Install drivers for RTL8812au for raspibian kernel 5.4.79-v71+ / RPI 4

Question

I have been trying for some days now to get an Alfa AWUS036ACS USB adapter installed on an RPI running Buster. This adapter uses the RTL8811au chipset but everyone seems to use the rtl8812au drivers.

The problem I seem to be having is monitor mode doesn't work with the standard drivers so a specific set of drivers needs to be used.

I have followed lots of instructions but this one seems to get the closest - Install drivers for RTL8812au for raspibian kernel 4.14.79-v7+ or 4.14.79.87-v7+?

However when I follow the instructions for the edited comment by Jake specific to Buster using dkms I get the following error when running command sed -i 's/^dkms build/ARCH=arm dkms build/' dkms-install.sh

The error being sed: can't read dkms-install.sh: No such file or directory

Not sure what to try. The install is going onto a fresh build of Buster with the only other addition of sudo apt update being run.

I presume it has something to do with the RPI4 being a 64bit platform?

Answer 1

I followed these instructions, Installation of RTL8812AU/21AU Wireless drivers, to the letter and the driver is now installed:

Download

$ git clone -b v5.6.4.2 https://github.com/aircrack-ng/rtl8812au.git
cd rtl*

Package / Build dependencies

$ sudo apt-get update
$ sudo apt-get install build-essential libelf-dev linux-headers-`uname -r`
$ sudo apt-get install raspberrypi-kernel-headers

Then run this step to change platform in Makefile, For RPI 1/2/3/ & 0/Zero:

$ sed -i 's/CONFIG_PLATFORM_I386_PC = y/CONFIG_PLATFORM_I386_PC = n/g' Makefile
$ sed -i 's/CONFIG_PLATFORM_ARM_RPI = n/CONFIG_PLATFORM_ARM_RPI = y/g' Makefile

But for RPI 3B+ & 4B you will need to run those below which builds the ARM64 arch driver:

$ sed -i 's/CONFIG_PLATFORM_I386_PC = y/CONFIG_PLATFORM_I386_PC = n/g' Makefile
$ sed -i 's/CONFIG_PLATFORM_ARM64_RPI = n/CONFIG_PLATFORM_ARM64_RPI = y/g' Makefile

In addition, if you receive an error message about unrecognized command line option ‘-mgeneral-regs-only’ (i.e., Raspbian Buster), you will need to run the following commands, then retry building and installing:

$ export ARCH=arm
$ sed -i 's/^MAKE="/MAKE="ARCH=arm\ /' dkms.conf

For building & installing the driver with 'make' use

$ make && make install