Beaglebone AI - no USB virtual serial port and RAM size is less than 1G

I’ve flashed the Beaglebone AI board with Debian Buster IoT TIDL Image 2020-04-06 (listed on “latest images” webpage).
After boot, there is no usb serial port in the Windows device manager, like it used to be with Beaglebone Black.
Is it intentional? How can I enable/disable the USB virtual serial port on Beaglebone family?

In addition, free -m command says:

              total        used        free      shared  buff/cache   available
Mem:            612         142         312           4         158         452
Swap:             0           0           0

Why there is 612M total memory instead of 1G?

Found the answer here: Beaglebone AI Memory 1GB Ram? - Forum - BeagleBoard - element14 Community, but unfortunately the link to the original topic there is broken. Some more info is here: Getting started with the BeagleBone AI, but I don’t know if it’s up to date.

Memory is taken by the DSP/etc in the TIDL examples…

for USB please retest with the latest snapshot: