Yocto kernel installed if installing Ubuntu 16.04 without swap parition on Joule

[Forrest Sheng Bao]

Hi, I am not sure whether this is the right place to report the bug but this is the closest place I can find.

I am installing Ubuntu 16.04.2 (or Xubuntu 16.04.2) on my Intel Joule 570x docked on an Expansion Board. If I do not specify any swap partition, i.e., just one partition for root directory /, then a kernel of version 4.4.15-yocto-standard-x86_64 is installed instead of a generic 4.8.0-36 kernel that is the default one of Ubuntu 16.04.2.

This Yocto kernel has the driver for serial console of Joule, i.e., /dev/ttyS2. However, it has no module, i.e., lsmod returns nothing.

If I let Ubuntu or Xubuntu installation program automatically prepare the eMMC harddrive, then a swap partition will be created and the kernel to be installed will be 4.8.0-36 generic, which does not support /dev/ttyS2.

Note that the Ubuntu installation image is not from tuchuck (http://people.canonical.com/~platform/snappy/tuchuck/desktop-final/). I just use regular desktop versions. But it is really strange to me that the installation program changes the kernel in this way, and more importantly, the Yocto kernel has no mod.

Any clue?