Skip to contentSkip to conversation

/dev/ttyprinkt usage in BR

Buildroot Yegor Yefremov 2 participants 3 messages Jan 12, 2011

lore
Share & tools
lore
#0 lore raw

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

#1 lore raw
Quoted 1 line
Quoted 1 line
Quoted 1 line
Quoted 1 line
Quoted 1 line

"Yegor" == Yegor Yefremov <[email protected]> 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.

Signature · 1 line
Bye, Peter Korsgaard
#2 lore raw
Quoted 7 lines

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?

Quoted 6 lines

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