Kontron Electronics i.MX8MM SoMs and Boards

The SL i.MX8MM and OSM-S i.MX8MM by Kontron Electronics GmbH are SoM modules with an i.MX8M-Mini SoC, 1/2/4 GB LPDDR4 RAM, SPI NOR, eMMC and PMIC.

The matching evaluation boards (Board-Line, BL) have two Ethernet ports, USB 2.0, HDMI/LVDS, SD card, CAN, RS485, RS232 and much more.

The OSM-S i.MX8MM is compliant to the Open Standard Module (OSM) 1.1 specification, size S (https://sget.org/standards/osm).

Quick Start

  • Get and Build the Trusted Firmware-A (TF-A)

  • Get the DDR firmware

  • Build U-Boot

  • Boot

Note

To build on a x86-64 host machine, you need a GNU cross toolchain for the target architecture (aarch64). Check your distros package manager or download and install the necessary tools (aarch64-linux-gnu-*) manually.

Get and Build the Trusted Firmware-A (TF-A)

There are two sources for the TF-A. Mainline and NXP. Get the one you prefer (support and features might differ).

Note

If you are using GCC 12 and you get compiler/linker errors, try to add the following arguments to your make command as workaround: CFLAGS="-Wno-array-bounds" LDFLAGS="--no-warn-rwx-segments"

NXP’s imx-atf

  1. Get TF-A from: https://github.com/nxp-imx/imx-atf, branch: lf_v2.6

  2. Build

$ make PLAT=imx8mm CROSS_COMPILE=aarch64-linux-gnu- IMX_BOOT_UART_BASE="0x30880000" bl31
$ cp build/imx8mm/release/bl31.bin $(builddir)

Note

builddir is U-Boot’s build directory (source directory for in-tree builds)

Mainline TF-A

  1. Get TF-A from: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/, tag: v2.4

  2. Build

$ make PLAT=imx8mm CROSS_COMPILE=aarch64-linux-gnu- IMX_BOOT_UART_BASE="0x30880000" bl31
$ cp build/imx8mm/release/bl31.bin $(builddir)

Get the DDR firmware

$ wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-imx-8.18.bin
$ chmod +x firmware-imx-8.18.bin
$ ./firmware-imx-8.18.bin
$ cp firmware-imx-8.18/firmware/ddr/synopsys/lpddr4_pmu_train_1d_imem.bin $(builddir)
$ cp firmware-imx-8.18/firmware/ddr/synopsys/lpddr4_pmu_train_1d_dmem.bin $(builddir)
$ cp firmware-imx-8.18/firmware/ddr/synopsys/lpddr4_pmu_train_2d_imem.bin $(builddir)
$ cp firmware-imx-8.18/firmware/ddr/synopsys/lpddr4_pmu_train_2d_dmem.bin $(builddir)

Build U-Boot

$ make kontron-sl-mx8mm_defconfig
$ make CROSS_COMPILE=aarch64-linux-gnu-

Copy the flash.bin to SD card at an offset of 33 KiB:

$ dd if=flash.bin of=/dev/sd[x] bs=1K seek=33 conv=notrunc

Boot

Put the SD card in the slot on the board and apply power. Check the serial console for output.

Flash the Bootloader to SPI NOR

  1. Determine and note the exact size of the flash.bin image in bytes (e.g. by running ls -l flash.bin)

  2. On the U-Boot CLI copy the bootloader from SD card to RAM:

    mmc dev 1
mmc read $loadaddr 0x42 0x1000

  3. Erase the SPI NOR flash:

    sf probe
sf erase 0x0 0x200000

  4. Copy the bootloader from RAM to SPI NOR. For the last parameter of the command, use the size determined in step 1 in hexadecimal notation:

    sf write $loadaddr 0x400 0x13B6F0

Note

To be able to boot from SPI NOR the OTP fuses need to be set accordingly.

Further Information

The bootloader configuration is setup to be used with kernel FIT images. Legacy images might not be working out of the box.

Please see https://docs.kontron-electronics.de for further vendor documentation.