Sunday, June 3, 2018

Enabling UART on the Beaglebone Black

To enable the UARTs with the recent console Debian image for the Beaglebone Black, add these lines to sudo nano /boot/uEnv.txt

uboot_overlay_addr0=/lib/firmware/BB-UART1-00A0.dtbo
uboot_overlay_addr1=/lib/firmware/BB-UART2-00A0.dtbo
uboot_overlay_addr2=/lib/firmware/BB-UART4-00A0.dtbo
uboot_overlay_addr3=/lib/firmware/BB-UART5-00A0.dtbo
disable_uboot_overlay_video=1
disable_uboot_overlay_audio=1
enable_uboot_cape_universal=1
Also run this if you're running the bone off an SD card, AND the eMMC does not have an up-to-date uboot.
sudo dd if=/dev/zero of=/dev/mmcblk1 count=1 seek=1 bs=128k
It seems that some recent changes to uboot have made these obsolete:
cape_disable=bone_capemgr.disable_partno=... cape_enable=bone_capemgr.enable_partno=...
They used to work before 4.4.x came about. Just bits and pieces gathered from forums plus a lot of trial and error.