This repository includes Linux driver and software. [openwifi-hw](https://github.com/open-sdr/openwifi-hw) repository has the FPGA design. It is **YOUR RESPONSIBILITY** to follow your **LOCAL SPECTRUM REGULATION** or use **CABLE** to avoid potential interference over the air.
Openwifi code has dual licenses. AGPLv3 is the opensource license. For non-opensource license, please contact Filip.Louagie@UGent.be. 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](https://github.com/analogdevicesinc/hdl/blob/master/LICENSE) for this compound license conditions. [[How to contribute]](https://github.com/open-sdr/openwifi/blob/master/CONTRIBUTING.md).
- board_name is used to identify FPGA design in openwifi-hw/boards/
- Don't have any boards? Or you like JTAG boot instead of SD card? Check our test bed [w-iLab.t](https://doc.ilabt.imec.be/ilabt/wilab/tutorials/openwifi.html) tutorial.
[[Quick start](#Quick-start)]
[[Basic operations](#Basic-operations)]
[[Update FPGA](#Update-FPGA)]
[[Update Driver](#Update-Driver)]
[[Update sdrctl](#Update-sdrctl)]
[[Easy Access and etc](#Easy-Access-and-etc)]
[[Build openwifi Linux img from scratch](#Build-openwifi-Linux-img-from-scratch)]
- Burn openwifi board specific img file (from the table) into a SD card ("Open With Disk Image Writer". Or "dd" command after unzip). The SD card has two partitions: BOOT and rootfs. You need to config the **correct files in the BOOT partition** according to the **board you have** by operation on your computer:
- After you see the "openwifi" SSID on your device (Phone/Laptop/etc), connect it. Browser to 192.168.13.1 on your device, you should see the webpage hosted by the webserver on board.
- Note 1: If your device doesn't support 5GHz (ch44), please change the **hostapd-openwifi.conf** on board and re-run fosdem.sh.
- Note 2: After ~2 hours, the Viterbi decoder will halt (Xilinx Evaluation License). Just power cycle the board if it happens. (If output of "./sdrctl dev sdr0 get reg rx 20" is always the same, it means the decoder halts)
- To give the Wi-Fii client internet access, configure routing/NAT **on the PC**:
- To monitor **real-time CSI (Chip State Information)**, such as timestamp, frequency offset, channel state, equalizer, please refer to [[CSI notes](doc/app_notes/csi.md)].
The board actually is an Linux/Ubuntu computer which is running **hostapd** to offer Wi-Fi AP functionality over the Wi-Fi Network Interface (NIC). The NIC is implemented by openwifi-hw FPGA design. We use the term **"On board"** to indicate that the commands should be executed after ssh login to the board. **"On PC"** means the commands should run on PC.
- Use openwifi as client to connect other AP (Change wpa-connect.conf on board firstly):
```
route del default gw 192.168.10.1
wpa_supplicant -i sdr0 -c wpa-connect.conf &
dhclient sdr0
```
- Use openwifi in ad-hoc mode: Please check **sdr-ad-hoc-up.sh** and **sdr-ad-hoc-join.sh**.
- Use openwifi in monitor mode: Please check **monitor_ch.sh**.
- The Linux native Wi-Fi tools/Apps (iwconfig/ifconfig/iwlist/iw/hostapd/wpa_supplicant/etc) can run over openwifi NIC in the same way as commercial Wi-Fi chip.
- **sdrctl** is a dedicated tool to access openwifi driver/FPGA, please check doc directory for more information.
- Download [2019_R1-2020_02_04.img.xz](https://swdownloads.analog.com/cse/2019_R1-2020_02_04.img.xz) from [Analog Devices Wiki](https://wiki.analog.com/resources/tools-software/linux-software/zynq_images). Burn it to a SD card.
- Insert the SD card to your Linux PC. Find out the mount point (that has two sub directories BOOT and rootfs), and setup environment variables (use absolute path):
Openwifi only applies OFDM as its modulation scheme and as a result, it is not backward compatible with 802.11b clients or modes of operation. This is usually the case during beacon transmission, connection establishment, and robust communication.
As a solution to this problem, openwifi can be fully controlled only if communicating with APs/clients instantiated using hostapd/wpa_supplicant userspace programs respectively.
For hostapd program, 802.11b rates can be suppressed using configuration commands (i.e. supported_rates, basic_rates) and an example configuration file is provided (i.e. hostapd-openwifi.conf). One small caveat to this one comes from fullMAC Wi-Fi cards as they must implement the *NL80211_TXRATE_LEGACY* NetLink handler at the device driver level.
On the other hand, the wpa_supplicant program on the client side (commercial Wi-Fi dongle/board) cannot suppress 802.11b rates out of the box in 2.4GHz band, so there will be an issue when connecting openwifi (OFDM only). A patched wpa_supplicant should be used at the client side.
This section explains the porting work by showing the differences between openwifi and Analog Devices reference design. openwifi is based on 2019_R1 of [HDL Reference Designs](https://github.com/analogdevicesinc/hdl).
- The address/interrupts of FPGA blocks hooked to the ARM bus should be put/aligned to the devicetree file openwifi/kernel_boot/boards/zc706_fmcs2/devicetree.dts. Linux will parse the devicetree.dtb when booting to know information of attached device (FPGA blocks in our case).
- We use dtc command to get devicetree.dts converted from devicetree.dtb in [Analog Devices Linux image](https://wiki.analog.com/resources/tools-software/linux-software/zynq_images), then do modification according to what we have added/modified to the reference design.
- Please learn the script in [[Build openwifi Linux img from scratch](#Build-openwifi-Linux-img-from-scratch)] to understand how we generate devicetree.dtb, BOOT.BIN and Linux kernel uImage and put them together to build the full SD card image.
- Demo [[youtube](https://youtu.be/NpjEaszd5u4)], [[link for CHN user](https://www.zhihu.com/zvideo/1280659393378041856)]
- FOSDEM2020 [[youtube](https://youtu.be/Mq48cGthk7M)], [[link for CHN user](https://www.zhihu.com/zvideo/1280673506397425664)]
- Low latency for gaming and introduction [[youtube](https://youtu.be/Notn9X482LI)], [[link for CHN user](https://www.zhihu.com/zvideo/1273823153371385856)]
- CSI (Channel State Information) [[twitter](https://twitter.com/i/status/1314207380561780738)], [[link for CHN user](https://www.zhihu.com/zvideo/1297662571618148352)]
- FOSDEM2021 [[Flash back](https://twitter.com/jxjputaoshu/status/1358462741703491584?s=20)], [[link for CHN user](https://www.zhihu.com/zvideo/1340748826311974912)]; [[Presentation](https://mirror.as35701.net/video.fosdem.org/2021/D.radio/fsr_openwifi_opensource_wifi_chip.webm)], [[link for CHN user](https://www.zhihu.com/zvideo/1345036055104360448)]
- [openwifi: a free and open-source IEEE802.11 SDR implementation on SoC](https://www.orca-project.eu/wp-content/uploads/sites/4/2020/03/openwifi-vtc-antwerp-PID1249076.pdf)
- [IEEE 802.11 CSI randomization to preserve location privacy: An empirical evaluation in different scenarios](https://www.sciencedirect.com/science/article/abs/pii/S138912862100102X)
This project is available as open source under the terms of the AGPL 3.0 Or later. However, some elements are being licensed under GPL 2-0 or later and BSD 3 license . For accurate information, please check individual files.
