[Buildroot] /dev/ttyprinkt usage in BR

[Buildroot] /dev/ttyprinkt usage in BR

[Yegor Yefremov]

As of kernel 2.6.37 there is a new pseudo tty device /dev/ttyprinkt, that can make user output through pritnk() routine. How can it be used in BR? What entries should /etc/inittab contain to redirect the console output to /dev/ttyprinkt?

Best regards,
Yegor

[Buildroot] /dev/ttyprinkt usage in BR

[Peter Korsgaard]

>>>>> "Yegor" == Yegor Yefremov <yegor_sub1@visionsystems.de> writes:

 Yegor> As of kernel 2.6.37 there is a new pseudo tty device
 Yegor> /dev/ttyprinkt, that can make user output through pritnk()
 Yegor> routine. How can it be used in BR? What entries should
 Yegor> /etc/inittab contain to redirect the console output to
 Yegor> /dev/ttyprinkt?

I haven't used it yet, but I guess the only thing you have to do to get
all console output though it is to use devtmpfs (or add the device node
in device_table.txt), and tell init to use it as console. Looking at the
busybox init code, I see it gets the console device from the CONSOLE or
console environment variables, so you would just have to add
CONSOLE=/dev/ttyprintk to the kernel commandline.

Using console=/dev/ttyprintk will probably cause strange behaviour as
that presumably creates a loop, where every kernel message is sent back
in and reprinted.

But again, completely untested.

-- 
Bye, Peter Korsgaard

[Buildroot] /dev/ttyprinkt usage in BR

[Yegor Yefremov]

>  Yegor> As of kernel 2.6.37 there is a new pseudo tty device
>  Yegor> /dev/ttyprinkt, that can make user output through pritnk()
>  Yegor> routine. How can it be used in BR? What entries should
>  Yegor> /etc/inittab contain to redirect the console output to
>  Yegor> /dev/ttyprinkt?
>
> I haven't used it yet, but I guess the only thing you have to do to get
> all console output though it is to use devtmpfs (or add the device node
> in device_table.txt), and tell init to use it as console. Looking at the
> busybox init code, I see it gets the console device from the CONSOLE or
> console environment variables, so you would just have to add
> CONSOLE=/dev/ttyprintk to the kernel commandline.

Device creation is not a problem. If I change the console in /etc/inittab from ttyAM0 to ttyprintk I get

[U]
[U]
[U] Welcome to Buildroot
[U]                    

but no prompt.

Best regards,
Yegor