Getting Started with FRDM-IMX91 Development Board

The i.MX Linux board support package (BSP) is a collection of binary files, source code and support files that are used to boot an Embedded Linux image on a specific i.MX development platform.

Current releases of Linux binary demo files can be found on Linux download page. Additional documentation is available in the i.MX Linux documentation bundle under the Linux sections of the i.MX Software and Development Tools.

2.1 Overview

FRDM-IMX91 support booting from eMMC and SD card.

This Getting Started guide only outlines a few methods of flashing the Linux BSP image to an SD card. Experienced Linux developers can explore other options if desired.

2.2 Download an NXP Linux BSP Pre-Built Image

The latest pre-built images for the FRDM-IMX91 are available on the FRDM i.MX 91 Development Board.

The pre-built NXP Linux binary demo image provides a typical system and basic set of features for using and evaluating the processor. Without modifying the system, the users can evaluate hardware interfaces, test SoC features and run user space applications.

2.3 Burn NXP Linux BSP Image Using Universal Update Utility (UUU)

In addition to the connections from "Out of the Box" section, connect the USB1 to the host machine using the proper USB cable.

Turn off the board. Refer to the "1.5 Boot Switch Setup" section and configure the board to boot on serial download protocol (SDP) mode.

Depending on the OS used in the host machine, the way to transfer the Linux BSP image onto an SD card can vary. Choose an option below for detailed instructions:

$ chmod a+x uuu $ sudo ./uuu -b sd_all imx-image-full-imx91frdm.rootfs.wic.zst

uuu.exe -b sd_all imx-image-full-imx91frdm.rootfs.wic.zst

In the section, a brief guide of how to build Yocto BSP image for FRDM-IMX91 is introduced, along with how to add Matter support and how to build Debian release image

3.1 FRDM-IMX91 Yocto BSP

The FRDM-IMX91 BSP release is based on i.MX SW 2024 Q3 release with Yocto Project 5.0 (Scarthgap). To build FRDM-IMX91 image from source code, please first check i.MX Yocto Project User's Guide to get familiar with Yocto project and Yocto build. Then please follow below steps to build image for FRDM-IMX91.

1. Download i.MX SW 2024 Q3 BSP Release:

$ repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-scarthgap -m imx-6.6.36-2.1.0.xml 
$ repo sync 

2. Integrate meta-imx-frdm layer into Yocto code base:

   $ cd ${MY_YOCTO}/sources
   $ git clone https://github.com/nxp-imx-support/meta-imx-frdm.git

3. Yocto Project Setup:

   $ cd ${MY_YOCTO}
   $ MACHINE=imx91frdm DISTRO=fsl-imx-xwayland source sources/meta-imx-frdm/tools/imx-frdm-setup.sh -b frdm-imx91

4. Build images:

   $ bitbake imx-image-full

5. Flashing SD card image:

   $ zstdcat imx-image-full-imx91frdm.rootfs.wic.zst | sudo dd of=/dev/sdx bs=1M && sync

   Or using uuu to burn image into SD card:

   $ uuu -b sd_all imx-image-full-imx91frdm.rootfs.wic.zst

6. Change boot switch SW1[1:4] to "1100" to select SD card boot, insert the SD card and power up the FRDM-IMX91 board.

3.2 FRDM-IMX91 Matter Support

FRDM-IMX91 has support for Matter. To include Matter support, please follow below steps to include Matter layer into Yocto build.

