rpi3 and Adafruit GPS Hat

[Per olof Ljungmark]

On 07/18/18 19:01, Diane Bruce wrote:
> On Wed, Jul 18, 2018 at 05:10:16PM +0200, Per olof Ljungmark wrote:
>> Being a complete newbie to arm I thought a nice project would be to
>> build a NTP server with the parts in the subject line.
>>
>> Unfortunately I have almost no idea where to start, it seems FreeBSD for
>> arm have shifted around quite a bit, almost none of the googled pages I
>> find has relevance, and to add insult to injury, the Pi project
>> apparently shifted the serial ports around for the Pi3.
>>
>> What I need to achieve,
>>
>> - Stop the kernel to use the uart for console output (I have ethernet
>> and HDMI connected)
> 
> No need.
> 
> change your config.txt
> 
> #dtoverlay=pi3-disable-bt
> device_tree_address=0x4000
> kernel=u-boot.bin
> enable_uart=1
> 
> This moves the console port to the less capable micro uart port
> this will free up the good uart (the pl011 device) as /dev/ttyu0
> 
> Remove the pi3-disable-dt in config.txt
> enable_uart=1 is needed.
> 
>> VERY grateful if someone that knows better can give me a push in the
>> right direction for up to date information.
> ..
> 
> This is assuming you use FreeBSD-12 (Head of tree)
> 

Yes, 12.0-CURRENT #2 r336461.

Unfortunately your advice did not solve the problem, when the hat is
attached it sends NMEA sequences to the u-boot loader making it
impossible to boot further, just like it is described in this thread:

http://freebsd.1045724.x6.nabble.com/Adding-a-GPS-Module-hat-shield-on-a-Raspberry-Pi-td6236680.html