Console output garbled?

All of a sudden, I'm getting garbled console output. Not always, but frequently.

This is a "fresh" BBB that I got a while back but haven't used. After I fried my other BBB, I moved everything over to this one, but didn't flash the eMMC.

If I boot without an SD card, it's garbled.

If I boot with an SD card but don't hold down the button, it boots from the eMMC and things are garbled.

If I boot with an SD card that has (my non-flasher Debian image) and hold the button, it boots correctly.

If I boot with an SD card that has the 10/9 console flasher image) and hold the button, it boots correctly. Then I let go of the button and it started spewing garbage (did I let go to soon? The flasher was executing; I could see the cyclon pattern):

Running uenvcmd ...
1163 bytes read in 41 ms (27.3 KiB/s)
debug: [/boot/vmlinuz-4.1.10-ti-r21] ...
8280456 bytes read in 487 ms (16.2 MiB/s)
debug: [/boot/initrd.img-4.1.10-ti-r21] ...
3948009 bytes read in 247 ms (15.2 MiB/s)
debug: [/boot/dv�����={�����o����oac����}���/ etc etc etc

The flash seems to have succeeded and now all is well, but I'd like to understand what mode it got itself into.

Also, I'm not precisely sure where in the boot process it checks for the button. Now that it's flashed, it will boot from the SD card first without me holding the button. Before, it wouldn't (I had to hold the button).


By any chance are you using “Teraterm” ?
If so, switch to Putty, and your problem will go away.

— Graham

No, I'm using screen on OS X.

Do you have the option to lock it in the basic ASCII 7 bit character set?

That would likely solve the problem.

The problem with Teraterm is that the BBB will sometimes put out some gibberish or perhaps some non-printing control characters at the start of the console output (don’t know why) and it will intermittently kick Teraterm into alternate Japanese character set. Putty only prints ASCII, so no problems.

— Graham

Interesting. My terminal windows support UTF-8, but maybe screen is doing something.