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author | Tom Rini <trini@konsulko.com> | 2015-03-05 07:22:18 -0500 |
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committer | Tom Rini <trini@konsulko.com> | 2015-03-05 07:22:18 -0500 |
commit | 02ebe6f702ec8d025926b0ea7c2088e302c5a302 (patch) | |
tree | 15e249ac39e9c547668327218e63a0faf54a3283 /doc/README.mxc_hab | |
parent | 7ae8350f67eea861280a4cbd2d067777a0e87153 (diff) | |
parent | 32df39c741788e8637cffe6633d73594b26d70fb (diff) | |
download | u-boot-imx-02ebe6f702ec8d025926b0ea7c2088e302c5a302.zip u-boot-imx-02ebe6f702ec8d025926b0ea7c2088e302c5a302.tar.gz u-boot-imx-02ebe6f702ec8d025926b0ea7c2088e302c5a302.tar.bz2 |
Merge branch 'master' of git://www.denx.de/git/u-boot-imx
Diffstat (limited to 'doc/README.mxc_hab')
-rw-r--r-- | doc/README.mxc_hab | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/doc/README.mxc_hab b/doc/README.mxc_hab index 43e64a2..e9340dd 100644 --- a/doc/README.mxc_hab +++ b/doc/README.mxc_hab @@ -46,3 +46,51 @@ cat u-boot.imx U-Boot_CSF_pad.bin > u-boot-signed.imx NOTE: U-Boot_CSF.bin needs to be padded to the value specified in the imximage.cfg file. + +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 Freescale's Code +Signing Tool (CST). The CST replaces only the image data of +u-boot.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: + +CONFIG_SECURE_BOOT +CONFIG_SYS_FSL_SEC_COMPAT 4 /* HAB version */ +CONFIG_FSL_CAAM +CONFIG_CMD_DEKBLOB + +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. + +objcopy -I binary -O binary --pad-to 0x2000 --gap-fill=0x00 \ + U-Boot_CSF.bin U-Boot_CSF_pad.bin +cat u-boot.imx U-Boot_CSF_pad.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. |