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8GB eMMC flash?

jafoste4

Hello Everyone,

If there is an 8GB eMMC flash device on the MiniZed, why when I use the df command in PetaLinux does it only show 123M available?

Thanks,

Josh

Parents
  • 0

    On your MiniZed device, is there no file /usr/local/bin/format_emmc.sh ?  If you are running a device from the factory or if you generated your running image from a published MiniZed BSP, it should be there.  In the 2017.4 and 2018.2 BSP, the user scripts are stored under project-spec/meta-user/recipes-bsp/minized-misc/

    Here is the file contentsfor the file (it only formats a 128MB partition):

    #Delete partition and add a new one of 128MB
    echo "fdisk /dev/mmcblk1 (1 partition of 128MB)"
    echo -e "d
    o
    n
    p
    1
    1
    +128M
    w
    " | fdisk /dev/mmcblk1
     
    echo "sleep 1"
    sleep 1
     
    #Format as a DOS partition
    echo "mkdosfs -F 32 /dev/mmcblk1p1"
    mkdosfs -F 32 /dev/mmcblk1p1
     
    echo "sleep 1"
    sleep 1
     
    #Mount eMMC
    echo "/dev/mmcblk1p1 /mnt"
    mount /dev/mmcblk1p1 /mnt
    echo "ls -l /mnt"
    ls -l /mnt
     
    #Unmount drive again:
    echo "umount /mnt"
    umount /mnt
     
    Stefan
  • 0 in reply to stefanrousseau

    Stefan

                 Just a dumb clarification on the above  procedure for my lack of experience on fdisk etc. You mention that once you delete a partition and add a new one, it has be to power cycled to make the new partition visible.

     

    But in the format_emmc script procedure that you pasted above, you delete the 128MB, added a new one of the same size

    and simultaneously did a Fat32 format after a sleep/halt procedure in the same code.

     

    Does the power cycling apply only to extended partitions (and not the primary) so that it is visible in the next boot.

     

    I want to make the primary as 2GB (for FAT-32) to allow sufficient capacity. (like the 512M) that you have shown.

     

    Thanks

     

    Siva R

  • 0 in reply to rsiva

    Siva,

     

    The way I remember this, the very first time you format the flash, a power cycle is not required, so the script above will work.  But subsequent attempts that need a different partition size (not just formatting) will need a power cycle.

     

    Stefan

  • 0 in reply to stefanrousseau

    Stefan

                  I will try to modify you script to make it larger (like 512M or 2048M) and see what happens with 1 partition only.

     

    Thanks

     

    Siva R

Reply Children
  • 0 in reply to rsiva

    All,

             I was able to add 2 primary partitions of 2GB each. After fdisk command is executed, you need to power cycle, then do an mkdos format for FAT 32, reboot and in the 3rd cycle, the partitions show up. // This was the BKM I adopted after going through a few iterations and also covered by Stefan earlier.

     

    I was not successful in adding an extended partition. Fdisk is not the problem, but mkdos complains "image is too small" and fails.

    Also I read somewhere that it is best to exhaust the 4 primary partitions before going to extended

    It also nicely divides the 8GB space into  4 identical partitions that allows F 32 and the useable capacity of 2GB

     

    For now I created 2 primary partitions of 2 GB each in my minized.

     

    The mount command I used for second partition is manual Since it not in the original image.

     

    mount /dev/mmcblk1p2 /p2

     

    image

    Note that initially when you delete the primary (and only partition) (of 128MB from factory) and add the 2048MB partition as primary in my example and commit the partition table, it will not be visible immediately after the fdisk command is executed. Secondly the image.ub stored in the erstwhile partition will be blown away as a side effect.

    I used the fdisk /dev/mmcblk1 and then into the prompt window to go through the configuration albeit a script can be used.

     

    On reboot, it will complain that  image.ub is not seen. make sure you have the fallback or smallboot.bin already set up. Run
    from the Zynq promt > run boot_qspi   // Follow the restoring guide for factory settings if you need more details

     

    image

    You will get back the 2017.4 peta Linux for example assuming that is your backup image.

     

    % mkdosfs -F 32 -I /dev/mmcblk1p1

    % mkdosfs -F 32 -I /dev/mmcblk1p2  // If you have created the 2nd partition)

     

    image

     

    Either you can add attach USB stick and copy the image.ub, smallboot.bin and the wpa_supplicant files (as discussed in the restoration pdf) to the emmc (p1) mounted as /mnt/emmc

     

    or in my case, I edited the default wpa* file (located in /usr/local/bin) to program my router/WIFI data, ran wifi.sh and used WinSCP to move the above image* files from windows10 to the emmc p1

     

    Plugging the USB stick and adding auxillary power and pulling them out each time is a pain (for me atleast). Connectors and sockets could become loose, touching some pins inadvertently etc can cause ESD and brick the part (theoretically).

     

    Reboot and off you go with the minized from the image.ub file in p1.

     

    Thanks

     

    Siva R