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Diffstat (limited to 'doc/README.mxc_hab')
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diff --git a/doc/README.mxc_hab b/doc/README.mxc_hab new file mode 100644 index 0000000..97f8b7d --- /dev/null +++ b/doc/README.mxc_hab @@ -0,0 +1,48 @@ +High Assurance Boot (HAB) for i.MX6 CPUs + +To authenticate U-Boot only by the CPU there is no code required in +U-Boot itself. However, 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 Initial Vector Table contains a pointer to the CSF. Please see +doc/README.imximage for how to prepare u-boot.imx. + +The CSF itself is being generated by Freescale HAB tools. + +mkimage will output additional information about "HAB Blocks" +which can be used in the Freescale tooling to authenticate U-Boot +(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: 177ff400 00000000 0004dc00 + ^^^^^^^^ ^^^^^^^^ ^^^^^^^^ + | | | + | | -------- (1) + | | + | ------------------- (2) + | + --------------------------- (3) + +(1) Size of area in file u-boot.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.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 Freescale HAB tools: +cst --o U-Boot_CSF.bin < U-Boot.CSF +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 + +NOTE: U-Boot_CSF.bin needs to be padded to the value specified in +the imximage.cfg file. |