BBB Jessie image with UART4 support

Hello Robert,

I am yet reluctant to build images by myself... Having seen your rapid
jessie updates... will you provide support for UART4 any soon as
curretly it recognizes just /dev/ttyS[0-3] ?

Have to demo an application to a cient on the BBB next week and hate to
go back to 2014 wheezy for issues with Python :frowning:

TIA, Enoch.

I have my serial capes today, so i'm testing, this change:


Once i verfiy that, i'll push them out asap..


and pushed out.. should hi the repo's a few hours:

sudo apt-get update ; sudo apt-get install linux-image-3.14.35-ti-r55
; sudo reboot

Otherwise a *.deb will be available here shortly:


Thank you!

By the way, isn't an ./ supposed to do the same?

Regards, Enoch.

Robert Nelson <>

it 'should'.... (that script is just a wrapper around apt-get..)


but my builds are done..

and rsync is running... So give a it a few minutes.. :wink:


Hi Robert,

Sorry, this created /dev/ttyS4 indeed but it does not seem to work.
I also checked for echo by shorting UART4 RXD P9-11 to TXD P9-13.
                                and UART1 RXD P9-26 to TXD P9-24.

TIA, Regards, Enoch.

Robert Nelson <>

I am confused about your problem.
I am running the March 1 jessie snapshot.
I am using UART4 to talk to a GPS.
In this case, UART4 appears on ttyO4.
It works fine, and Termios is also happy.
You do have to create a custom “.dtb” using Robert Nelson’s dtb-rebuilder to
both enable the driver and remap the pin-mux, so that the UART4 is connected to
the P9-11 and P9-13.

Have you created the necessary “.dtb” ?

— Graham

You need a DTB with the UARTs enabled. See:

In particular, for ttyO4 you’ll want to look at:

The steps are:

git clone cd dtb-rebuilder git checkout 3.14-ti make src/arm/am335x-boneblack-ttyO4.dtb cp src/arm/am335x-boneblack-ttyO4.dtb /boot/dtbs/uname -r`/


Then you’ll need to edit /boot/uEnv.txt and add:



Then reboot; check dmesg to make sure that the pinmux-helper has properly set up the pins for uart mode.


If all that you want different from the default configuration is ttyO4 working, then Winston’s advice is good.

If there are other/additional changes, then you will need to make additional edits or changes to the “.dts” or “.dti” files.

— Graham

Just need someone to build it. :wink:

The best place is in the 'getting started' which is already powered by nodejs...