HPS-FPGA Bridge enable

I have Arria 10 board. I follow the instructions on https://rocketboards.org/foswiki/view/Documentation/GSRD161ReleaseNotes to use sdram.img in http://releases.rocketboards.org/release/2016.10/gsrd/bin/linux-socfpga-gsrd-16.1-a10-bin.tar.gz and boot from SD card. After the kernel is up, following directories are empty:

/sys/class/fpga_bridge
/sys/class/fpga_region

I have checked the hardware jumpers are in correct place. dmesg shows:

root@arria10:/sys/class# dmesg | grep fpga
[ 2.022730] fpga_manager fpga0: SoCFPGA Arria10 FPGA Manager registered
[ 2.029685] fpga-region soc:base_fpga_region: FPGA Region probed
root@arria10:/sys/class#

Do you have any idea about the problem?

I guess the bridges are somehow missing/broken in your device tree or the bridge drivers aren’t built properly into your kernel.
I get the following messages on my Cyclone5 board:

[    1.958559] fpga_manager fpga0: Altera SOCFPGA FPGA Manager registered
[    1.965526] altera_hps2fpga_bridge ff400000.fpga-bridge: fpga bridge [lwhps2fpga] registered
[    1.972534] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 25000000Hz, actual 25000000HZ div = 1)
[    1.972587] mmc0: new SDHC card at address 0001
[    1.972926] mmcblk0: mmc0:0001 ASTC 7.44 GiB
[    1.978455]  mmcblk0: p1 p2 p3
[    1.995791] altera_hps2fpga_bridge ff500000.fpga-bridge: fpga bridge [hps2fpga] registered
[    2.004228] altera_hps2fpga_bridge ff600000.fpga-bridge: fpga bridge [fpga2hps] registered
[    2.012896] altera_fpga2sdram_bridge soc:fpga2sdram-bridge: fpga bridge [fpga2sdram] registered
[    2.021576] altera_fpga2sdram_bridge soc:fpga2sdram-bridge: driver initialized with handoff 00000fff
[    2.031012] fpga-region soc:base-fpga-region: FPGA Region probed

Hello,
this thread is probably out-of-date, but the solution should be placed here for other users.
The problem is well known and the solution is described for example at this address:
https://forum.rocketboards.org/t/sys-class-fpga-bridge-empty/444/8
I hope, phuong and thaler had found this too.