+++ /dev/null
-1. High Assurance Boot (HAB) for i.MX CPUs
-------------------------------------------
-
-To enable the authenticated or encrypted boot mode of U-Boot, it is
-required to set the proper configuration for the target board. This
-is done by adding the following configuration in the defconfig file:
-
-CONFIG_SECURE_BOOT=y
-
-In addition, the U-Boot image to be programmed into the
-boot media needs to be properly constructed, i.e. it must contain a
-proper Command Sequence File (CSF).
-
-The CSF itself is generated by the i.MX High Assurance Boot Reference
-Code Signing Tool.
-https://www.nxp.com/webapp/sps/download/license.jsp?colCode=IMX_CST_TOOL
-
-More information about the CSF and HAB can be found in the AN4581.
-https://www.nxp.com/docs/en/application-note/AN4581.pdf
-
-We don't want to explain how to create a PKI tree or SRK table as
-this is well explained in the Application Note.
-
-2. Secure Boot on non-SPL targets
----------------------------------
-
-On non-SPL targets a singe U-Boot binary is generated, mkimage will
-output additional information about "HAB Blocks" which can be used
-in the CST to authenticate the U-Boot image (entries in the CSF file).
-
-Image Type: Freescale IMX Boot Image
-Image Ver: 2 (i.MX53/6 compatible)
-Data Size: 327680 Bytes = 320.00 kB = 0.31 MB
-Load Address: 177ff420
-Entry Point: 17800000
-HAB Blocks: 0x177ff400 0x00000000 0x0004dc00
- ^^^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^
- | | |
- | | ----- (1)
- | |
- | ---------------- (2)
- |
- --------------------------- (3)
-
-(1) Size of area in file u-boot-dtb.imx to sign
- This area should include the IVT, the Boot Data the DCD
- and U-Boot itself.
-(2) Start of area in u-boot-dtb.imx to sign
-(3) Start of area in RAM to authenticate
-
-CONFIG_SECURE_BOOT currently enables only an additional command
-'hab_status' in U-Boot to retrieve the HAB status and events. This
-can be useful while developing and testing HAB.
-
-Commands to generate a signed U-Boot using i.MX HAB CST tool:
-# Compile CSF and create signature
-cst --o csf-u-boot.bin --i command_sequence_uboot.csf
-# Append compiled CSF to Binary
-cat u-boot-dtb.imx csf-u-boot.bin > u-boot-signed.imx
-
-3. Secure Boot on SPL targets
------------------------------
-
-This version of U-Boot is able to build a signable version of the SPL
-as well as a signable version of the U-Boot image. The signature can
-be verified through High Assurance Boot (HAB).
-
-After building, you need to create a command sequence file and use
-i.MX HAB Code Signing Tool to sign both binaries. After creation,
-the mkimage tool outputs the required information about the HAB Blocks
-parameter for the CSF. During the build, the information is preserved
-in log files named as the binaries. (SPL.log and u-boot-ivt.log).
-
-Example Output of the SPL (imximage) creation:
- Image Type: Freescale IMX Boot Image
- Image Ver: 2 (i.MX53/6/7 compatible)
- Mode: DCD
- Data Size: 61440 Bytes = 60.00 kB = 0.06 MB
- Load Address: 00907420
- Entry Point: 00908000
- HAB Blocks: 0x00907400 0x00000000 0x0000cc00
-
-Example Output of the u-boot-ivt.img (firmware_ivt) creation:
- Image Name: U-Boot 2016.11-rc1-31589-g2a4411
- Created: Sat Nov 5 21:53:28 2016
- Image Type: ARM U-Boot Firmware with HABv4 IVT (uncompressed)
- Data Size: 352192 Bytes = 343.94 kB = 0.34 MB
- Load Address: 17800000
- Entry Point: 00000000
- HAB Blocks: 0x177fffc0 0x0000 0x00054020
-
-# Compile CSF and create signature
-cst --o csf-u-boot.bin --i command_sequence_uboot.csf
-cst --o csf-SPL.bin --i command_sequence_spl.csf
-# Append compiled CSF to Binary
-cat SPL csf-SPL.bin > SPL-signed
-cat u-boot-ivt.img csf-u-boot.bin > u-boot-signed.img
-
-These two signed binaries can be used on an i.MX in closed
-configuration when the according SRK Table Hash has been flashed.