UART2 verification on LX2160ardb Rev2.0

[hittzt]

Hi experts,

On Lx2160ardb Rev2.0 board, there are two UART ports on the front panel named UART1 and UART2, 

and stdout uses UART1 by default. 

And I want to know how to verify the UART2.

Thanks,

Zhantao

[yipingwang]

Hello Zhantao,

You could specify Linux Kernel bootargs as "console=ttyAMA1,115200" to boot up Linux Kernel from UART2.

Thanks,

Yiping

[hittzt]

Hi Yiping,

Glad to recieve your reply.

I have test what you suggested, but UART2 can not show anything, like the following:

=> env edit bootargs
edit: console=ttyAMA1,115200 earlycon=pl011,mmio32,0x21d0000 root=/dev/mmcblk0p2 rw no_console_suspend ip=dhcp crashkernel=512M selinux=0 enforcing=0
=> env save
Saving Environment to SPI Flash... Erasing SPI flash...Writing to SPI flash...done
OK
=> boot
SF: Detected mt35xu512aba with page size 256 Bytes, erase size 128 KiB, total 64 MiB
device 0 offset 0x6c0000, size 0x40000
SF: 262144 bytes @ 0x6c0000 Read: OK
device 0 offset 0xd00000, size 0x100000
SF: 1048576 bytes @ 0xd00000 Read: OK
18008576 bytes read in 889 ms (19.3 MiB/s)
32500 bytes read in 21 ms (1.5 MiB/s)
## Flattened Device Tree blob at 90000000
Booting using the fdt blob at 0x90000000
Loading Device Tree to 000000009fff5000, end 000000009ffffef3 ... OK
fsl-mc: Deploying data path layout ... SUCCESS

Starting kernel ...

After Starting Kernel ... statement, there is nothing comes out for UART2.

Thanks

[yipingwang]

(1)Linux boot log comes on UART1 console
(2)On linux prompt,Type following command to switch UART2 console
sh -c "getty 115200 /dev/ttyAMA1;true"

(3)Following prompt on UART2 console
QorIQ SDK (FSL Reference Distro) 2.4.2 lx2160ardb /dev/ttyAMA1
lx2160ardb login: root
Last login: Thu May 31 08:40:06 UTC 2018 on ttyAMA0
root@lx2160ardb:~#

[hittzt]

Thanks Yiping.

I just test the steps you give.

1. boot the board on UART1,

2. in Linux prompt, type the following command:

   sh -c "getty 115200 /dev/ttyAMA1;true"

but there is nothing in console neither on UART1 nor UART2

   root@nxp-lx2xxx:~# sh -c "getty 115200 /dev/ttyAMA1;true"

The steps above are right?

Thanks,

Zhantao

[yipingwang]

Please modify Linux Kernel dts file as the following.

chosen {
stdout-path = "serial0:115200n8";
};

=>

chosen {
stdout-path = "serial1:115200n8";
};

[hittzt]

Hi Yiping,

Thanks for your reply.

You mean set the lx2160ardb board dts to be like the following in fsl-lx2160a-rdb.dts?

aliases {
 crypto = &crypto;
 serial0 = &uart0;
 };

=>

aliases {
 crypto = &crypto;
 serial0 = &uart1;
 };

I tested that, but still failed.

Thanks,

Zhantao

[yipingwang]

After modifying the dts file as mentioned above.

Please configure bootargs as the following "console=ttyAMA1,115200 earlycon=pl011,mmio32,0x21d0000".

[hittzt]

Hi Yiping,

I will try again as you suggested.

Thanks,

Zhantao