Hardware requirements
Micro USB cable
MCX-N5XX-EVK board
Personal Computer
Board settings
MCUBoot layout for the internal flash is the following:
MCUBoot region 0x0100_8000 - 0x0100_FFFF : 32kB Primary slot 0x0000_0000 - 0x0010_0000 : 1024kB Secondary slot 0x0010_0000 - 0x0200_0000 : 1024kB
MCUBoot resides in the Bank_1 IFR_0 region
MCUBoot header size is set to 1024 bytes
Signing algorithm is ECDSA-P256
Write alignment is 16 bytes
MCUBoot is configured to use its DIRECT_XIP image handling strategy
Flash swapping HW feature is used for zero-overhead image swapping
Image signing example:
imgtool sign –key sign-ecdsa-p256-priv.pem –align 16 –version 1.1 –slot-size 0x100000 –header-size 0x400 –pad-header ota_mcuboot_basic.bin ota_mcuboot_basic.SIGNED.bin
Note that for the first image flashed manually together with the bootloader additional imgtool options “–pad” and “–confirm” must be used. Otherwise the bootloader would reject the image for missing data in the trailer area.
If the toolchain used for build has problems with writing the bootloader to the IFR flash region, an alternative can be to use NXP blhost utility or the MCUXpresso Secure Provisioning Tool.
IMPORTANT: The CMPA region must be configured so that ROM loader boots from the IFR region. This is done by setting the BOOT_CFG.BOOT_SRC field to 0b10. This value directs the ROM loader to start execution from the IFR region where MCUboot is located. Default CMPA setup with this particular field set is attached to this example in cmpa.bin binary file. To flash this configuration together with MCUboot binary the following blhost commands can be used. Note that the board must be in the ISP mode to use the following commands:
#Erase IFR0 Bank 1 region
blhost -u 0x1FC9,0x014F – flash-erase-region 0x01008000 32768 0
#Flash MCUboot
blhost -u 0x1FC9,0x014F – write-memory 0x01008000 mcuboot_opensource.bin
#Flash CMPA
blhost -u 0x1FC9,0x014F – write-memory 0x01004000 cmpa.bin