7.1.1. DTB binding for Event Log properties

This document describes the device tree format of Event Log properties. These properties are not related to a specific platform and can be queried from common code.

7.1.1.1. Dynamic configuration for Event Log

Measured Boot driver expects a tpm_event_log node with the following field in ‘tb_fw_config’, ‘nt_fw_config’ and ‘tsp_fw_config’ DTS files:

  • compatible [mandatory]
    • value type: <string>

    • Must be the string “arm,tpm_event_log”.

Then a list of properties representing Event Log configuration, which can be used by Measured Boot driver. Each property is named according to the information it contains:

  • tpm_event_log_sm_addr [fvp_nt_fw_config.dts with OP-TEE]
    • value type: <u64>

    • Event Log base address in secure memory.

Note. Currently OP-TEE does not support reading DTBs from Secure memory and this property should be removed when this feature is supported.

  • tpm_event_log_addr [mandatory]
    • value type: <u64>

    • Event Log base address in non-secure memory.

  • tpm_event_log_size [mandatory]
    • value type: <u32>

    • Event Log size.