Agilex 5 - configure FPGA from running linux via dt-overlay

Hi all,

finally I solved issues with help from Arrow (thank you Tomasz). The necessary things were:

1) to modify u-boot script to exclude any accesses to fabric peripherals (eg USB reset PIO)

echo "Trying to boot Linux from device ${target}";

if test ${target} = "mmc0"; then

  mw.l 10d13224 14;
  mw.l 10d13228 14;
  mw.l 10d1323c 14;
  mw.l 10d13234 14;
  mw.l 10d13248 14;
  mw.l 10d1324C 14;
  mw.l 0x10D11028 0x01027fb0 1;
  mw.l 0x10c03304 0x410 1;
  mw.l 0x10c03300 0x00000410;
  mw.l 0x10c03300 0x00000000;
  mw.l 0x10c03300 0x00000410;

else
    echo "mmc0 not found!"
fi

fatload mmc 0:1 ${loadaddr} ${bootfile};
setenv bootargs "bootargs console=ttyS0,115200 root=${mmcroot} rw rootwait";
bootm ${loadaddr};

if test ${target} = "qspi"; then
  qspi_clock=0x17d78400;
  if ubi part root; then
    ubi detach;
    mtdparts;
    ubi part root;
    ubi readvol ${loadaddr} kernel;
    ubi detach;
    setenv bootargs "earlycon panic=-1 ubi.mtd=1 root=ubi0:rootfs rootfstype=ubifs rw rootwait";
    bootm ${loadaddr};
  fi
  ubi detach;
  sf probe;
  sf read ${loadaddr} ${qspibootimageaddr} ${bootimagesize};
  setenv bootargs "earlycon root=/dev/mtdblock1 rw rootfstype=jffs2 rootwait";
  bootm ${loadaddr};
fi

if test ${target} = "nand"; then
  ubi part root;
  ubi readvol ${loadaddr} kernel;
  setenv bootargs "earlycon panic=-1 root=${nandroot} rw rootwait rootfstype=ubifs ubi.mtd=1";
  bootm ${loadaddr};
fi

2.) To modify and rebuild the devicetree (socfpga_agilex5_axe5_eagle.dts). Remove any references to fabric peripherals - so LEDs sections, whole soc@0 section and &usb31 section.

overlay.dts was also simplified

// SPDX-License-Identifier:     GPL-2.0
/*
 * Copyright (C) 2024, Arrow Electronics, Incorporated.
 */

/dts-v1/;
/plugin/;

/ {

  fragment@0 {
    target-path = "/soc@0/base_fpga_region";
    __overlay__ {
      firmware-name = "axe5_eagle_top.hps.core.rbf";
      config-complete-timeout-us = <30000000>;
    };
  };
};

and now fpga_core.rbf can be (for first time) succesfully load also from linux system.