I was able to mount the card without knowing the type, apparently mount is
smart enough to determine on its own. Does this mean that despite this
capability, each /etc/fstab entry requires full type&option specification?
Yet, you specified the partition number.
/uEnv.txt is just for backwards compatibility with older eMMC images.
This confused me (the image on the SD card is a new version, how can
backwards compatibility be needed?) Not arguing, as you certainly are
correct. Can a system running an older version from eMMC be used to boot
from the SD card, requiring a read of the older format uEnv.txt? I'm just
grasping for an explanation with this.
Well, the am335x bootrom reads the eMMC first on poweron. Thus for
older versions of U-Boot in eMMC, the backwards compatibility is
needed.
> 3) If I understand correctly there is another FAT volume on the eMMC as
> shipped, that is seen as a remote (FAT?) volume when the BBB is
> connected as
> a USB client. Is there any way to mount that for access from the bone
> directly?
It's a raw image file, /var/local/*.img
Thanks for this (partial) answer (not sarcasm here). It required that I do
some research to fully understand your response, so I learned even more. I
had assumed it was a separate partition on the SD card, exposed by the USB
client.
It use to be it's own partition, but this led to other user issues, so
it was moved to an *.img file. That file is also maintained by an apt
package, so updates can be pushed.
Now I see that there is only one partition on the SD card, and these
"file systems" presented by the USB interface are just image files, which
themselves can be mounted (if you know the magic, i.e. starting sector). I
never tried to modify this content when accessed through USB - I didn't
realize it is read-only. (please correct me if any of this is wrong)
or just use losetup/kpartk:
#find free loop device
sudo losetup -f
/dev/loop0
sudo losetup /dev/loop0 beaglebone-getting-started-2017-01-25.img
sudo kpartx -av /dev/loop0
sudo mkdir disk
sudo mount /dev/mapper/loop0p1 disk/
cd disk/
ls -lh
total 90K
drwxr-xr-x 2 root root 2.0K Feb 14 15:50 App
-rwxr-xr-x 1 root root 288 Feb 14 15:50 autorun.inf
drwxr-xr-x 4 root root 2.0K Feb 14 15:50 Docs
drwxr-xr-x 5 root root 2.0K Feb 14 15:50 Drivers
-rwxr-xr-x 1 root root 41K Feb 14 15:50 LICENSE.txt
-rwxr-xr-x 1 root root 17K Feb 14 15:50 README.htm
-rwxr-xr-x 1 root root 428 Feb 14 15:50 README.md
drwxr-xr-x 2 root root 2.0K Feb 14 15:50 scripts
-rwxr-xr-x 1 root root 17K Feb 14 15:50 START.htm
Regards,