How to use Edimax EW-7811un-V2 WiFi dongle on STM32MP157A-DK1 Discovery Board ?

[Anna RAFFALLI]

Edimax EW-7811UN V2 WiFi dongle is not supported by default on OpenSTLinux distribution STM32MP15-Ecosystem-v3.0.0 release (Linux kernel version 5.10.10).
What are the steps to enable it on this release ?This article describes the steps to:

• Enable support of Edimax EW-7811UN V2 WiFi dongle in OpenSTLinux distribution 
• Bring up the wlan interface and connect to a WiFi network

1. Enable support of Edimax EW-7811UN V2 WiFi dongle

• Apply this patch from Linux 5.10.20 (this step will no more be necessary on release higher than STM32MP15-Ecosystem-v3.0.0)
• Re-compile the Linux kernel with the 8188eu driver in driver/staging folder (CONFIG_R8188EU=m)
• Get the rtl8188eufw.bin  firmware and copy it to the target rootfs in /lib/firmware/rtlwifi/

2. Bring up the wlan interface and connect to a WiFi network

This STM32PMU wiki page explains how to setup a WiFi connection on an STM32MP1 development board, but it does not exactly apply in case of the Edimax dongle.
Here are the commands to be ran in the target (STM32MP157A-DK1 Discovery Board with Edimax WiFi dongle) to bring up the wlan interface and connect to the WiFi network:
Only the first time:

Board $> mkdir -p /etc/wpa_supplicant/
Board $> wpa_passphrase SSID_OF_NETWORK PASSWORD_OF_NETWORK >> /etc/wpa_supplicant/wpa_supplicant-wlan0.conf

At every boot:

Board $> wpa_supplicant -i wlan0 -D wext -c /etc/wpa_supplicant/wpa_supplicant-wlan0.conf -B

Note: once you see "R8188EU: assoc success" and "wlan0: link becomes ready", it means that the WiFi interface bring-up is successful

Board $> dhclient wlan0

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