Hello,
I'm preparing the next set of patches for Measured Boot support in TF-A, please find some details on design and implementation below.
1. SHA256/384/512 hash algorithm for Measured Boot related hash calculations is passed as an existing build 'HASH_ALG' build parameter.
2. BL1 calculates BL2 image hash and passes these data to BL2 via FW_CONFIG/TB_FW_CONFIG device tree in new 'bl2_hash_data' byte array added in 'fvp_fw_config.dts'.
These changes are part of the patch under review, please see https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3555
3. Event Log is calculated by BL2 in Secure Memory and copied to Non-secure memory. Address in Non-secure memory is calculated as:
"nt_fw_config_addr + nt_fw_config_max_size"
with values obtained from 'tb_fw_config':
nt_fw_config_addr = <0x0 0x80000000>; nt_fw_config_max_size = <0x200>;
4. Event Log address and size is passed by TOS_FW_CONFIG and NT_FW_CONFIG device tree in 2 new added properties:
Property name: 'tpm_event_log_addr' Value type is an unsigned 64-bit integer specifying the physical address of the Event Log.
Property name: 'tpm_event_log_size' Value type is an unsigned 32-bit integer specifying the size of the Event Log.
/* TPM Event Log Config */ tpm_event_log { compatible = "arm,nt_fw"; tpm_event_log_addr = <0x0 0x0>; tpm_event_log_size = <0x0>; };
5. TF-A provides Event Log to the BL33 (TFTF/UEFI/U-boot) in 'nt_fw_config' device tree, which address is passed by BL31 as 'arg0' parameter, see TFTF patch:
https://review.trustedfirmware.org/c/TF-A/tf-a-tests/+/3327
6. A new test which validates and prints Event Log data passed in 'nt_fw_config' to BL33 will be added to TFTF.
Please review and provide your comments on the proposed design.
Regards. Alexei.
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