1. Download i.MX SW 2024 Q3 BSP Release:

$ repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-scarthgap -m imx-6.6.36-2.1.0.xml
$ repo sync 

2. Download i.MX Matter Yocto layer:

   $ cd ${MY_YOCTO}/sources/meta-nxp-connectivity
   $ git remote update
   $ git checkout imx_matter_2024_q3

3. Integrate meta-imx-frdm layer into Yocto code base:

   $ cd ${MY_YOCTO}/sources
   $ git clone https://github.com/nxp-imx-support/meta-imx-frdm.git

4. Yocto Project Setup:

   $ cd ${MY_YOCTO}
   $ MACHINE=imx91frdm-iwxxx-matter DISTRO=fsl-imx-xwayland source sources/meta-imx-frdm/tools/imx-frdm-matter-setup.sh bld-xwayland-imx91

5. Build images:

$ bitbake imx-image-multimedia

3.3 FRDM-IMX91 Debian

FRDM-IMX91 has support for Debian 12 OS. i.MX Debian Linux SDK distribution is a combination of NXP-provided kernel and boot loaders with a Debian distro user-space image, which includes:

• Debian-based rootfs
  1. Debian Base (basic packages)
  2. Debian Server (more packages without GUI Desktop)
  3. Debian Desktop (with GNOME GUI Desktop)
• Linux kernel
• BSP components
• various applications (graphics, multimedia, networking, connectivity, security, and AI/ML)

For more details of NXP Debian Linux SDK Distribution, please check NXP Debian Linux SDK Distribution for i.MX and Layerscape

Quick Start with Debian

To create an SD card with Debian for FRDM-IMX91, please follow below steps.

1. Download flex-installer on the Linux host

$ wget http://www.nxp.com/lgfiles/sdk/lsdk2412/flex-installer
$ chmod +x flex-installer
$ sudo mv flex-installer /usr/bin

2. Plug the SD card into the Linux host and install the images as below

# format SD card
$ flex-installer -i pf -d /dev/sdb
# automatically download and install images into SD card
$ flex-installer -i auto -d /dev/mmcblk1 -m imx91frdm

3. Plug the SD card into the FRDM-IMX91 board and install the extra packages as below
   1. setup Ethernet network interface by DHCP or setting it manually

   $ dhclient -i end0

   2. Set correct system time, for example

   $ date -s "22 Nov 2024 09:00:00"

   3. Install extra packages for GNOME GUI Desktop version

   $ debian-post-install-pkg desktop

   4. Or install extra packages for Server version without GUI Desktop

   $ debian-post-install-pkg server

   5. After finishing the installation, run the reboot command to boot up the Debian Desktop/Server system

Building Debian Images with Flexbuild

To build Debian image with Flexbuild for FRDM-IMX91, please follow below steps.

1. Set up the build environment

   $ git clone https://github.com/nxp/flexbuild
   $ cd flexbuild && source setup.env
   #Continue to run commands below in case you need to build in Docker due to lack of Ubuntu 22.04 or Debian 12 host
   $ bld docker
   $ source setup.env

2. Build image with Flexbuild

   $ bld -m imx91frdm

3. Flexbuild usage:

   To build individual part of the image, please check below command list for Flexbuild usage

   $ bld uboot -m imx91frdm (compile u-boot image for imx91frdm)
   $ bld linux (compile linux kernel for all arm64 i.MX machines)
   $ bld bsp -m imx91frdm (generate BSP firmware)
   $ bld boot (generate boot partition tarball including kernel, dtb, modules, distro bootscript for iMX machines)
   $ bld multimedia (build multimedia components for i.MX platforms)
   $ bld rfs -r debian:server (generate Debian server rootfs)
   $ bld apps -r debian:server (compile apps against runtime dependencies of Debian server RootFS)
   $ bld merge-apps -r debian:server (merge iMX-specific apps into target Debian server RootFS)
   $ bld packrfs -r debian:server (pack and compress target debian server rootfs)

To enable faster development for users of all skill levels, NXP provides extensive example applications to showcase various features and capabilities of the platform.

4.1 Application Code Hub

The Application Code Hub (ACH) repository enables engineers to easily find microcontroller and processor software examples, code snippets, application software packs and demos developed by NXP in-house experts. This space provides a quick, easy and consistent way to find microcontroller and processor applications.

