# Serial port fail with ConnectCore 6UL & Yocto with systemd

**URL:** <https://forums.digi.com/t/serial-port-fail-with-connectcore-6ul-yocto-with-systemd/21602>\
**Category:** Embedded Devices\
**Tags:** serial-interface, connectcore, embedded-linux, serial-communication, yocto\
**Created:** [July 30, 2020, 8:13am UTC](https://forums.digi.com/t/serial-port-fail-with-connectcore-6ul-yocto-with-systemd/21602 "2020-07-30T08:13:08Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![TCRobotics](https://avatars.discourse-cdn.com/v4/letter/t/9f8e36/32.png) [@TCRobotics](https://forums.digi.com/u/TCRobotics)\
**Post date:** [July 30, 2020, 8:13am UTC](https://forums.digi.com/t/serial-port-fail-with-connectcore-6ul-yocto-with-systemd/21602/1 "2020-07-30T08:13:08Z")

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I was able to read and write through serial with an C application before.

But after I change sysvinit to systemd the serial port doesn’t work anymore (ttymxc1).

The console serial port (ttymxc4) works ok.

When ttymxc1 is opened by the app, at the system console trows:

20ec000.sdma: sdma firmware not ready!  
imx-uart 21e8000.serial: Prepare for the RX slave dma failed!

Also the bluetooth init fails because seems to work only with sysvinit:

[FAILED] Failed to start Initialization of the bluetooth chip.  
See ‘systemctl status bluetooth-init.service’ for details.

Jul 30 06:21:27 ccimx6ulsbc bluetooth-init[656]: /etc/bluetooth-init: .: line 91: can’t open ‘/etc/init.d/functions’: No such file or directory

Anyone could give any clues to make the serial work again?

I need systemd to control the start and fail restart of the app.

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<div class="post-metadata">

**Author:** ![LeonidM](https://avatars.discourse-cdn.com/v4/letter/l/d26b3c/32.png) [@LeonidM](https://forums.digi.com/u/LeonidM)\
**Post date:** [July 30, 2020, 4:33pm UTC](https://forums.digi.com/t/serial-port-fail-with-connectcore-6ul-yocto-with-systemd/21602/2 "2020-07-30T16:33:23Z")

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Have you tried this with stock DEY-3.0 images?

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<div class="post-metadata">

**Author:** ![TCRobotics](https://avatars.discourse-cdn.com/v4/letter/t/9f8e36/32.png) [@TCRobotics](https://forums.digi.com/u/TCRobotics)\
**Post date:** [July 31, 2020, 2:22pm UTC](https://forums.digi.com/t/serial-port-fail-with-connectcore-6ul-yocto-with-systemd/21602/3 "2020-07-31T14:22:55Z")

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No, tried with DEY 2.6

The new release has changes in this topic??

If yes I have now an excuse to upgrade