diff --git a/doc/imx/habv4/secure_boot.txt b/doc/imx/habv4/secure_boot.txt
deleted file mode 100644
index ae68dc8040..0000000000
--- a/doc/imx/habv4/secure_boot.txt
+++ /dev/null
@@ -1,100 +0,0 @@
-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.