Table of Contents

Introduction

The default XSDK debug configuration for Linux applications copies the elf file to the target before running it. It is desirable to be able to debug an application that was launched outside XSDK (e.g. at system startup). This is not shown in the default debug templates but can be done manually, as shown here. A working knowledge of XSDK is assumed, as well as familiarity with the ZCU102 board.

Test environment

You may be able to use a different test setup, so long as the following principles are preserved:

The laptop can, via Ethernet, access the ZCU102
The application being debugged has its source code available on the laptop
If the application was not developed in XSDK or was developed on a different machine, you may need path mappings to locate the sources

SD Card

Use an SD card that was supplied with, or is compatible with, the ZCU102.

Cables

USB-to-miniUSB cable supplied with the ZCU102
Two Ethernet cables (RJ45)
Power cable for ZCU102

Router

It establishes a private Ethernet network containing the laptop and the ZCU102. Ensure the router is enabled as a DHCP server and powered on, with two spare RJ45 ports. This test uses up three IP addresses – one for the laptop, one for u-boot and one for Linux on the ZCU102. Ensure the router can serve these three clients. Reboot it if necessary.

ZCU102 hardware configuration

Rev 1.1 board
Boot mode is SD card

Laptop configuration

Hardware

SD card reader
Spare USB port
Spare Ethernet port configured for DHCP slave

Software

Windows 7
XSDK 2018.2
ZCU102 2018.2 release image
CP210x USB to UART Bridge VCP Drivers

Connect Cables

USB-UART cable between ZCU102 and laptop
Ethernet cable between ZCU102 and router
Ethernet cable between laptop and router
ZCU102 power cable (leave powered down)

Insert SD Card In Card Reader

Ensure the SD card is writeable.

Locate COM port

Open 'Device Manager' via Windows -> Control Panel, and open the 'Ports (COM & LPT)' section
The line that reads 'Interface 0' has the COM port number (in this case, COM46):

It is possible that you may need to power up the ZCU102 for this information to be visible. If so, power it down after obtaining the above information.

Prepare SD Card Image

Copy ZCU102 2018.2 release image, uncompressed, to SD card
Launch XSDK
Select a workspace location
Create a Linux application 'hello' using the 'Hello world' template.
Change the code to add a forever loop:

Modified hello_world

#include <stdio.h>
#include <unistd.h>

int main()
{
    for(;;) {
        sleep(10);
        printf("Hello World\n");
    }
    return 0;
}

Ensure the active Build Configuration is set to 'Debug'
Build the application
Copy the application 'Debug\hello.elf' to the SD card
Safely eject the SD card from the laptop
Leave XSDK running

Launch Application

Insert the SD card in the ZCU102 SD card slot
Open an XSDK terminal for the COM port:

You should see 'Connected to COM46 at 115200' if it succeeds.
Apply power to the ZCU102.
You should see boot messages from Linux. Wait for the prompt: xilinx-zcu102-2018_2 login:
Login with user root and password root.
Run this command: ifconfig eth0
- Note the value of 'inet addr'
Mount the SD card to a known path: mount /dev/mmcblk

Xilinx Wiki

Debug A Running Linux App With XSDK