1. Setup U-Boot Image for Encrypted Boot ---------------------------------------- An authenticated U-Boot image is used as starting point for Encrypted Boot. The image is encrypted by i.MX Code Signing Tool (CST). The CST replaces only the image data of u-boot-dtb.imx with the encrypted data. The Initial Vector Table, DCD, and Boot data, remains in plaintext. The image data is encrypted with a Encryption Key (DEK). Therefore, this key is needed to decrypt the data during the booting process. The DEK is protected by wrapping it in a Blob, which needs to be appended to the U-Boot image and specified in the CSF file. The DEK blob is generated by an authenticated U-Boot image with the dek_blob cmd enabled. The image used for DEK blob generation needs to have the following configurations enabled in Kconfig: CONFIG_IMX_HAB=y CONFIG_CMD_DEKBLOB=y Note: The encrypted boot feature is only supported by HABv4 or greater. The dek_blob command then can be used to generate the DEK blob of a DEK previously loaded in memory. The command is used as follows: dek_blob <DEK address> <Output Address> <Key Size in Bits> example: dek_blob 0x10800000 0x10801000 192 The resulting DEK blob then is used to construct the encrypted U-Boot image. Note that the blob needs to be transferred back to the host.Then the following commands are used to construct the final image. cat u-boot-dtb.imx csf-u-boot.bin > u-boot-signed.imx objcopy -I binary -O binary --pad-to <blob_dst> --gap-fill=0x00 \ u-boot-signed.imx u-boot-signed-pad.bin cat u-boot-signed-pad.imx DEK_blob.bin > u-boot-encrypted.imx NOTE: u-boot-signed.bin needs to be padded to the value equivalent to the address in which the DEK blob is specified in the CSF.