UART4 connexion and configuration with kernel 4.1.18

Hi,

I’m currently trying to configure the UART4 of the BBB.
In addition my test is simply to connect the RX and TX pins and try to received the message through minicom.
However after my configuration I didn’t succeed to make it work. I don’t really understand why.

I use the following dtb
https://github.com/victorporof/BeagleBone-SPI-UART/blob/master/BB-UART4-00A0.dts

concerning my configuration

`
$ uname -a
Linux beagle01 4.1.18-bone20 #4 Fri Mar 18 15:16:19 CET 2016 armv7l GNU/Linux
$ lsb_release -da
Distributor ID: Debian
Description: Debian GNU/Linux 8.3 (jessie)
Release: 8.3
Codename: jessie

`

`
$ dmesg | grep tty
[ 0.000000] Kernel command line: console=ttyO0,115200n8 capemgr.enable_partno=BB-UART4 root=/dev/mmcblk0p1 ro rootfstype=ext4 rootwait
[ 0.000298] WARNING: Your ‘console=ttyO0’ has been replaced by ‘ttyS0’
[ 3.102953] 44e09000.serial: ttyS0 at MMIO 0x44e09000 (irq = 154, base_baud = 3000000) is a 8250
[ 3.903811] console [ttyS0] enabled
[ 6.705576] systemd[1]: Expecting device dev-ttyS0.device…
[ 7.174265] systemd[1]: Starting system-getty.slice.
[ 7.192955] systemd[1]: Created slice system-getty.slice.
[ 7.198476] systemd[1]: Starting system-serial\x2dgetty.slice.
[ 7.222958] systemd[1]: Created slice system-serial\x2dgetty.slice.
[ 1023.102502] 481aa000.serial: ttyS5 at MMIO 0x481aa000 (irq = 187, base_baud = 3000000) is a 8250

`

$ cat $SLOTS 0: PF---- -1 1: PF---- -1 2: PF---- -1 3: PF---- -1 4: P-O-L- 0 Override Board Name,00A0,Override Manuf,BB-UART4

`
$ ls -l /dev/ttyS*
crw------- 1 root tty 4, 64 Mar 22 10:20 /dev/ttyS0
crw-rw---- 1 root dialout 4, 65 Sep 7 2015 /dev/ttyS1
crw-rw---- 1 root dialout 4, 66 Sep 7 2015 /dev/ttyS2
crw-rw---- 1 root dialout 4, 67 Sep 7 2015 /dev/ttyS3
crw-rw---- 1 root dialout 4, 68 Sep 7 2015 /dev/ttyS4
crw-rw---- 1 root dialout 4, 69 Mar 22 09:58 /dev/ttyS5

`

`
$ cat /boot/uEnv.txt
uname_r=4.1.18-bone20
optargs=capemgr.enable_partno=BB-UART4

`

Finally I shorted the pins P9_11 and P9_13 on the board and then I launch

`
$ minicom -b 9600 -o -D /dev/ttyS5

`

Serial port setup

| A - Serial Device : /dev/ttyS5 | B - Lockfile Location : /var/lock | C - Callin Program : | D - Callout Program : | E - Bps/Par/Bits : 9600 8N1 | F - Hardware Flow Control : No | G - Software Flow Control : No

So normally I should have the answer of what I enter on the terminal (i.e an echo).
So I don’t really understand what I did wrong.
Remarque :
I don’t know if it is link but I find strange that I configure UART4 but it modifies ttyS5. However I didn’t control it,

In addition in the minicom cession it is always Offline

`
CTRL-A Z for help | 9600 8N1 | NOR | Minicom 2.7 | VT102 | Offline | ttyS5

`

If anyone have an Idea
Thanks by advance
Regards
Vincent