Intel® Stratix® 10 Hard Processor System Remote System Update User Guide

ID 683021
Date 4/05/2023
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2.9. RSU Notify

The SDM provides a command called RSU Notify that the HPS software can use to let the SDM know the current HPS software state as a 16-bit numerical value.

If the HPS watchdog timeout triggers an RSU failure, the next application or factory image is loaded. When the HPS queries the RSU state, after the next load, the top 16 bits are 0xf006 and the bottom 16 bits contain the last RSU Notify value reported to the SDM before the watchdog timeout.

The RSU Notify command is automatically called with a value of:
  • 1—from FSBL just before SSBL is entered
  • 2—from SSBL just before the control is passed to the operating system

You can also call RSU Notify with a custom value from either U-Boot or LIBRSU. Avoid using values of 0, 1, or 2, to not conflict with the automatically reported values.

Decoding the reported RSU Notify value:
Value Description
0 FSBL either did not complete or did not reach the point of launching SSBL.
1 FSBL did complete, but SSBL either did not complete or did not reach the point of launching the operating system.
2 Both FSBL and SSBL are complete and attempting to launch the operating system.
Custom You reported this custom value from either U-Boot or LIBRSU.
Note: Only the last reported data before the watchdog timeout is recorded.
Note: This data is lost on nConfig or POR. It only survives a reconfiguration caused by a watchdog timeout, when the watchdog is configured to trigger an RSU reconfiguration.