How to see runtime log on Rpi3 B+

[Tomasz Gajewski]

kimberly nNA <eft823177 at gmail.com> writes:

Hi,

> I modified and added some apps on demo.run
> The genode version is https://github.com/tomga/genode/tree/rpi3bplus_19.02

It's great that someone tries to use this :-).

> I tried this commands : 
> $ ./tool/create_builddir rpi3bplus 
> $ make run/demo KERNEL=hw
> This case successfully run on Rpi3 B+ 

It's even more great to hear that it is working.

> But I couldn't see the runtime log like as on x86_64 :
> ----------------------------------------------------------------------------------
> ...
> [init -> drivers] Error: Could not open ROM session for "config"
> [init -> drivers] Error: Uncaught exception of type 'Genode::Rom_connection::Rom_connection_failed'
> [init -> drivers] Warning: abort called - thread: ep
> [init] child "drivers" exited with exit value 1
> [init -> acpi_drv] Found MADT
> ...
> -----------------------------------------------------------------------------------
> Like the above example, sometimes I want to debug errors on Rpi.
> Can I see the runtime log on Rpi3 B+ ?
> If it can, how to set on putty ? (p.s. I used USB to TTL Serial Cable)

Some time ago Alexander Weidinger wrote on this list that it is
important to have in config.txt following:

   enable_uart=1
   init_uart_baud=115200
   init_uart_clock=3000000

and that last line is really important. I haven't really checked if it
works without it but definitely works with. Maybe it is the missing
part?

If you use u-boot you should see some logs from it first. Do you use it
and see logs?

> In putty configuration :
> serial line : /dev/ttyUSB0
> speed : 115200

115200 should work.

> I also tried speed : 9600
> But I still couldn't see runtime log.
>
> Maybe I have to refer to gpio_signal.run and then modify demo.run ?

I've never tested gpio_signal.run yet but for testing UART you should
probably start with run/log instead of run/demo. It's much smaller.

Some time ago I've started to write my first article to genodians.org
documenting all steps I've done to configure booting on RPI. Your
problem gives me motivation to finish it. I don't promise, but I'll try
to finish it in next few days.

Tomasz