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 and advanced feature 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.
**Note**: If you have symbol or version error while loadng the driver, it could be because the kernel in the SD card image is too old. In this case, you need to follow [[Build openwifi Linux img from scratch](#Build-openwifi-Linux-img-from-scratch)] to generate your new SD card image.
- 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.
