yingshuoxi/openwifi-hw

FPGA (chip) design of openwifi (IEEE 802.11)

openwifi-hw

openwifi: Linux mac80211 compatible full-stack IEEE802.11/Wi-Fi design based on SDR (Software Defined Radio).

[Introduction] [Build FPGA] [Modify IP cores] [Simulate IP cores]

Introduction

This repository includes Hardware/FPGA design. To be used together with openwifi driver and software repository.

Openwifi code has dual licenses. AGPLv3 is the opensource license. For non-opensource and advanced feature license, please contact [email protected]. Openwifi project also leverages some 3rd party modules. It is user's duty to check and follow licenses of those modules according to the purpose/usage. You can find an example explanation from Analog Devices for this compound license conditions. [How to contribute].

Pre-compiled FPGA files: boards/$BOARD_NAME/sdk/ has FPGA bit file, ila .ltx file (if ila inserted) and other initilization files.

Environment variable BOARD_NAME options:

• zc706_fmcs2 (Xilinx ZC706 board + FMCOMMS2/3/4)
• zed_fmcs2 (Xilinx zed board + FMCOMMS2/3/4) -- Vivado license NOT needed
• adrv9364z7020 (ADRV9364-Z7020 + ADRV1CRR-BOB) -- Vivado license NOT needed
• adrv9361z7035 (ADRV9361-Z7035 + ADRV1CRR-BOB/FMC)
• zc702_fmcs2 (Xilinx ZC702 board + FMCOMMS2/3/4) -- Vivado license NOT needed
• antsdr (MicroPhase enhanced ADALM-PLUTO SDR. Notes) -- Vivado license NOT needed
• zcu102_fmcs2 (Xilinx ZCU102 board + FMCOMMS2/3/4)

Build FPGA

• Pre-conditions:

  • Xilinx Vivado (with SDK and HLS) 2018.3
  • Install the evaluation license of Xilinx Viterbi Decoder into Vivado.
  • Ubuntu 18/20 LTS release (We test in these OS. Other OS might also work.)

• Prepare Analgo Devices HDL library (only run once):

export XILINX_DIR=your_Xilinx_directory
(Example: export XILINX_DIR=/opt/Xilinx)
./prepare_adi_lib.sh $XILINX_DIR

• Prepare Analgo Devices specific ip (only run once for each board you have):

export BOARD_NAME=your_board_name
(Example: export BOARD_NAME=zc706_fmcs2)
./prepare_adi_board_ip.sh $XILINX_DIR $BOARD_NAME
(Don't need to wait till the building end. When you see "Building ABCD project [...", you can stop it.)

• Get the openofdm_rx into ip directory (only run once after openofdm is udpated):

./get_ip_openofdm_rx.sh

• Launch Vivado:

cd openwifi-hw/boards/$BOARD_NAME/
source $XILINX_DIR/Vivado/2018.3/settings64.sh
vivado

• In Vivado:

source ./openwifi.tcl
Open Block Design
Tools --> Report --> Report IP Status
Generate Bitstream
(Will take a while)
File --> Export --> Export Hardware... --> Include bitstream --> OK
File --> Launch SDK --> OK, then close SDK

• In Linux, store the FPGA files to a specific directory:

cd openwifi-hw/boards
./sdk_update.sh $BOARD_NAME

• Add the FPGA files to git (only if you want):

git add $BOARD_NAME/sdk/*
git commit -m "new fpga img for openwifi (or comments you want to make)"
git push

"git lfs (Git Large File Storage)" operation is recommended for system_top.bit and system.hdf before git add (avoid too big repo!)

Modify IP cores

IP core source files are in "ip" directory. After IP is modified, export the IP core into "ip_repo" directory. Then re-run the full FPGA build procedure. For IP project created by _high.tcl or _low.tcl or _ultra_scale.tcl, exporting target directory should be ip_repo/high/ or ip_repo/low/ or ip_repo/ultra_scale/ (for ZynqMP SoC, like zcu102 board). Other IP should be exported to ip_repo/common/ (except that the side channel module has small/big postfix).

