1. Execute `sudo fdisk -l`, the result is `/dev/mmcblk1p1`.

2. Execute `sudo mkfs.ext4 /dev/mmcblk1p1`.

3. Create the mount point `/mnt/sda1`.

4. Edit the `/etc/fstab` file using `vi`, adding the following line to the end: `/dev/mmcblk1p1 /mnt/sda1 ext4 defaults,nofail,x-systemd.device-timeout=10s 0 0`

5. Use `cat /etc/fstab` to check if the addition was successful.

6. Use `df -h | grep sda1` to check.