Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 10/10/2025
Public
Document Table of Contents

A.2.2.1. Feature Availability under SDM/HPS Ownership of Quad SPI Controller

The SDM or HPS cannot execute any feature or application that requires access to the QSPI device unless it has ownership of the QSPI controller.

This includes operations such as retrieving items from the QSPI, like the Linux file system, an encryption key, phase 2, partial reconfiguration FPGA image, and others. If the SDM has ownership of the QSPI controller, the HPS cannot access the QSPI device for reading or writing, and vice versa.

The following table describes the QSPI controller ownership requirement for different device functionalities.

Note: Starting from Quartus® Prime Pro Edition software version 25.1, you need to select in the Quartus® Prime software the QSPI controller ownership (for SDM or HPS) based on the QSPI related features that your project requires to support. The QSPI Ownership selection feature lacks backward compatibility, therefore Altera does not recommend mixing .sof files created with Quartus® Prime Pro Edition versions prior 25.1 with SDM firmware created with Quartus version 25.1 and later, and vice versa. Also, for designs with remote system update support, do not use QSPI image bitstreams created before the Quartus version 25.1 release alongside those created with version 25.1 and later releases. For non-RSU hardware designs that must be ported from the Quartus versions prior 25.1 and whose boot flow depends on HPS to load components from the QSPI device (i.e., second stage bootloaders, OS components, and others), you must select the HPS as the QSPI owner in Quartus configuration because Quartus assigns the QSPI ownership to SDM by default. Missing this configuration prevents the HPS from successfully loading these components.
Table 421.  QSPI Controller Ownership Requirement
Device

Feature/Application

(QSPI Ownership: HPS/SDM must own)

HPS loading from QSPI flash HPS loading Phase2 bitstream HPS loading Partial Reconfiguration bitstream RSU from HPS Attestation On Boarding BKPS
Agilex™ 5 HPS

HPS: If Phase2 bitstream is in QSPI flash.

SDM: If Phase2 bitstream is encrypted with AES key in QSPI flash. 57

HPS or SDM may own the QSPI controller under other scenarios following the above restrictions.

HPS: If PR bitstream is in QSPI flash.

SDM: If PR bitstream is encrypted with AES key in QSPI flash.57

HPS or SDM may own the QSPI controller under other scenarios following the above restrictions.

HPS SDM SDM SDM
57 When the Phase2 or PR bitstreams are encrypted, the SDM requires the AES key to decrypt these. If the AES key is in the QSPI flash, the SDM must own the QSPI controller so that it can access the key. In this case, Phase2 or PR bitstreams still need to be stored outside of the QSPI flash device so HPS can access them.