4.2.2 Adding WILC Driver Support to Kernel

Clone the linux4microchip GitHub linux kernel repository by using the following command:
```
$ git clone https://github.com/linux4microchip/linux.git
```
Move to the kernel directory and export the toolchain path by using the following command:
```
export CROSS_COMPILE=arm-linux-gnueabi-
```
Configure the kernel by using the following command:
```
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- sama5_defconfig
```
Modify the default kernel configuration using the following menuconfig command:
```
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig
```
Select the ATWILC driver module, from the GUI selection window:
1. Navigate to Device Drivers > Network device support > Wireless LAN.
2. Press M to modularize WILC SDIO to include the module during runtime.
3. Save the configuration.
Include the cfg80211 as an inbuild module to the kernel from the GUI selection window by performing the following steps:
1. Navigate to Networking support > wireless.
2. Press * to include the cfg80211 – wireless configuration API module to the kernel.
3. Save the configuration.
Build the kernel using the following command:
```
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- zImage
```
Note: zImage is available in arch/arm/boot directory.
Build the modules using the following command:
```
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- modules
```
Note: wilc-sdio.ko file is available in driver/net/wireless/microchip/wilc1000 directory.
Build the .dtb file using the following command:
```
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- at91-sama5d3_xplained.dtb
```
Note: The at91-sama5d3_xplained.dtb file is available in arch/arm/boot/dts directory.