MyNewt: NimBLE: Does BD_ADDR have to be unique?

[Pritish Gandhi]

Hi all,
I have a bunch of nrf52dk EVBs that I'm running the sample bleprph app on
and I noticed that all the device seems to have the same BD_ADDR (All
0x0a's). Doesn't each device need to have a unique BD_ADDR and shouldn't
that come from the BLE controller?
I see that the bls_hs_startup_read_bd_addr() always returns with a BD_ADDR
of all 0xa's. Does that mean that this device requires us to self program
the BD_ADDR?
Thanks,
Pritish