K24 SoM eMMC/SD Programming with KD240 and Custom Carrier

K24 SOM bringup in KD240 Carrier Card Using K24 SoM BSP

Prerequisite:

• Vivado 2024.1
• Petalinux 2024.1
• K24C SOM BSP

Objective of the document

• Bringing up eMMC/SD interfaces for K24 Commercial Grade SoM with KD240 and Petalinux.

Overview

K24 SOM consists of QSPI and eMMC memory peripherals for running OS and applications from these memories. But at start K24 SOM comes with empty QSPI and eMMC memory. In this project we are going to boot Petalinux 2024.1 from eMMC and bootloaders from QSPI memory. For this we will be using K240 SOM BSP consisting of PS hardware design. Further we are doing K24 SOM bringup using KD240 carrier card.

For installing petalinux in eMMC, we need to boot from SD card. In other starter boards like KV260 SD card is interfaced through SD interface but in case of KD240 carrier SD card is interfaced through USB0. K24 SOM BSP base hardware design consists of minimal enabled hardware and buses. So depending upon carrier card we need to design hardware in Vivado.

1. Hardware generation in Vivado

1.1 Creating Petalinux Project

Minimal hardware is available in K24 SOM BSP, get it from following Petalinux Download link.

Next initialize petalinux and vivado toolchain and create petalinux project from the BSP and change to new petalinux project directory:

source   /Xilinx/ViVado/2024.1/settings64.sh   
source Xilinx/petalinux/2024.1/settings.sh   
petalinux-create -t project -s xilinx-k24c-som-v2024.1-05230256.bsp -n   k24-som-base-2024-1   
cd k24-som-base-2024-1

Here is the content of the just created peralinux folder:

Base hardware vivado project is located at ‘hardware’ directory as show below:

1.2 Configuring Zynq MPSoC PS block in Vivado

Open the hardware file in Vivado using GUI or running following command in terminal. For this to work one has to source the Vivado build tool environment:

source <tools>/Xilinx/Vivado/2024.1/settings.sh

Then run following command to open the hardware project:

vivado xilinx-k24c-som-2024.1.xpr

Next in Vivado project view open the hardware block design by clicking “Open Block Design” in IP INTEGRATOR tree.

It consist of Zynq Ultrascale PS block only. To configure the PS block double click on “zynq_ultra_ps_e_0” block in Diagram window:

It will open PS Ultrascale+ Block Design, which shows basic I/O peripherals enabled in the hardware project.

Here QSPI, SDO/eMMC and Display port is already enabled but need to configure according to carrier card requirement.

Further we need to boot from SD card to load petalinux image to eMMC. For this one has to enable and configure USB0 as sd-card interface is connected through USB hub IC in KD240 carrier card. Details of SD card interface IC connected to PS can be found in KD240 carrier board schematics page 18:

So first configure the USB I/O by clicking into I/O Configuration > High Speed > USB and setting values as shown below:

Next open the “Clock Configuration” and note down the Reference clock numbers. These clock numbers will be used later in the device tree of Petalinux project.

1.3 Generating XSA

After configuring the PS block. Synthesize and generate bitstream by clicking “Generate Bitstream” in Flow Navigator. This will synthesize and implement the hardware blocks and generate the bitstream.

Now next export xsa by going to File > Export > Export Hardware. Next in Export Hardware Platform option select “Include Bitstream”

After completing the Export Hardware Platform window, xsa is generated in the respective vivado project folder.

2. Petalinux build from K24 SOM BSP

Now go to Petalinux project creation folder created in Step 1.1 update the project with XSA by running following command:

petalinux-config --get-hw-description=<path to the modified XSA file   containing directory>

Next one need to update the device tree by setting attributes for the USB and Display port. For this one has to add new attributes in system-user.dtsi k24-som-base-2024-1/project-spec/meta-user/recipes-bsp/device-tree/files/system-user.dtsi

Updated system-user.dtsi is found at the download section of this hackster article.

Then run following commands to build the project and package BOOT.BIN and sd-card image.

petalinux-build   
petalinux-package --boot --u-boot --force   
petalinux-package --wic --images-dir images/linux/ --bootfiles "ramdisk.cpio.gz.u-boot,boot.scr,Image,system.dtb"

This will create BOOT.BIN and petalinux-sdimage.wic file at k24-som-base-2024-1/images/linux directory.

3. Loading Boot.bin to QSPI

QSPI memory can be loaded either using Vivado GUI or using xsct command line. Vivado GUI works fine for blank QSPI memory but once it is loaded with bootloaders it fails. But xsct tool works in both empty or memory previously loaded with BOOT.BIN file

Using xsct to load QSPI memory

Connect the carrier card containing K24 SOM through USB to serial cable and run any serial terminal application like `gtkterm` in host machine.

Run the `xsct` application present in

<petalinux_installations>/2024.1/components/xsct/bin/xsct

in host terminal.

Then run following commands to load the Boot.bin to DDR memory of K24 SoM

In xsct terminal:

source boot.tcl

This will boot u-boot in the K24 board and serial terminal stops at uboot console.

Next copy the Boot.bin to DDR memory:

dow -force -data BOOT.BIN 0x80000

After transfer is complete, exit the `xsct` terminal.

In uboot terminal in serial terminal run following commands to load the `BOOT.BIN` present in DDR to QSPI memory:

ZynqMP> sf probe 0x0 0x0 0x0    
ZynqMP> sf erase <offset address on flash> <greater than the size qspi bin>   
ZynqMP> sf write <ddr address> <offset address on flash> <greater than the   size qspi bin>

Here is the console log for above command run in the serial console:

This will copy BOOT.BIN to QSPI and ready to boot from secondary memory device.

4. Preparing SD card with eMMC linux image

First load the ‘petalinux-sdimage.wic’ into SD card by using SD card burning tool like Balena Etcher.

This will create an SD card with two partitions ‘boot’ and ‘root’.

Next compress the wic image using a compression tool like gzip in the host machine, which will decrease the image size.

gzip   -c images/linux/petalinux-sdimage.wic > petalinux-sdimage.wic.gz

Now copy the zipped file into SD cards /root/home/petalinux directory.

Now SD card is ready to load the petalinux image into K24 emmc.

5. Loading Petalinux image into K24 SOM eMMC

Now boot the SD card in the K24 SOM attached carrier card board. After successful boot one will get login prompt of Petalinux. Login using `petalinux` and set the password of your choice.

Now to load the image into eMMC run following commands in Petalinux serial terminal:

xilinx-k24c-som-20241:~$   sudo su   xilinx-k24c-som-20241:~$ gunzip -c  /boot/petalinux-sdimage_mmcblk0p2.wic.gz   | dd of=/dev/mmcblk0

After a while it will print out the following message, showing completion of eMMC writing step.

6. Booting from eMMC

Now to boot from eMMC just remove the SD card from the sd-card slot of carrier card and power on the board. This will automatically boot from eMMC memory.

Tutorial completes here!

Kudos to Sanam Shakya, our Senior Engineer for creating this in-depth tutorial for K24C SoM bringup in KD240 carrier.

This tutorial can also be followed for your custom carrier for K24. For custom carrier you will have own schematic based on that you have to select the proper PS interfaces and MIO as needed.

LogicTronix is AMD-Xilinx Partner for FPGA Design and Machine Learning Acceleration. LogicTronix is also partner for AMD-Xilinx Kria SoMs for AI/ML Acceleration.

For any queries or inquiries you can write us at : info@logictronix.com.