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.

Friday, February 23, 2018

Restore MySQL database from dump file

When restoring a MySQL db from a .sql file (such as an SQL dump file created by mysqldump), the login credentials on the target (including root) may be overwritten by the source .sql file if the .sql file was created with the --all-databases option.

RabbitMQ TLS

After copying the ca cert and key files, specify their locations in RabbitMQ's config file (/etc/rabbitmq/rabbitmq.config). Make sure the user "rabbitmq" can read them, especially the key file. Otherwise TLS connection attempts would just get stuck with no error message showing up in server nor client.