# LetsTrust-TPM LetsTrust-TPM is a TPM2.0 daughter board for the Raspberry Pi platform based on an Infineon SLB9670 chip. It is compatible with all Raspberry Pi models and probably the smallest available addon board on the market. The TPM can be used e.g. as a secure keystore or as an hardware random number generator. In order to use it your kernel must have the following options enabled: ```kernelconfig CONFIG_HW_RANDOM_TPM=m CONFIG_TCG_TPM=m CONFIG_TCG_TIS_CORE=m CONFIG_TCG_TIS_SPI=m CONFIG_SECURITYFS=y ``` and a suitable device tree overlay: ```dts slb9670: slb9670@0{ compatible = "infineon,slb9670"; reg = <1>; /* CE1 */ #address-cells = <1>; #size-cells = <0>; spi-max-frequency = <32000000>; status = "okay"; }; ``` Per default CE1 is used as chip select, CE0 can also be used by re-soldering a 0-ohm resistor. A full dts overlay is available here, or you can also find a pre-compiled image with TPM support and the complete build-instructions at letstrust.de.