SAMA7G54-EK – Configure and Build at91bootstrap to Load an MPLAB® Harmony v3 Application from NOR Flash (QSPI) Memory

Last modified by Microchip on 2024/06/24 06:29


This training topic describes how to download, configure, and build at91bootstrap to load an MPLAB® Harmony v3 Software Framework application binary image (harmony.bin) from NOR Flash (QSPI) Memory to DDR3L SDRAM on the SAMA7G54-EK Evaluation Kit using the MPLAB X Integrated Development Environment (IDE).  

Once at91bootstrap has been built, the resulting binary image (boot.bin) can be written to NOR Flash (QSPI) memory using the SAM-BA® In-System Programmer (ISP).  

at91bootstrap is a second-stage bootloader for Microchip Technology, Arm®-based microprocessors (MPU). For more information, see the "at91bootstrap: A Second Stage Bootloader for Microchip Microprocessors" page.


​This training topic was developed with MPLAB X IDE v6.15 and XC32 v4.30.

Before You Begin

Before you begin configuring at91bootstrap, you will need some information from the production build of the MPLAB Harmony v3 application. In this example, we use harmony.bin as our application image from the "SAMA7G54-EK – Getting Started with MPLAB® Harmony 3 Development: CSP Application: pio_led_on_off_interrupt" training topic.

  1. NOR Flash Memory offset value to read harmony.bin
  2. The harmony.bin image size
  3. The DDR3L SDRAM address to load harmony.bin

These values will be used to configure at91bootstrap in the following steps.

Back to Top

NOR Flash (QSPI) Memory

The SAMA7G54-EK has a 1 Gb octal interface serial NOR Flash memory (U9) (Macronix MX66LM1G45G) configured as 8 bits x 128 MB. It is connected to the Quad Serial Peripheral Interface port 0 (QSPI0) of the SAMA7G54. 

Back to Top

Download at91bootstrap

Create a Project Directory

For the purposes of this training topic, we’ll name our project directory at91bootstrap. 

Download or clone at91bootstrap version 4 

Download or clone from the Linux4sam GitHub repository.

This training topic was developed with at91bootstrap version 4.0.6 

Back to Top

Open Project at91bootstrap

From MPLAB X IDE, select File > Open Project… 

An Open Project dialog is displayed.

Find and select the at91bootstrap project directory.

Click on the Open Project button.  

The at91bootstrap project will be displayed in the Projects pane (upper left) and the at91bootstrap – Dashboard pane (bottom left). 

Open Project

You may receive a Configuration Loading Error. This is due to an older version of the Device Family Pack (DFP) at the time of creating the at91bootstrap project. You will update the DFP to the latest version in the next steps. 

Back to Top

Configure at91bootstrap Project Properties

Open at91bootstrap Project Properties 

Open the at91bootstrap Project Properties using one of the following methods: 

  1. In the Projects pane, highlight at91bootstrap and click on the wrench icon in the at91bootstrap - Dashboard
  2. In the Projects pane, right-click on at91bootstrap and select Properties from the menu. 

The Projects Properties – at91bootstrap dialog box opens. 

If you received a Configuration Loading Error in the previous step, you may see a [Resolve] link next to a version of the Device Family Pack (DFP). Highlight the latest DFP and click on the Apply button. This will update the configuration to the latest DFP.  

Project Properties: Conf default

DFP: The DFP contains device-specific support software. The 32-bit MCU and MPU DFPs are maintained by Microchip Technology and are available on GitHub. 

Ensure the Device selected is the SAMA7G54.

Configure the XC32 Compiler

In the Categories pane, select Makefile

Enter the following text in the Build command and Debug build command boxes: 

make CROSS_COMPILE="C:/Program Files/Microchip/xc32/v4.30/bin/bin/pic32c-" 

Enter the following text in the Clean command box: 

make mplabclean CROSS_COMPILE="C:/Program Files/Microchip/xc32/v4.30/bin/bin/pic32c-" 

Type the version number of the XC32 compiler on your host computer. In this step, we are using version 4.30. 

The installation location of the XC compiler versions can be found by selecting from the MPLAB X IDE toolbar: Tools > Options. An Options dialog box will open. Select Embedded from the toolbar and select the Build Tools tab. 

When cutting and pasting, beware of hidden formatting characters. 

Project Properties: makefile

Click on the Apply button.

Configure at91bootstrap to load harmony.bin from NOR Flash (QSPI) Memory
In the Categories pane, select Kconfig and click on the Load button. 

Find the at91boostrap project directory and select the configs directory and then select sama7g5ekdf_qspi_uboot_defconfig and click on the Open button. 

Project Properties: kconfig

Make the following changes: 

In this step, you are taking an existing default configuration and altering it to load the MPLAB Harmony v3 application (harmony.bin) from NOR Flash (QSPI) memory. This makes configuration a little bit easier than starting from scratch. 

Expand Next Software Type and select the Load 4 MB into start of SDRAM radio button.

Next Software Type

Expand Demo Application Image Storage Setup

Set Flash Offset for Demo-App to 0x200000  

This is the NOR Flash (QSPI) memory offset value to the application binary (here called Demo-App). This value is planned by the developer as part of the memory map of the NOR Flash (QSPI) memory.  

Take note of this value as you will use it when writing the application binary (harmony.bin) to NOR Flash (QSPI) memory using the SAM-BA Host Applet qspiflash (see What’s Next? section below) 

Set Demo-App Image Size to 0x400000  

This is the image size of the application binary image (here called Demo-App) to be copied from NOR Flash (QSPI) to SDRAM memory by at91bootstrap.  

It is important that the Demo-App Image Size is greater than the application binary size. In this example, harmony.bin is approximately 3KB. Much smaller than the value set in the default configuration. 

Enter the address to load the application 0x66f00000 to The External Ram Address to Load Demo-App Image.  

This value should match the .text load address in the applications linker script (ddram.ld). This value is shown in the accompnyig image for the pio_led_on_off_interrupt application. 

Linker for Production: ddram

Click on the Apply and OK buttons.

 This completes the configuration of the at91bootstrap project properties. 

Back to Top

Build at91bootstrap

Build at91bootstrap 

Build the at91bootstrap project using one of the following methods: 

  1. In the Projects pane, right-click on at91bootstrap and select Build from the menu 
  2. Click on the Build icon (hammer) in the tool ribbon. 

Observe the build is successful

Build Successful

Note the location of boot.bin: 


The boot.bin file is the binary image of at91bootstrap. The boot.bin image can be written to NOR Flash (QSPI) memory using the SAM-BA Host Applet qspiflash. Instructions on how to do this are listed in the What’s Next? section below. 

Back to Top


The at91bootstrap has been configured and built to load an MPLAB Harmony v3 Software Framework application from NOR Flash (QSPI) Memory on the SAMA7G54-EK. 

Back to Top

What's Next?

Back to Top