# Realtek RTL8811CU/RTL8821CU version 5.4.1 USB wifi adapter driver for Linux 4.20.x
Before build this driver make sure `make` , `gcc` , `linux-header` and `git` have been installed.
## First, clone this repository
```
git clone https://github.com/brektrou/rtl8821CU.git
```
## Build and install with DKMS
DKMS is a system which will automatically recompile and install a kernel module when a new kernel gets installed or updated. To make use of DKMS, install the dkms package.
### Debian/Ubuntu:
```
sudo apt-get install dkms
```
### Arch Linux/Manjaro:
```
sudo pacman -S dkms
```
To make use of the **DKMS** feature with this project, do the following:
```
DRV_NAME=rtl8821CU
DRV_VERSION=5.4.1
sudo cp -r ${DRV_NAME} /usr/src/${DRV_NAME}-${DRV_VERSION}
sudo chown -hRv root:root /usr/src/${DRV_NAME}-${DRV_VERSION}
sudo dkms add -m ${DRV_NAME} -v ${DRV_VERSION}
sudo dkms build -m ${DRV_NAME} -v ${DRV_VERSION}
sudo dkms install -m ${DRV_NAME} -v ${DRV_VERSION}
```
If you later on want to remove it again, do the following:
```
DRV_NAME=rtl8821CU
DRV_VERSION=5.4.1
sudo dkms remove ${DRV_NAME}/${DRV_VERSION} --all
```
## Build and install without DKMS
Use following commands:
```
cd rtl8821CU
make
sudo make install
```
## Checking installed driver
If you successfully install the driver, the driver is installed on `/lib/modules/<linux version>/kernel/drivers/net/wireless/realtek/rtl8821cu` . Check the driver with the `ls` command:
```
ls /lib/modules/$(uname -r)/kernel/drivers/net/wireless/realtek/rtl8821cu
```
Make sure `8821cu.ko` file present on that directory
Check with **DKMS** :
``
sudo dkms status
``
## Raspberry Pi
To build this driver on Raspberry Pi you need to set correct platform in Makefile.
Change
```
CONFIG_PLATFORM_I386_PC = y
CONFIG_PLATFORM_ARM_RPI = n
CONFIG_PLATFORM_ARM_RPI3 = n
```
to
```
CONFIG_PLATFORM_I386_PC = n
CONFIG_PLATFORM_ARM_RPI = y
CONFIG_PLATFORM_ARM_RPI3 = n
```
For the Raspberry Pi 3 you need to change it to
```
CONFIG_PLATFORM_I386_PC = n
CONFIG_PLATFORM_ARM_RPI = n
CONFIG_PLATFORM_ARM_RPI3 = y
```
