[Buildroot] how to add UART1,2,3 on beaglebone

[Buildroot] how to add UART1,2,3 on beaglebone

[Jehun Lee]

I made and load successfully on my beaglebone black by following docs on 
https://buildroot.org/docs.html.
But that image has only one ttyO0 for console. I want to add UART1,2,3 
of beaglebone black.
How can I do that? Any advice?
Thanks in advance.

yodazhong
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[Buildroot] how to add UART1,2,3 on beaglebone

[Baruch Siach]

Hi Jehun Lee,

On Tue, Jul 19, 2016 at 09:07:26PM -0700, Jehun Lee wrote:
> I made and load successfully on my beaglebone black by following docs on
> https://buildroot.org/docs.html.
> But that image has only one ttyO0 for console. I want to add UART1,2,3 of
> beaglebone black.
> How can I do that? Any advice?

You need to add getty entries in your target /etc/inittab file. Look for 
'ttyO0' in /etc/inittab, and add similar entries for ttyO{1,2,3}.

This assumes that you are using either Busybox init (most likely) or sysvinit. 
If you use systemd, add a symlink in /etc/systemd/system/getty.target.wants/ 
for each console.

Hope this helps,
baruch

-- 
     http://baruch.siach.name/blog/                  ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -

[Buildroot] how to add UART1,2,3 on beaglebone

[Lothar Felten]

Hi Jehun,

On 20.07.2016 07:20, Baruch Siach wrote:
> Hi Jehun Lee,
>
> On Tue, Jul 19, 2016 at 09:07:26PM -0700, Jehun Lee wrote:
>> I made and load successfully on my beaglebone black by following docs on
>> https://buildroot.org/docs.html.
>> But that image has only one ttyO0 for console. I want to add UART1,2,3 of
>> beaglebone black.
>> How can I do that? Any advice?
>
> You need to add getty entries in your target /etc/inittab file. Look for
> 'ttyO0' in /etc/inittab, and add similar entries for ttyO{1,2,3}.
>
> This assumes that you are using either Busybox init (most likely) or sysvinit.
> If you use systemd, add a symlink in /etc/systemd/system/getty.target.wants/
> for each console.
>
> Hope this helps,
> baruch
>

Maybe your device tree also needs an entry to enable the other uarts, 
something like this:

&uart1 {
	pinctrl-names = "default";
	pinctrl-0 = <&uart1_pins_default>;
	status = "okay";
};

(And check the pinmux, here it's the uart1_pins_default entry)

--
Lothar