Key-IST Usage Requirements

• DriveOS provides an example implementation of communication between IST_Client and NvMCU_ISTManager using Ethernet. See “MCU Communication Coordinator Daemon” in the MCU Reference Guide. Users of NVIDIA DriveOS are expected to implement this interface for their system.

• The user must not use the GPIO pins reserved for KIST (IST_REQ and IST_DONE_N) independent of the safety MCU software during the KIST test sequence so that NvMCU_ISTManager can signal the KIST boot sequence to the Orin SoC.

• The user must ensure that storage device meets requirements specified in the DriveOS Supported Component List. On Orin, the eMMC storage device must support HS400es mode. The Orin SoC can only communicate with SDMMC (SDMMC4 instance only) storage devices to read the KIST test vectors and write back the results.

• On normal boot, IST_Client will always return the results from the previous execution, even if KIST wasn’t requested/run on previous boot. MCU FW should only use the KIST results from IST_Client if they requested KIST and observed IST_DONE_N.

• After flashing DriveOS software, the KIST results are invalid, and the KIST test must be triggered again to get a valid result.