Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 7/19/2024
Public
Document Table of Contents

A.1.2. Booting and Configuration FPGA Configuration First Mode Overview

You can program the Agilex™ 5 SoC device to configure the FPGA first and then boot the HPS. In this mode the FPGA IO and FPGA fabric are configured first, then the HPS EMIF I/O is configured. Finally, the SDM loads the HPS FSBL into the On-Chip RAM and releases the HPS from reset, starting the HPS boot flow.

The FPGA Configuration First Mode flow is shown in the figure below, covering the time from power-on-reset (TPOR) to boot completion (TBoot_Complete).
Figure 327. Typical FPGA Configuration First Boot Flow
Table 428.  FPGA Configuration First Stages The sections following this table describe each stage in more detail.
Time Boot Stage Device State
TPOR to T1 POR Power-on reset
T1 to T2 SDM: Boot ROM
  1. SDM samples the MSEL pins to determine the configuration scheme and boot source.
  2. SDM establishes the device security level based on eFuse values.
  3. SDM initializes the device by reading the configuration firmware (initial part of the bitstream) from the boot source.
  4. SDM authenticates and decrypts the configuration firmware (this process occurs as necessary throughout the configuration).
  5. SDM starts executing the configuration firmware.
T2 to T3 SDM: Configuration Firmware
  1. SDM I/O are enabled.
  2. SDM configures the FPGA I/O and core (full configuration) and enables the rest of your configured SDM I/O.
  3. SDM loads the FSBL from the bitstream into HPS on-chip RAM.
  4. SDM enables HPS SDRAM I/O and optionally enables HPS debug.
  5. FPGA is in user mode.
  6. HPS is released from reset. CPU1-CPU3 are in a wait-for- interrupt (WFI) state.
T3 to T4 First-Stage Boot Loader (FSBL)
  1. HPS verifies the FPGA is in user mode.
  2. The FSBL initializes the HPS, including the SDRAM.
  3. FSBL obtains the SSBL from HPS flash or by requesting flash access from the SDM.
  4. HPS loads SSBL into SDRAM.
  5. HPS peripheral I/O pin mux and buffers are configured. Clocks, resets, and bridges are also configured.
  6. HPS I/O peripherals are available.
T4 to T5 Second-Stage Boot

Loader (SSBL)

  1. HPS bootstrap completes.
  2. OS is loaded into SDRAM.
T5 to TBoot_Complete Operating System

(OS)

The OS boots and applications are scheduled for runtime launch.