User's Manual

9 Interfaces in detail DynaGATE 20-30 User manual Rev. 0-7
9.15 RTC (Real Time Clock)
The DynaGATE 20-30 includes an RTC (Real Time Clocks) device with Fast Reboot Support. A
SuperCAP allows for up to 2 Months Retain.
9.16 TPM
The DynaGATE 20-30 includes a TPM 2.0 hardware module: Infineon SLB9670. This is connected to the
CPU via an SPI interface.
The TPM 2.0 device is fully supported by Linux via the tpm2-tools package that is pre-installed in the
image. This package includes many commands to setup and manage the TPM.
In the DynaGATE 20-30, the TPM device is used for verified boot. This process utilizes the TPM PCR
registers to setup policies to grant access to the TPM NVRAM.
When the system boots, the bootloader measures the boot components and system specific metrics to
produce a set up digital signatures (hashes) that are extended into the PCR registers. When a valid
condition is matched, a policy grants access to the NVRAM so that the bootloader can read the kernel
public key. The key read is used to verify the kernel FIT image. If the kernel is verified OK, the system
loads the kernel and boots it.
A similar scheme is used to retrieve the key that is used to encrypt the user data partition. This is bound to
a different TPM policy.
For more information on the TPM hardware, see: https://www.infineon.com/cms/en/product/security-
smart-card-solutions/optiga-embedded-security-solutions/optiga-tpm/slb-9670vq2.0/
9.17 Watchdog
The DynaGATE 20-30 includes a watchdog / supervisor IC, external to the CPU.
9.18 Accelerometer and Gyroscope
The DynaGATE 20-30 includes a 6-Axis Accelerometer and Gyroscope.
9.19 Programmable pushbutton
The DynaGATE 20-30 provides a programmable pushbutton in the Service Panel.
This pushbutton can be programmed to execute a shell script every time you push it.
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