Unbricking the bricked BeagleBone Black Wireless was mostly painless. I needed a power source. I chose to use the USB/microUSB cable that came with it for communicating over the HOST USB port. This is the port that lets you log in via 192.168.7.2 if you are using the stock debian install.
I also needed the USB TTL serial cable, so that I could watch the console for the boot/reboot process. This wasn’t absolutely needed, but it was very useful. I highly recommend that you use one if you need to do this procedure yourself. I used “cu” to connect to the console like this:
cu -l ttyUSB0 -s 115200
The first step was to download the correct recovery image. I navigated from beagleboard.org to find it based on the board I had on hand. I started at the troubleshooting page and worked my way to the latest images link to grab the image I needed.
Once I downloaded the .img.xz file, I ran unxz to unpack it, then copied it to the microSD card via the SD card adapter:
unxz bone-debian-8.6-lxqt-4gb-armhf-2016-11-06-4gb.img.xz
sudo dd if=./bone-debian-8.6-lxqt-4gb-armhf-2016-11-06-4gb.img of=/dev/mmcblk0
Once this was done, I put the microSD card into the BeagleBone Black Wireless, hooked up the TTL serial cable, connected to it with cu, and plugged in the other USB cable to power it on. I had already booted the device while pressing the button that tells it to boot from microSD instead of eMMC, but if you are in this pickle and haven’t done that, make sure you do so now.
Over the console, I watched it boot until it gave a login prompt, and then I logged in as root (no password.) Then I checked the flashing the eMMC page to get the instructions on what file to modify, and uncommented this line in the /boot/uEnv.txt file:
cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh
A reboot from there, and the console took a while to flash the eMMC, but once it was done, everything was working again. I’ll do another write up on getting OpenBSD to work on either the wireless or the RevC in a later post.