This guide will show how to mount, read from, and write to the phyCORE-i.MX7 onboard eMMC. In order to follow this guide your phyBOARD-i.MX7 development kit must be booting from SD Card.
Be careful with the fdisk command. You can accidentally delete the contents of other memory devices connected to the system.
Viewing available eMMC partition information
The eMMC corresponds to /dev/mmcblk2 in Linux when booting from SD Card. You can verify the eMMC partitions by using the following command:
The fdisk command line utility will output disk partition information. Search through the list and verify the eMMC is listed. You should find an entry similar to the following:
Disk /dev/mmcblk2: 3.6 GiB, 3850371072 bytes, 7520256 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: 0x243d4084 Device Boot Start End Sectors Size Id Type /dev/mmcblk2p1 4096 20479 16384 8M 83 Linux /dev/mmcblk2p2 20480 7520255 7499776 3.6G 83 LinuxCODE
Mounting the eMMC
In order to read and write to the eMMC you will need to create a directory and then mount the partition you want to read from to that directory. Follow the steps below to mount partition 1 of the eMMC:
mkdir temp && mount /dev/mmcblk2p1 temp/CODE
Check the contents of the eMMC by entering the following:
Writing to the eMMC
You can write to the eMMC by using the copy or move commands just like in Linux. To demonstrate, first create a test file.
echo "Hello World" > test.txtCODE
Now copy this file to the mounted eMMC:
cp test.txt temp/CODE
Verify that the file was written to the eMMC (test.txt should be listed in the output):