diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.imximage | 30 | ||||
| -rw-r--r-- | doc/README.mxc_hab | 48 |
2 files changed, 75 insertions, 3 deletions
diff --git a/doc/README.imximage b/doc/README.imximage index 802eb90..dcda200 100644 --- a/doc/README.imximage +++ b/doc/README.imximage @@ -15,9 +15,6 @@ Booting from NOR flash does not require to use this image type. For more details refer Chapter 2 - System Boot and section 2.14 (flash header description) of the processor's manual. -This implementation does not use at the moment the secure boot feature -of the processor. The image is generated disabling all security fields. - Command syntax: -------------- ./tools/mkimage -l <mx u-boot_file> @@ -86,6 +83,33 @@ Configuration command line syntax: Example: BOOT_FROM spi + CSF value + + Total size of CSF (Command Sequence File) + used for Secure Boot/ High Assurance Boot + (HAB). + + Using this command will populate the IVT + (Initial Vector Table) CSF pointer and adjust + the length fields only. The CSF itself needs + to be generated with Freescale tools and + 'manually' appended to the u-boot.imx file. + + The CSF is then simply concatenated + to the u-boot image, making a signed bootloader, + that the processor can verify + if the fuses for the keys are burned. + + Further infos how to configure the SOC to verify + the bootloader can be found in the "High + Assurance Boot Version Application Programming + Interface Reference Manual" as part of the + Freescale Code Signing Tool, available on the + manufacturer's website. + + Example: + CSF 0x2000 + DATA type address value type: word=4, halfword=2, byte=1 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. |