How do I load Ubuntu 20.04 OS to eMMC?

Dec 23, 2020 - 2:52 AM

  • Just received 3 API's. After using one for about a week and getting it configured the way I like, I accidentally disconnected power and it seems to have made the file system a brick :(

    (Edited to clarify @green's question) I decided to use this opportunity to upgrade to Ubuntu 20.04. I created 1 usb as a os and the second usb with the v20.04 img. I then booted from os usb and dd'ed the file.img (on the second usb) to eMMC raw device. When I attempt to boot I get a error message that says could not find device and then a GRUB prompt is shown.

    What do I need to do to get Ubuntu 20.04 to boot properly from the eMMC memory?

    This post was edited Dec 23, 2020 12:09PM
  • What were your dd commands?

    The part about dd to a data USB confuses me. Once you unzip it its simply a disk image file that becomes the dd if= argument.

    A common mistake is using a partition i.e. /dev/mmcblk0p1 as the dd of= target instead of the raw device /dev/mmcblk0.

    Another DLI weirdness, it appears they have the partitions on the images reversed with EFI on p2 and / on p1 Not sure how this can happen but
    sudo fdisk -l gives:

    atomicpi@AtomicPi:~$ sudo fdisk -l /dev/mmcblk0
    Disk /dev/mmcblk0: 14.58 GiB, 15636365312 bytes, 30539776 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disklabel type: dos
    Disk identifier: 0x26b43a83

    Device Boot Start End Sectors Size Id Type
    /dev/mmcblk0p1 264192 30539742 30275551 14.4G 83 Linux
    /dev/mmcblk0p2 2048 264191 262144 128M ef EFI (FAT-12/16/32)

    Partition table entries are not in disk order.

  • @green
    Thanks for the info, I tried dd to both p1 and raw device before posting the question. Current img is to raw device, thats what gives me the error and grub command line. So what is the solution?

    This post was edited Dec 23, 2020 11:52AM
  • could it be that p1 and p2 are merely names - and can start and end wherever????

  • Replaced LXDE with LXQT.
    This was easy enough. I made an SD card with Knoppix on it - the installation version which can be made that also has a Home partition. Copied the LXQT image there. The Pi boots Knoppix OK. Then used dd to copy the image to the Pi's emmc.
    Note: Knoppix installation with Home is made with a utility that is in the Live-DVD version.
    It has 2 partitions - a FAT32 EFI, and a Reiser linux. Home is on the latter, all of Knoppix on the former.