SD Card

The phyCORE-AM65x SOM brings out a 4-bit wide MMC data bus to the standard SDHC card slot at X13. Power to the card slot is supplied by inserting the appropriate card into the SD/MMC1 connector, which features card detection. This interface shares a bus with the WiFi module on the SOM, but is available on the development kit as an SD card interface for external media or as a bootable interface.

Note

In order to follow this guide, you will have to boot from the on-board eMMC. Follow this guide in order to flash eMMC

Requirements

SDHC SD card, at least 8GB for PHYTEC’s TISDK release image (Included in development kit)
Linux Host PC or Virtual Machine (Ubuntu recommended) (Only for transferring media from Host)
SD card reader (operational under Linux) (Only for transferring media from Host)

Note

When an external SD Card is inserted, it will be available as /dev/mmcblk1 in Linux.

Mounting the SD card

Create a temporary directory and mount an SD card partition using the below commands:
Target (Linux)
```
mkdir /home/root/temp
mount /dev/mmcblk1p1 /home/root/temp
```

Write to the SD Card

You can use basic Linux commands to create and write files to the SD card. Below is an example:
Target (Linux)
```
echo "Hello World" > test.txt
cp test.txt /home/root/temp/
```

Read from the SD Card

To read what was just written to the SD card in the previous example, use the following command:
Target (Linux)
```
cp /home/root/test.txt read.txt
```
To check that the read file (read.txt) is the same as the one that was written (test.txt) you can use md5sum to compare and verify the data transfer was successful:
Target (Linux)
```
md5sum /home/root/test.txt && md5sum read.txt
```
The above command will generate a long and seemingly random string of characters for both files. This long string is called a “hash” and it uniquely identifies the files. If the hash for both files match then you can be confident that both files (down to each bit) are identical.
Expected Output
```
root@am65xx-phycore-kit:~# md5sum /home/root/test.txt && md5sum read.txt
e59ff97941044f85df5297e1c302d260  /home/root/test.txt
e59ff97941044f85df5297e1c302d260  read.txt
```

Unmounting the SD Card

Before unplugging the device from the development kit, make sure to unmount it in software. You can do this by running the following command:
Target (Linux)
```
umount /home/root/temp
```