Pine64-LTS and UART ports

[Kaya Saman]

On 6/23/19 10:57 PM, Milan Obuch wrote:
> On Sun, 23 Jun 2019 21:42:16 +0100
> Kaya Saman <kayasaman at optiplex-networks.com> wrote:
>
>> Hi,
>>
>> I've attached an RS232c converter board to UART2 on my Pine64-LTS
>> board. I followed the pinout diagrams from here:
>>
> [ snip - no comment on this all ]
>
>> Based on my reading I created a 'hints' file for it:
>>
>> /boot/device.hints
>> hint.uart.2.disabled="0"
>>
>> but I'm not sure if this is correct?
>>
> Hi,
>
> short comment - in arm world, there is no device.hints file used, it is
> moved into dtb file. You should use overlay to enable uart2, which will
> then be used in /boot/loader.conf file - there should be line
>
> fdt_overlays="sun50i-a64-sid,sun50i-a64-ths,sun50i-a64-timer,sun50i-a64-opp"
>
> I did not tried it myself yet, so I can't write exactly what to use,
> important part in dtso file you should create is
>
> &uart2 { status = "okay";
> }
>
> because uart2 is disabled in shipped dtb. Look in dts overlays
> directories for some examples, maybe you could search in this mailing
> list archive, too... or someone with more knowledge could tell more.
>
> Regards,
> Milan


Thanks Milan for the tip!!


I am now going through these links:

https://forums.freebsd.org/threads/fdt-overlays-in-freebsd.52530/

http://freebsd.1045724.x6.nabble.com/Allwinner-dtb-overlays-on-CURRENT-Also-flashrom-SPI-td6271021.html


There doesn't seem to be too much information on how to create the 
Overlays. I found the .dtso files in the /usr/src/sys directory so I am 
guessing that one needs to compile the Overlays into the kernel?


Regards,


Kaya