[SOLVED] BBB: Using UARTs from SD card booted system

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[SOLVED] BBB: Using UARTs from SD card booted system

Postby mariusmmg2 » Fri May 20, 2016 4:10 pm

Hi,

Why the default *[0] UART enabling method doesn't work from SD card booted distro?

(It doesn't work because there's no "bone_capemgr.9" directory).

Will it work if I flash the distribution on the EMMC?

I have booted the latest image, 4.5.x Linux kernel.

*[0] By running this command: echo BB-UART1 > /sys/devices/bone_capemgr.9/slots
Last edited by mariusmmg2 on Thu May 26, 2016 6:55 am, edited 1 time in total.
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Re: BBB: Using UARTs from SD card booted system

Postby mariusmmg2 » Sun May 22, 2016 2:23 pm

Additional information: The board is Beaglebone Black rev.C, it comes with Debian pre-installed, from Debian I was able to enable and use three UARTs.

I need to run some UART speedtest with 4.5.x Linux kernel, I expect to have improved serial drivers.
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Re: BBB: Using UARTs from SD card booted system

Postby mariusmmg2 » Mon May 23, 2016 10:47 am

Update: I have installed core/linux-am33x 4.6.0-3 and core/linux-am33x-headers 4.6.0-3, same result: no /dev/ttyO* files.

I have also followed this *[0] tutorial (for rev.C), no results.

Any ideas?

*[0]: http://beaglebone.cameon.net/home/serial-ports-uart
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Re: BBB: Using UARTs from SD card booted system

Postby mariusmmg2 » Thu May 26, 2016 6:51 am

Update: It's working, the UART peripherals are now mapped to /dev/ttyS* system files.

Also, the slots file is now located in /sys/devices/platform/bone_capemgr/slots.

The automatic configuration from /boot/uEnv.txt won't work (at least with 4.6.0-3 Linux Kernel).
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