Part 7 - Create & test a PetaLinux application that runs automatically at startup

This tutorial details the steps required to build an application into PetaLinux that will run at boot time.

The aims of this tutorial are as follows :-

Setup Xilinx design environment for the 2021.2 toolset.

steve@Desktop:~$ xilinx
Xilinx tools available tools at /opt/Xilinx :-
1) 2021.2 - Vivado - SDK - Vitis - PetaLinux
0) Exit
Please select tools required or exit : 1

Tools are as follows :-
vivado @ /opt/Xilinx/Vivado/2021.2/bin/vivado
vitis @ /opt/Xilinx/Vitis/2021.2/bin/vitis
petalinux-build @ /opt/Xilinx/PetaLinux/2021.2/tool/tools/common/petalinux/bin/petalinux-build

Change the present working directory to be the project directory.

steve@Desktop:~$ cd ~/projects/zedboard_linux/os/petalinux

Create a blank application component (auto enabled).

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-create --type apps --template install --name led-runner --enable
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ cd ../..

Change the default source code to do something a little more obvious.

steve@Desktop:~/projects/zedboard_linux$ subl os/petalinux/project-spec/meta-user/recipes-apps/led-runner/files/led-runner

led-runner

#!/bin/sh

poke 0x41200000 0x18
usleep 125000
poke 0x41200000 0x3C
usleep 125000
poke 0x41200000 0x7E
usleep 125000
poke 0x41200000 0xFF
usleep 125000
poke 0x41200000 0x7E
usleep 125000
poke 0x41200000 0x3C
usleep 125000
poke 0x41200000 0x18
usleep 125000
poke 0x41200000 0x00

Direct download available here :-

steve@Desktop:~/projects/zedboard_linux$ wget https://spacewire.co.uk/tutorial/shared/repos/0007/zedboard_linux/os/petalinux/project-spec/meta-user/recipes-apps/led-runner/files/led-runner -O os/petalinux/project-spec/meta-user/recipes-apps/led-runner/files/led-runner

Change the BitBake receipe to make it suitable for an auto-start application.

steve@Desktop:~/projects/zedboard_linux$ subl os/petalinux/project-spec/meta-user/recipes-apps/led-runner/led-runner.bb

led-runner.bb

#
# This file is the led-runner recipe.
#
SUMMARY = "Simple led-runner application"
SECTION = "PETALINUX/apps"
LICENSE = "MIT"
LIC_FILES_CHKSUM ="file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

SRC_URI = "file://led-runner"

S = "${WORKDIR}"

FILESEXTRAPATHS_prepend := "${THISDIR}/files:"

inherit update-rc.d

INITSCRIPT_NAME = "led-runner"
INITSCRIPT_PARAMS = "start 99 S ."

do_install() {
  install -d ${D}${sysconfdir}/init.d
  install -m 0755 ${S}/led-runner ${D}${sysconfdir}/init.d/led-runner
}
FILES_${PN} += "${sysconfdir}/*"

Direct download available here :-

steve@Desktop:~/projects/zedboard_linux$ wget https://spacewire.co.uk/tutorial/shared/repos/0007/zedboard_linux/os/petalinux/project-spec/meta-user/recipes-apps/led-runner/led-runner.bb -O os/petalinux/project-spec/meta-user/recipes-apps/led-runner/led-runner.bb

Rebuild the project to include the updated files.

steve@Desktop:~/projects/zedboard_linux$ cd os/petalinux
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-build

Package up the project ready for deployment.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-package --prebuilt --force

If not already, connect up the hardware as follows :-

Xubuntu PC USB ⇄ Zedboard USB JTAG/Debug
Xubuntu PC USB ⇄ Zedboard USB UART
Zedboard Ethernet ⇄ Router
Xubuntu PC Ethenet ⇄ Router
Router ⇄ Internet

Set the boot mode jumpers on the Zedboard for JTAG. Missing Image!

Power on the Zedboard.

If not already running, open up a new terminal and launch the MiniCom terminal emulator.

steve@Desktop:~$ minized

Welcome to minicom 2.7.1

OPTIONS: I18n
Compiled on Dec 23 2019, 02:06:26.
Port /dev/ttyACM0, 06:34:25

Press CTRL-A Z for help on special keys

Power cycle the Zedboard and deploy the project via JTAG.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-boot --jtag --prebuilt 3

The following sequence of events should be observed.

The blue done LED illuminates indicating the Programmable Logic (PL) has been programmed.
The two middle LED's illuminate indicating the bitstream from the zedboard_leds_switches project is in use.
The software runs on the Processor System (PS).
PetaLinux starts to boot.
The led-runner application launches and executes the expanding & contracting LED illumination sequence.
The PetaLinux login prompt appears in the terminal emulator.

Add and commit the new & updated files, create an annotated tag and push the commit & tag up to the remote repository.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git add project-spec/meta-user/recipes-apps/led-runner
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git commit -a -m "Added & enabled LED runner auto-start application."
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git push
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git tag -a v3.0 -m "PetaLinux, Peek/Poke & LED Runner with XSA from zedboard_leds_switches v1.0"
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git push origin v3.0

The source files relating to this tutorial for the OS can be obtained from Bitbucket. The OS repository contains both PetaLinux and a local copy of the exported hardware (firmware).

The instructions below assume that Part 1 - Installation of tools, setup of environment and creation of project area has been completed in full and that the environment has been setup as per 1. Setup environment. The root project area ~/projects should be present and contain the common project. The zedboard_linux projects should NOT be present. Adjust the commands below to suit if the above differs.

Obtain OS source, build & deploy on Zedboard.

steve@Desktop:~$ cd ~/projects
steve@Desktop:~/projects$ git clone -b v3.0 https://bitbucket.org/spacewire_firmware/zedboard_linux
steve@Desktop:~/projects$ cd zedboard_linux/os/petalinux

Do something with the OS (if required) then perform the following steps :-

Build PetaLinux
Package PetaLinux
Setup Zedboard hardware
Launch MiniCom terminal emulator
Run PetaLinux on Zedboard via JTAG
Check everything is working as expected

Introduction

Aims

Part 1 - Project Setup

Part 2 - Create auto-run application

Part 3 - Build & package PetaLinux

Part 4 - Hardware Deployment

Part 6 - Revision Control

Part 5 - Quickstart

1. Setup environment

2. Change present working directory

3. Create auto-run application

led-runner

led-runner.bb

4. Build PetaLinux

5. Package PetaLinux

6. Setup Zedboard hardware

7. Launch MiniCom terminal emulator

8. Run PetaLinux on Zedboard via JTAG

9. Check everything is working as expected

10. Commit to repository

11. Obtain tutorial files from Bitbucket, create & build project, deploy on Zedboard