ZCU104 board

The ZCU104 board enables testing DDR4 SO-DIMM modules. It features a Zynq UltraScale+ MPSoC device consisting of PS (Processing System with quad-core ARM Cortex-A53) and PL (programmable logic).

On the ZCU104 board the Ethernet PHY is connected to PS instead of PL. For this reason it is necessary to route the Ethernet/EtherBone traffic through PC <-> PS <-> PL. To do this, a simple EtherBone server has been implemented (the source code can be found in the firmware/zcu104/etherbone/ directory).

The following instructions show how to set up the board for the first time.

Board configuration

To make the ZCU104 boot from SD card it is neccessary to ensure proper switches configuration. The mode switch (SW6) consisting of 4 switches is located near the FMC LPC Connector (J5) (the same side of the board as USB, HDMI, Ethernet). For details, see “ZCU104 Evaluation Board User Guide (UG1267)”. To use an SD card, configure the switches as follows:

  1. ON

  2. OFF

  3. OFF

  4. OFF

Preparing SD card

For easiest setup, get the pre-built SD card image zcu104.img from github releases. It has to be loaded to the microSD card. To load it to the SD card, insert the card into your PC card slot and find the device name. lsblk can be used to check available devices. Example output can look like:

$ lsblk
sda           8:0    0 931.5G  0 disk
└─sda1        8:1    0 931.5G  0 part /data
sdb           8:16   1  14.8G  0 disk
├─sdb1        8:17   1   128M  0 part /run/media/BOOT
└─sdb2        8:18   1   128M  0 part /run/media/rootfs
nvme0n1     259:0    0 476.9G  0 disk
├─nvme0n1p1 259:1    0   512M  0 part /boot
└─nvme0n1p2 259:2    0 476.4G  0 part /

In the example output the SD card is sdb with two partitions sdb1 and sdb2.


Make sure that you have selected the proper device name or you may damage the hard drive on your system! Check the device SIZE to match the size of your microSD card and compare the outputs of the lsblk command with and without the SD card inserted.

Make sure to unmount all partitions on the card before loading the image. For example, assuming the SD card is /dev/sdb (device is without a number), use sudo umount /dev/sdb1 /dev/sdb2 to unmount its partitions.

To load the image, use the following command, replacing <DEVICE> according to the output of lsblk (in the example above it would be /dev/sdb):

sudo dd status=progress oflag=sync bs=4M if=zcu104.img of=<DEVICE>

Now, the microSD card should be ready to use. If it has been loaded successfully, you should be able to mount the two partitions (BOOT and rootfs) on your PC and browse the files. First, check if your system hasn’t auto-mounted the partitions. If not, then you can for example use:

sudo mkdir -p /mnt/boot /mnt/rootfs
sudo mount /dev/sdb1 /mnt/boot
sudo mount /dev/sdb2 /mnt/rootfs

Loading bitstream

Instead of loading the bitstream through the JTAG interface, it must be copied to the microSD card BOOT partition (FAT32). The bitstream will be then loaded by the bootloader during system startup.

The prebuilt card image comes with a sample bitstream, but in order to use the provided row-hammer Python scripts, a fresh bitstream must be created. Build the bitstream as you would do for other boards:

export TARGET=zcu104
export IP_ADDRESS=...  # optional
make build


You only need to export IP_ADDRESS if you want to use a different address than the default one (see Network setup).

The resulting bitstream file will be located in build/zcu104/gateware/zcu104.bit. Copy it to the BOOT partition (FAT32) of the microSD card. Make sure it is named zcu104.bit.

When the SD card is ready, insert it into the microSD card slot on your ZCU104 board and power it on.

Verifying if bitstream is loaded

The first indication that the bitstream has been loaded successfully are the onboard LEDs. When the board is powered up, the LED will be red, which then turns green if the bitstream is loaded successfully. The ZCU104 bitstream will also make the four LEDs near the user buttons turn on and off in a circular pattern.


The board without a bitstream.


The state when the bitstream has been loaded successfully.

The serial console over USB can be used to further check of the board is working correctly.

ZCU104 microUSB

ZCU104 has a microUSB port connected to the FTDI chip. It provides 4 channels, which are connected as follows:

  • Channel A is configured to support the JTAG chain.

  • Channel B implements UART0 MIO18/19 connections.

  • Channel C implements UART1 MIO20/21 connections.

  • Channel D implements UART2 PL-side bank 28 4-wire interface.

In general they should show up as subsequent /dev/ttyUSBx devices (0-3 if no other were present). Channel B is connected to the console in the PS Linux system.

To login to the board connect the microUSB cable to the PC and find Channel B among the ttyUSB devices in your system. If there are only ttyUSB0 to ttyUSB3 than Channel B will be ttyUSB1.

Then use e.g. picocom or minicom to open the serial console. Install one of them if not already installed on your system. With picocom use the following command (may require sudo):

picocom -b 115200 /dev/ttyUSB1

Then press enter, and when you see the following prompt,

Welcome to Buildroot
buildroot login:

use login root and empty password. You can set up a password if needed.

Network setup

Connect the ZCU104 board to your local network (or directly to a PC) using an Ethernet cable.

The board uses a static IP address. By default it will be If it does not conflict with your local network configuration you can skip this section. (the default configuration can be found here).

To verify connectivity, use ping You should see data being transmitted, e.g.

$ ping
PING ( 56(84) bytes of data.
64 bytes from icmp_seq=1 ttl=64 time=0.332 ms
64 bytes from icmp_seq=2 ttl=64 time=0.072 ms
64 bytes from icmp_seq=3 ttl=64 time=0.081 ms

Modifying network configuration

If you need to modify the configuration, edit file /etc/network/interfaces. The Linux rootfs on the SD card is fairly minimal, so there is only the vi editor available. You could also just mount the card on your PC and edit the file.

After changing the configuration, reboot the board (type reboot in the serial console) and test if you can ping it with ping <NEW_IP_ADDRESS>.

SSH access

These instructions are optional but can be useful for more convenient updates of the bitstream (no need to remove the SD card from the slot on ZCU104).


SSH on the board is configured to allow passwordless root access for simplicity but if that poses a security risk, modify /etc/ssh/sshd_config according to your needs and add a password for root.

You can login over SSH using (replace the IP address if you modified board network configuration):

ssh root@

To access the boot partition, first mount it with:

mount /dev/mmcblk0p1 /boot

This can be automated by adding the following entry in /etc/fstab:

/dev/mmcblk0p1 /boot            vfat    rw              0       2

When the boot partition is mounted, you can use scp to load the new bitstream, e.g.

scp build/zcu104/gateware/zcu104.bit root@

Then use the reboot command to restart the board.

Controlling the board

When the setup has been finished the board can be controlled as any other board. Just make sure to use export TARGET=zcu104 before using the scripts (and export IP_ADDRESS=... if you modified the network configuration).