Romain and I spent the last few days trying to get the WiFi dongle to work with the SOM.
However, several issues had to be overcome in order to succeed in doing this.
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
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.
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
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.
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