifi driver

The Linux kernel configuration path is as follows:

Device Drivers->

Network device support->

Wireless LAN->

Realtek 8723B USB WiFi

The configuration result is shown in the figure:

Compile the driver of the rtl8723 wifi module directly into the kernel.

After the above Linux kernel configuration is complete, recompile the kernel to generate zImage, and start the development board using the new zImage.

1.3 rtl8723 wifi module driver testing

Use the new zImage image to launch the development board, and the following information will be printed during system startup:

The figure above shows that the driver of the rtl8723 wifi module was used during Linux system startup. Use "ifconfig-a" when the driver is started.

Command to check whether the wlan Nic exists, and the result is shown in the following figure:

You can see that there is a wlan0 device, which is the network card device corresponding to the rtl8723 wifi module. Indicates that the driver test is normal, but

If you want to connect to the Internet, you need third-party components. Let's take a look at how to use third-party components for networking testing.

The above is the editor for you to share how to carry out the IMX6ULL development board Linux_WIFI driver experiment, if you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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