Changing the tty/UART of busybox

Changing the tty/UART of busybox

[Jakob Hasse]

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Hello,

we need to change the tty on which busybox is sitting. Right now I could 
change the UART for the kernel and all program output after the boot to 
our favorite UART (via kernel cmd line). But the login promt and all 
interaction with the device is still on the old UART. So I guess it's a 
busybox configuration issue. Furthermore, when I try tty after login, it 
gives me: /dev/ttymxc4 (we want to use ttymx1).

I looked here https://busybox.net/downloads/BusyBox.html and in 
menuconfig for an option to change the UART interface but couldn't find 
any. Furthermore I added

|::respawn:/sbin/getty -L ttymxc1 115200 vt100 |

and this

|ttymxc1::respawn:/sbin/getty -L ttymxc1 115200 vt100|

to inittab to change the UART with no luck.
Could someone here point me to documentation or give me a hint to achive 
this?

Thanks in advance, all the Best,
Jakob

-- 
Jakob Hasse
Software Developement

E: jakob.hasse@smart-home-technology.ch
T: +41 44 552 02 66

Smart Home Technology GmbH
www.smart-home-technology.ch


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Re: Changing the tty/UART of busybox

[Maxin B. John]

Hi Jakob,

>On Wed, Feb 28, 2018 at 11:15:42AM +0100, Jakob Hasse wrote:
>
>Hello,
>
>we need to change the tty on which busybox is sitting. Right now I could change
> the UART for the kernel and all program output after the boot to our favorite 
> UART (via kernel cmd line). But the login promt and all interaction with the 
> device is still on the old UART. So I guess it's a busybox configuration issue.
> Furthermore, when I try tty after login, it gives me: /dev/ttymxc4 (we want to use ttymx1).
>
>I looked here https://busybox.net/downloads/BusyBox.html and in menuconfig
> for an option to change the UART interface but couldn't find any. Furthermore I added
>
>::respawn:/sbin/getty -L ttymxc1 115200 vt100
>
>and this
>
>ttymxc1::respawn:/sbin/getty -L ttymxc1 115200 vt100
>
>to inittab to change the UART with no luck.
>Could someone here point me to documentation or give me a hint to achive this?

Generally, the console setting comes from our <machine>.conf. eg:
for beaglebone:
./meta-yocto-bsp/conf/machine/beaglebone-yocto.conf:
SERIAL_CONSOLE = "115200 ttyO0"

This gets processed in bitbake.conf:
SERIAL_CONSOLES ??= "${@d.getVar('SERIAL_CONSOLE').replace(' ', ';')}"

later, based on the init manager:
busybox, systemd-serialgetty, or sysvinit-inittab use it.

In this case, updating the "<machine>.conf" should help.

>Thanks in advance, all the Best,
>Jakob
>
>-- 
>Jakob Hasse
>Software Developement
>
>E: jakob.hasse@smart-home-technology.ch
>T: +41 44 552 02 66 
>
>Smart Home Technology GmbH
>www.smart-home-technology.ch

Best Regards,
Maxin

Re: Changing the tty/UART of busybox

[Jakob Hasse]

Hi Maxin,

thanks, this worked!

All the Best,
Jakob

On 28.02.2018 14:13, Maxin B. John wrote:
> Hi Jakob,
>
>> On Wed, Feb 28, 2018 at 11:15:42AM +0100, Jakob Hasse wrote:
>>
>> Hello,
>>
>> we need to change the tty on which busybox is sitting. Right now I could change
>> the UART for the kernel and all program output after the boot to our favorite
>> UART (via kernel cmd line). But the login promt and all interaction with the
>> device is still on the old UART. So I guess it's a busybox configuration issue.
>> Furthermore, when I try tty after login, it gives me: /dev/ttymxc4 (we want to use ttymx1).
>>
>> I looked here https://busybox.net/downloads/BusyBox.html and in menuconfig
>> for an option to change the UART interface but couldn't find any. Furthermore I added
>>
>> ::respawn:/sbin/getty -L ttymxc1 115200 vt100
>>
>> and this
>>
>> ttymxc1::respawn:/sbin/getty -L ttymxc1 115200 vt100
>>
>> to inittab to change the UART with no luck.
>> Could someone here point me to documentation or give me a hint to achive this?
> Generally, the console setting comes from our <machine>.conf. eg:
> for beaglebone:
> ./meta-yocto-bsp/conf/machine/beaglebone-yocto.conf:
> SERIAL_CONSOLE = "115200 ttyO0"
>
> This gets processed in bitbake.conf:
> SERIAL_CONSOLES ??= "${@d.getVar('SERIAL_CONSOLE').replace(' ', ';')}"
>
> later, based on the init manager:
> busybox, systemd-serialgetty, or sysvinit-inittab use it.
>
> In this case, updating the "<machine>.conf" should help.
>
>> Thanks in advance, all the Best,
>> Jakob
>>
>> -- 
>> Jakob Hasse
>> Software Developement
>>
>> E: jakob.hasse@smart-home-technology.ch
>> T: +41 44 552 02 66
>>
>> Smart Home Technology GmbH
>> www.smart-home-technology.ch
> Best Regards,
> Maxin

-- 
Jakob Hasse
Software Developement

E: jakob.hasse@smart-home-technology.ch
T: +41 44 552 02 66

Smart Home Technology GmbH
www.smart-home-technology.ch