Imx8mp boot TEZI from SD card

M_P · May 11, 2026, 10:56am

Hello,

i have a verdin imx8mp module on a custom carrier board and want to boot the toradex easy installer from sd card.

If I format a USB-stick in FAT32 and copy TEZI files on it, I can boot the easy installer from USB-stick via run bootcmd_usb0 from uboot.

But if i format a SD card in the same way as the usb-stick in FAT32 and copy the same TEZI files on it, I am not able to boot it. If I run bootcmd_mmc1 from uboot, nothing happens.

Verdin iMX8MP # run bootcmd_mmc1
Verdin iMX8MP #

I have tried with Verdin-iMX8MP_ToradexEasyInstaller_7.7.0-devel-20260507+build.509 and Verdin-iMX8MP_ToradexEasyInstaller_7.6.0+build.11 images from here:
Download Toradex Easy Installer | Toradex Developer Center

If I boot the yocto from MMC, I can mount the SD card and see the TEZI files on. I therefore think that the connection on our custom carrie boards is fine.

The SD card is an Intenso microSD HC class 4 4GB card.

tdx-info output is:

Software summary
------------------------------------------------------------
Bootloader:               U-Boot
Kernel version:           6.6.23-7.7.0-devel-g558ba3740880 #1 SMP PREEMPT Wed Se                                                                                                                                                                                                                                             p 25 11:25:16 UTC 2024
Kernel command line:      root=PARTUUID=e0f7b099-02 ro rootwait console=tty1 con                                                                                                                                                                                                                                             sole=ttymxc2 clk-imx8mp.mcore_booted=1
Distro name:              NAME="TDX Wayland with XWayland"
Distro version:           VERSION_ID=7.7.0-devel-20260422135554-build.0
Hostname:                 verdin-imx8mp-15460392
------------------------------------------------------------

Hardware info
------------------------------------------------------------
HW model:                 Toradex Verdin iMX8M Plus on Verdin Development Board
Toradex version:          0063 V1.1B
Serial number:            15460392
Processor arch:           aarch64
------------------------------------------------------------

ToradexAI · May 11, 2026, 10:57am

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

Based on your issue with booting Toradex Easy Installer from SD card on Verdin iMX8M Plus, there are several factors to consider for proper SD card boot configuration.

SD Card Boot Requirements

For booting from an SD card, you need an SD card with two partitions: a FAT partition to store the kernel image and device trees, and an ext4 partition to store the rootfs (1). However, for Toradex Easy Installer, the setup is different.

Proper SD Card Preparation for TEZI

When using Toradex Easy Installer from external media, you should unzip the Easy Installer package and copy all contents to the root directory of the external media (2). The SD card should contain files like:

.
├── boot.scr
├── image.json
├── imx-boot-recoverytezi
├── imx-boot-sd
├── overlays.txt
├── recovery
├── tezi.itb
├── tezi.png
└── wrapup.sh

(2)

U-Boot Configuration

The issue might be related to your U-Boot configuration. The default U-Boot uses distroboot functionality which boots in the following order: SD Card, internal eMMC, USB Stick (2).

You can verify if your SD card is being detected by checking the partitions at the U-Boot prompt:

> mmc dev 1; mmc part

(1)

Alternative Approach

If the standard run bootcmd_mmc1 doesn’t work, you can try using the distroboot command which searches for bootable media:

> run distro_bootcmd

(3)

Troubleshooting Steps

Verify SD card detection: Ensure your custom carrier board’s SD card interface is properly connected and the card is detected by U-Boot
Check boot.scr: Make sure the boot.scr file is present in the root directory of your SD card
Test with different SD card: Try using a different SD card or a higher class card
Verify file integrity: Ensure all TEZI files were copied correctly without corruption

Important Note

Make sure there is no bootable SD card plugged into the slot when trying to enter recovery mode, as the module will try to boot from the external SD card instead of going into the USB serial loader (4).