ACH provides filter and search options to quickly find specific applications. With the support of Git capabilities, there is an easy way to import and use applications within user’s development environments.

To learn more details of Application Code Hub (ACH), please visit this link.

4.2 GoPoint for i.MX Applications Processors

The GoPoint for i.MX Application Processors is a user-friendly application launches pre-built applications packed with the Linux BSP, giving users an excellent out-of-the-box experience and hands-on experience with i.MX SoC's capabilities. GoPoint highlights advanced features while providing practical solutions for implementation, with source code and build recipes for the applications provided in GitHub.

To learn more details of GoPoint, please visit this link .

Serial Communication Console Setup

The serial-to-USB drivers are available at CH342F Linux Drivers .

On the command prompt of the Linux host machine, run the following command to determine the port number:

ls /dev/ttyCH343USB*

The first number is for Arm® Cortex®-A55.

Minicom

Use the following commands to install and run the Minicom program:

1. Install Minicom using Ubuntu package manager

sudo apt-get install minicom

2. Launch Minicom using a console window using the port number determined earlier

sudo minicom /dev/ttyCH343USB * -s

Configure Minicom as show in Figure and Exit configure.

Serial Communication Console Setup

The WCH USB-serial chip on FRDM-IMX91 enumerates 2 serial ports. Assume that the ports are COM11,COM12. The first Port(COM11) is for the serial console communication from Arm® Cortex®-A55. The serial-to-USB drivers are available at CH342F Windows Driver .

Note: To determine the port number of the i.MX board virtual COM port, open the Windows device manager and find USB serial Port in Ports (COM and LPT).

Tera Term

Tera Term is an open source terminal emulation application. This program displays the information sent from the NXP development platform’s virtual serial port.

1. Download Tera Term. After the download, run the installer and then return to this webpage to continue
2. Launch TeraTerm. The first time it launches, it shows the following dialog. Select the Serial option. Assuming your board is plugged in, there should be a COM port automatically populated in the list
3. Configure the serial port settings (using the COM port number identified earlier) to 115,200 baud rate, 8 data bits, no parity and 1 stop bit. To do this, go to Setup → Serial Port and change the settings
4. Verify that the connection is open

PuTTY

PuTTY is a popular terminal-emulation application. This program displays the information sent from the NXP development platform's virtual serial port.

1. Download PuTTY. After the download, run the installer and then return to this webpage to continue
2. Launch PuTTY by either double clicking on the executable file you downloaded or from the Start menu, depending on the type of download you selected
3. Configure In the window that launches. Select the Serial radio button and enter the COM port number that you determined earlier. Also enter the baud rate, in this case 115,200
4. Click Open to open the serial connection. Assuming the board is connected, and you entered the correct COM port, the terminal window opens. If the configuration is not correct, PuTTY alerts you

Security and Integrity

System security and integrity is always one of the most critical aspects to be considered in product development.

FRDM-IMX91 support secure boot feature and encrypted boot feature, helping to prevent unauthorized software execution during the device boot sequence and protect bootloader data from unauthorized access.

For more details of secure boot feature, please check application note AN12312 “Secure Boot on AHAB Supported Devices”.

For more details of encrypted boot feature, please check application note AN13994 “i.MX Encrypted Boot on AHAB-Enabled Devices”.

Fast Boot

In certain use cases, there is requirement for the device boot time, which means the device needs to complete booting in a given time limit.

To optimize the boot time, FRDM-IMX91 supports falcon mode in U-Boot. Falcon mode is a feature in U-Boot that enables fast booting by allowing SPL to directly start the Linux kernel. It completely skips the U-Boot loading and initialization, with the effect of reducing the time spent in the bootloader.

For how to enable falcon mode and further optimize boot time, please check AN14093 “Fast Boot on i.MX 8M and i.MX 9 Using Falcon Mode and Kernel Optimizations”.

Communities

• FRDM-IMX91 Community Trainings
• FRDM-IMX91 Connectivity training