HP ProLiant SL2500 HP ROM-Based Setup Utility User Guide - Page 174

TPM Functionality Enabling TPM Functionality enables the TPM and BIOS secure startup. The TPM is fully functional in this mode. CAUTION: When a TPM is installed and enabled on the server, data access is locked if you fail to follow the proper procedures for updating the system or option firmware, replacing the system board, replacing a hard drive, or modifying OS application TPM settings. For information on installing and enabling the TPM module option, see the HP Trusted Platform Module Option Installation Instructions that ships with the option. Disabling TPM Functionality disables the BIOS secure startup but still allows the TPM to be visible to the operating system. The TPM can respond to most commands in this mode. Selecting Disabled may prevent the server from booting to a TPM-aware operating system. TPM Visibility The TPM Visibility option provides the ability to hide the TPM from the operating system. When the TPM is hidden, BIOS secure startup is disabled, and the TPM does not respond to any commands from any software. Hiding the TPM may prevent the server from booting to a TPM-aware operating system. TPM Expansion ROM Measuring TPM Expansion ROM Measuring enables the BIOS to measure the optional PCI or PCIe expansion ROM code and store that measurement in the TPM. On subsequent reboots, operating systems or validation software that utilize the measurements stored in the TPM can use this data to detect modifications to PCI or PCIe expansion ROM versions. 174 RBSU menu-driven interface, version 2.xx (G5 and earlier servers)