Hardware requirements

  • Mini/micro USB cable

  • MIMXRT1020-EVK board

  • Personal Computer

Board settings

MCUBoot layout

Region

From

To

Size

MCUboot code

0x60000000

0x6003FFFF

256kB

Primary slot

0x60040000

0x6023FFFF

2048kB

Secondary slot

0x60240000

0x6043FFFF

2048kB

  • MCUBoot header size is set to 1024 bytes

  • Signing algorithm is ECDSA-P256

  • Write alignment is 4 bytes

  • MCUBoot is configured to use SWAP_MOVE image handling strategy

Image signing example

imgtool sign   --key sign-ecdsa-p256-priv.pem
               --align 4
               --version 1.1
               --slot-size 0x200000
               --header-size 0x400
               --pad-header
               ota_mcuboot_basic.bin
               ota_mcuboot_basic.SIGNED.bin

Custom configuration - Encrypted XIP

Region

From

To

Size

MCUboot code

0x60000000

0x6003FFFF

256kB

Primary slot

0x60040000

0x6023FFFF

2048kB

Secondary slot

0x60240000

0x6043FFFF

2048kB

Encryption metadata

0x60440000

0x60440FFF

4kB

This custom build generates a project with predefined configuration to utilize Encrypted XIP mode. For more information please see Encrypted XIP and MCUboot.

  • MCUBoot header size is set to 1024 bytes

  • Signing algorithm is ECDSA-P256

  • Write alignment is 4 bytes

  • MCUBoot is configured for Encrypted XIP mode using modified MCUBOOT_OVERWRITE_ONLY image update strategy

  • MCUboot uses ECDH-P256 to secure AES key for image encryption

  • Primary slot is encrypted by BEE module to utilize encrypted XIP

Image signing example:

imgtool sign --key sign-ecdsa-p256-priv.pem
             --align 4
             --version 1.1
             --slot-size 0x200000
             --header-size 0x400
             --max-sectors 59
             --pad-header
             -E enc-ec256-pub.pem
             ota_mcuboot_basic.bin
             ota_mcuboot_basic.SIGNED.bin

Project building example:

The project is built using west tool. For more information please see MCUXpresso SDK documentation.

Bootloader:

west build -p always examples/ota_examples/mcuboot_opensource --toolchain iar --config flexspi_nor_debug -b evkmimxrt1020 -t guiproject -DCONF_FILE="examples/ota_examples/_custom_cfg/rt10xx/mcuboot_opensource.conf" -d builds/mcuboot

OTA application:

west build -p always examples/ota_examples/ota_mcuboot_basic --toolchain iar --config flexspi_nor_debug -b evkmimxrt1020 -t guiproject -DCONF_FILE="examples/ota_examples/_custom_cfg/rt10xx/ota_mcuboot_basic.conf" -d builds/ota_mcuboot_basic