This post lists the commands to erase, and W95 FAT32 (LBA) format an SD card so you can boot Linux from it on a ZCU102, ZC702, or other embedded system. These instructions will fix the boot process failing as indicated by red PS_ERROR_OUT and INIT_B LEDs and the BootROM failing with the error, "0x3B - Reading failed from the selected boot device." The SD card boot switches for a ZCU102 are also listed below. To ensure you're successful.
Note: these steps will erase all the data on the SD card you use.
Step #1: Plugin your SD card
Step #2: Type dmesg to find the device name:
dmesg
At the end of the output you should see something like:
[4631534.438306] sd 33:0:0:1: [sdc] 31116288 512-byte logical blocks: (15.9 GB/14.8 GiB)
[4631534.452427] sdc: sdc1
[4631534.973011] FAT-fs (sdc1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.