On Tuesday, February 14, 2017 at 1:55:16 PM UTC-8, RobertCNelson wrote: > > > 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. > > Ugh. Yes, I did. Point being (point taken) that partitioning on the SD card is unknowable, so no way to auto-mount the SD card. I suppose the first partition could be auto-mounted, but that may or may not be what is desired, so best to do nothing. Sorry I missed that obvious issue...
> >> /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. > > Does that mean that it's not possible to boot a bone from SD card if there is no uboot in eMMC? Or is eMMC uboot needed to provide logic that overrides the bootrom search order, bypassing valid boot code that is found before reaching the SD card? > > >> > 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. > Clever - particularly being able to push updates. > > > 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) > > This will need more study. Thanks for the homework... :-) > 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, > > -- > Robert Nelson > https://rcn-ee.com/ > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/6520eaee-cc45-475f-8f1b-ae6909ee118a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
