Re: Fwd: NetBSD on rpi0-2w

On Tue, 23 Apr 2024, Michael van Elst wrote:
>> Hello Michael,
>
>>  MvE> There is also the conflict between bluetooth and console.  Both
>>    > want the "full" UART for performance (FIFO) and constant baud-
>>    > rate.  You have to chose between several compromises.
>
>>    Is this just on the Zero 2 W or on other Raspberry Pi boards too?
>> I've been thinking of picking up some 3A+ boards for WiFi and Blue-
>> tooth experiments.
>
> That's on rpi0-4, not sure about rpi5.
>
> On rpi0-3, you only have two UARTs, one has no FIFO and may change
> baudrate.
>
> On rpi4 there are 4 more UARTs, but their usage is limited, so
> you cannot use these for Bluetooth or as regular console.

There is no conflict, the primary uart (UART0:PL011) is used by
the bluetooth module and the secondary (UART1:mini UART) by the
console. The dts I posted to the list and the one existing for the
rpi3 make netbsd select the secondary uart for the console without
any problem. The only problems you'll have are related to some bug
other users have reported running some programs specially under
sudo on the console.

With the rpi4-400 the situation is better, 5 full featured PL011
uart, 1 mini UART. You should be able to use bluetooth in any of the
PL011 editing the dtb or using overlays.

In fact you should be able to use bluetooth with the mini UARTS,
just with a smaller baud rate, if the netbsd driver supports it,
of course. I haven't had time to test bluetooth with these boards.

Ramiro, one of the pros of the raspberry pi boards over other boards
(no matter the fruit) is the excelent documentation. I advice you
to take a look at the official documentation (no tutorials or copy
-paste blogs), read it with pacient differenciating the content
realted only to linux drivers. Note that some legacy options in
config.txt are still relevant to netbsd.

Regards,
adr