rp2470 strange serial console behaviour
On 12/04/2017 03:54 PM, Helge Deller wrote:
Not sure if console output on a serial port of an rp3440 or related
machines needs to be "consumed" by a terminal to continue. But I've
seen something similar on my rp2470 (with GSP), where I needed to
hit the enter key multiple times to continue the boot process, each
time another few messages would appear on my terminal, but no
output and no progress if I I didn't hit the enter key. Systemd was
already running at this time. Strange behaviour.
Yes, I see this strange behavior as well. I think it's caused by
Later I remembered that I also tried without systemd in the past, and it
still happened, although I needed to perform much less keystrokes to
finish booting with System V init compared to systemd. But still, the
machine "hanged" (e.g. no sshd running) without manual intervention. I
today again tried with systemd removed as per , but same situation as
in my memory.
A workaround to get the rp2470 booting through automatically and still
have a console running on ttyS0 after the boot has finished, is to use
two console statements in the kernel command line and place the serial
console first, e.g.:
[...] console=ttyS0,9600n8 console=tty0 [...]
The last console statement will win.
But systemd will evaluate both console statements and after the boot is
completed there's a getty running on the serial console. With System V
init the serial console needs to be configured in `/etc/inittab` AFAIR.
It's still a workaround and one cannot follow all of the console
messages, but at least the machine boots through automatically.