[Buildroot] [PATCH] systemd: let getty instead of serial-getty handle /dev/console

[Floris Bos]

On 09/22/2016 08:50 PM, Peter Seiderer wrote:
> Hello Floris,
>
> On Wed, 21 Sep 2016 23:47:02 +0200, Floris Bos <bos at je-eigen-domein.nl> wrote:
>
>> On 09/21/2016 10:05 PM, Peter Seiderer wrote:
>>> Hello *,
>>>
>>> On Wed, 21 Sep 2016 09:01:37 +0200, Peter Korsgaard <peter at korsgaard.com> wrote:
>>>
>>>>>>>>> "Yann" == Yann E MORIN <yann.morin.1998 at free.fr> writes:
>>>>    > Floris, All,
>>>>    > On 2016-09-09 18:10 +0200, Floris Bos spake thusly:
>>>>    >> The serial-getty unit depends on dev-%i.device which does not
>>>>    >> seem to be created for /dev/console
>>>>    >> Workaround this by letting normal getty unit handle things
>>>>    >> if BR2_TARGET_GENERIC_GETTY_PORT is set to 'console'
>>>>    >>
>>>>    >> Signed-off-by: Floris Bos <bos at je-eigen-domein.nl>
>>>>
>>>>    > I haven't tested that, but I think this is OK just on principle.
>>>>
>>>>    > I just wonder if that behaves correctly when console is a serial line or
>>>>    > anything else (e.g. a VT on HDMI, or through a debug channel...)
>>>>
>>>> Yeah, me too. Does anybody know what the difference exactly is between
>>>> getty/serial-getty, and when one should be used over the other?
>>>>
>>> Tested for the rpi3/glibc/systemd case and failed: I get a doubled
>>> (and unusable) ' Welcome to Buildroot/buildroot login:' on serial and
>>> no login on hdmi...
>> Empty cmdline.txt will give hdmi.
>>
>> Recall you need "console=serial0,115200 console=tty1" with tty1 last in
>> cmdline.txt if you want them simultaneous.
> Changed cmdline.txt to:
>
> 	root=/dev/mmcblk0p2 rootwait console=ttyAMA0,115200 console=tty1
>
> Which gives me two (functional) logins on serial and hdmi.
>
> But I think changing package/rpi-firmware/cmdline.txt unconditional will
> break the other Init systems, see commit log from last patch touching
> cmdline.txt ([1):
>
>    ...change BR2_TARGET_GENERIC_GETTY_PORT to "console", so it starts a
>    getty on the last console= passed to the kernel, ttyAMA0...

Will withdraw my patch then, and wait for someone else to come up with a 
better solution.

I think the one-size-fits all cmdline.txt that listens to both on HDMI 
and serial console by default makes things too complicated anyway.


Yours sincerely,

Floris Bos