Stratix® 10 SoC FPGA Boot User Guide

ID 683847
Date 1/15/2025
Public
Document Table of Contents

3.2.3. Single SDM Flash

In this case, the Quad SPI flash connected to the SDM contains all the data required for configuring and booting the system, including the configuration bitstream, bootloader, and OS files.

Note: When you use the HPS to access the SDM Quad SPI, it operates at a lower bandwidth of ~4-6 MB/s. This is due to the high latency of the PSI link between HPS and SDM, and the fact that all transfers are done in Programmed IO (PIO) mode, instead of DMA mode.

The QSPI controller is shared between the SDM and the HPS and only one of these can access the QSPI device at a time. At power-up, the SDM receives access to the QSPI controller. If the HPS needs access to the QSPI flash device, the software running in this (for example, the FSBL or SSBL) must request ownership from the SDM through the HPS-to-SDM mailbox. After the HPS gains ownership of the QSPI controller, it retains ownership until any of the following events occur:

  • A power cycle
  • A cold reset
  • An HPS reboot generated for an RSU event
Depending on the boot stage that performs the FPGA configuration, you have the following options for storing the FPGA core and I/O configuration file:
  • An SDM flash storage partition—In this case the SSBL initiates configuration
  • In the OS file system—In this case the OS initiates configuration
Figure 9. HPS Boot First Layout with Quad SPI