Driving me crazy

Romain and I spent the last few days trying to get the WiFi dongle to work with the SOM.

The little fella

However, several issues had to be overcome in order to succeed in doing this.

Overcurrent detection

Overcurrent detection had to be disabled for USB devices to be detected by the SOM.

WEXT and cfg80211

For the driver to work, wext and cfg80211 drivers have to be enabled in the configuration of Yocto. We found this out because the driver would not work. Fortunately, we stumbled upon this document from Intel.

Compile the correct driver

A confusion between the driver of our dongle (rtl8188eu) and the driver of cyL3D’s defunct dongle (rtl8812au) wasted a good amount of our time.… Read more

Build your own Linux for LitSpin

Today, I will teach you how to bake a Linux for your LitSpin project

Requirements needed

  • A tested Linux distribution (list). For this recipe, Ubuntu 19.10 seems to work even if it is not tested
  • A lot of packages. Here the list depending on your distribution

Tools needed

Clone those repositories in the same working directory

Creation of the meta-litspin layer

With the different tools, we can build a Linux distribution for the MCV evaluation kit (MCVEVK) and the MCV development board (MCVEVP).… Read more

#TeamTrees

With Nathan, we work a lot on the creation of the Linux distribution. On my side, I am working on how to add an sd card on an SPI bus and Nathan is working on the driver for the USB WiFi Dongle.

Device tree

An SD card can not be detected and set automatically like a USB device. We have to tell Linux there is a micro SD host on an SPI bus. We have to put a micro SD host on an SPI bus because the eMMC bus is already taken by the Flash. To tell Linux, there is a micro SD host on the SPI bus, the simplest method is to add it in the device tree blob.… Read more

Alea Yocto est

We need to build the disk image for the MCV SoM. To do this we have two options given by Aries, the SoM manufacturer. We can use Buildroot or Yocto.

Yocto

We decided to test Yocto first. Tarik Graba advised us to use it and a previous group who works with the same SoM used it too.

This project is a cross-compilation framework based on recipes. Every recipe contains a list of dependencies and a set of instructions (like a real recipe). The interesting point is the sources needed in a recipe can be directly downloaded online. So if some dependencies are missing, they will be automatically downloaded.… Read more