• IP cores designed by HLS (mixer_duc):

Create a project "mixer_duc" with file in ip/mixer_duc/src directory in Vivado HLS.
During creating, set mixer_duc as top, select zc706 board as "Part" and set Clock Period 5 (means 200MHz).
Run C synthesis.
Click solution1, Solution --> Export RTL
Copy project_directory/solution1/impl/ip to ip_repo/common/mixer_duc

• IP cores designed by block-diagram (duc_bank_core_low, duc_bank_core_high, etc). duc_bank_core_high as example:

Open Vivado, then in Vivado Tcl Console:
cd ip/duc_bank_core_high
source ./duc_bank_core_high.tcl
In Vivado:
Open Block Design
Tools --> Report --> Report IP Status
Tools --> Create and Package New IP... --> Next --> Package a block design from ... --> Next --> set "ip_repo/high/duc_bank_core" as target directory --> Next --> OK -- Finish
In new opened temporary project: Review and Package --> Package IP --> Yes

• IP cores designed by verilog (rx_intf, xpu, etc). xpu as example:

Open Vivado, then in Vivado Tcl Console:
cd ip/xpu
source ./xpu_high.tcl
In Vivado:
Tools --> Report --> Report IP Status
Tools --> Create and Package New IP... --> Next --> Next --> set "ip_repo/high/xpu" as target directory --> Next --> OK -- Finish
In new opened temporary project: Review and Package --> Package IP --> Yes

• openofdm_rx: You need to apply the evaluation license of Xilinx Viterbi Decoder and install on your PC firstly.

  • Make sure you already have openofdm files in ip/openofdm_rx. If not, in Linux:

    ./get_ip_openofdm_rx.sh
    

  • Open Vivado, then in Vivado Tcl Console:

    cd ip/openofdm_rx
    source ./openofdm_rx.tcl
    

  • In Vivado:

    Tools --> Report --> Report IP Status
    Tools --> Create and Package New IP... --> Next --> Next --> set "ip_repo/common/openofdm_rx" as target directory --> Next --> OK -- Finish
    In new opened temporary project: Review and Package --> Package IP --> Yes
    

Simulate IP cores

• Create the ip core project in Vivado. To achieve this, you need to follow the previous section till you execute "source ./ip_name.tcl" in Vivado

• Normally you should see the top level testbench (..._tb.v) of that ip core in the Vivado "Sources" window (take openofdm_rx as example):

    Sources --> Simulation Sources --> sim_1 --> dot11_tb
  

• To run the simulation, click "Run Simulation" --> "Run Behavoiral Simulation" under the "SIMULATION" in the "PROJECT MANAGER" window. It will take quite long time for the 1st time run due to the sub-ip-core compiling. Fortunately the sub-ip-core compiling is a time consuming step that occurs only one time.

• When the previous step is finished, you should see a simulation window displays many variable names and waveforms. Now click the small triangle, which points to the right and has "Run All (F3)" hints, on top to start the simulation.

• Please check the ..._tb.v to see how do we use $fopen, $fscanf and $fwrite to read test vectors and save the variables we want to check later. Of course you can also check everything in the waveform window.

• After you modify some design files, just click the small circle with arrow, which has "Relaunch Simulation" hints, on top to re-launch the simulation.

• You can always drag the signals you need from the "SIMULATION" --> "Scope" window to the waveform window, and relaunch the simulation to check those signals' waveform. An example:

    SIMULATION --> Scope --> Name --> dot11_tb --> dot11_inst --> ofdm_decoder_inst --> viterbi_inst
  

Note: openwifi adds necessary modules/modifications on top of Analog Devices HDL reference design. For general issues, Analog Devices wiki pages would be helpful!

Notes: The 802.11 ofdm receiver is based on openofdm project. You can find our patch (bug-fix, improvement) here which is mapped to ip/openofdm_rx.