Since USB boot works but SD card boot doesn’t, this suggests a potential issue with either the SD card hardware interface on your custom carrier board or the SD card preparation. The fact that you can mount and read the SD card from Linux indicates the hardware connection is functional, so the issue is likely related to the boot configuration or file setup.

Best regards, Toradex AI Assistant.

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M_P · May 11, 2026, 11:08am

Is the ext4 partition needed if I just want to boot the easy installer?
It boots from a FAT32 USB device without an ext4 partition.

The SD card contains all files from TEZI dowload archive in root directory

d-----        11.05.2026     09:56                recovery
-a----        11.05.2026     09:56           2137 boot.scr
-a----        11.05.2026     09:56           1504 image.json
-a----        11.05.2026     09:56        1378288 imx-boot-recoverytezi
-a----        11.05.2026     09:56        1380976 imx-boot-sd
-a----        11.05.2026     09:56            118 overlays.txt
-a----        11.05.2026     09:56            491 recovery-linux.README
-a----        11.05.2026     09:56            362 recovery-linux.sh
-a----        11.05.2026     09:56            273 recovery-windows.bat
-a----        11.05.2026     09:56           1464 recovery-windows.README
-a----        11.05.2026     09:56       42518111 tezi.itb
-a----        11.05.2026     09:56           2997 tezi.png
-a----        11.05.2026     09:56             18 wrapup.sh

output of mmc dev1; mmc part:

Verdin iMX8MP # mmc dev 1; mmc part
MMC Device 0 not found
no mmc device at slot 0

ToradexAI · May 11, 2026, 11:08am

SD Card Boot Requirements

You’re correct - the ext4 partition is not needed for booting Toradex Easy Installer from SD card (1). The two-partition requirement (FAT + ext4) mentioned in my previous response applies to booting a full OS image from SD card, not TEZI itself (1).

For Toradex Easy Installer, you only need the FAT32-formatted SD card with all TEZI files in the root directory, exactly as you have it set up (2).

MMC Device Detection Issue

The critical issue is revealed in your U-Boot output:

Verdin iMX8MP # mmc dev 1; mmc part
MMC Device 0 not found
no mmc device at slot 0

This indicates that U-Boot cannot detect the SD card at all. The command should show the SD card partitions if properly detected (1).

Troubleshooting Steps

1. Check MMC Device Numbers

Try different MMC device numbers to identify which slot your SD card is connected to:

> mmc dev 0; mmc part
> mmc dev 2; mmc part

2. Verify Hardware Connection

Since the SD card works when booted into Linux but not in U-Boot, this suggests:

The SD card interface may not be properly initialized in U-Boot on your custom carrier board
There might be missing device tree configuration for the SD card interface in U-Boot
Power or clock configuration issues for the SD card controller

3. Alternative Boot Method

Since USB boot works reliably, you can use the alternative approach described in the documentation. From U-Boot, try the distro boot command which searches all available boot devices:

> run distro_bootcmd

This will attempt to boot from SD card first, then internal eMMC, then USB stick according to the configured boot order (2).

Root Cause Analysis

The fact that:

USB boot works perfectly
SD card is readable from Linux
U-Boot cannot detect the SD card (MMC Device 0 not found)

This points to a U-Boot configuration issue specific to your custom carrier board’s SD card interface, rather than a TEZI file preparation problem.

Best regards, Toradex AI Assistant.

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If I answered your question, please tick the “Solution” checkbox.

For follow-up questions to me, please use @ToradexAI in your post.

M_P · May 11, 2026, 11:18am

What are the requirements on the SD card?
Is a microSD HC class4 4GB OK?
Is FAT32 with 4kB cluster size ok?

Maximiliano.tx · May 11, 2026, 1:29pm

Hello @M_P

would it be possible for you to test in one of our carrier boards? to be sure that this is not a hw issue in your design as this should work.

Also, are you trying to create sort of offline update system or what is the intend?

thanks