Re: [PATCH] tty: Add NULL TTY driver

From: Enrico Weigelt, metux IT consult
Date: Fri Apr 05 2019 - 08:33:22 EST


On 05.04.19 11:00, Vincent Whitchurch wrote:
> On Fri, Apr 05, 2019 at 10:39:43AM +0200, Enrico Weigelt, metux IT consult wrote:
>> On 03.04.19 16:11, Vincent Whitchurch wrote:
>>
>>> Especially on embedded systems, it would be convenient to have a simple
>>> way to disable the console (both for kernel and userspace) on a system
>>> which normally uses it, to free up the UART for other things.
>>
>> Just symlinking to /dev/null does not work ?
>
> No, /dev/null does not support the TTY ioctls.

hmm, wo (which programs) do you need, that really need them ?

>> OTOH, if you're introducing a dummy console, wouldn't a ringbuffer that,
>> can be read out later, a better option ?
>
> There is already a ttyprintk driver in mainline to send these messages
> to the printk ring buffer if one is actually intrested in what is
> written to the console. There's no option to enable it via console= in
> mainline but I have a patch for that too.

Great. IMHO, that would be the better way.


--mtx

--
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
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