RTL8720F EVB

Tags: chip:rtl8720f arch:arm vendor:realtek

Todo

Add a photo of the RTL8720F EVB board here as rtl8720f_evb.png in this directory, referenced with a .. figure:: directive.

The RTL8720F EVB is a Realtek RTL8720F (dual-core Wi-Fi Host Controller) evaluation board. NuttX runs on the KM4TZ (Cortex-M33, secure world) application core as the Wi-Fi host; the KM4NS network processor runs the prebuilt vendor Wi-Fi firmware. See the RTL8720F chip documentation for the SoC architecture, memory map and vendor-SDK dependency.

Features

  • RTL8720F dual-core Wi-Fi Host Controller (KM4TZ Cortex-M33 secure host + KM4NS NP)

  • 2.4 GHz Wi-Fi (station and SoftAP)

  • SPI NOR flash (shared with the NP, XIP)

  • LOG-UART console

Supported in this NuttX port:

  • NSH shell over the LOG-UART console (NuttX owns LOG-UART RX directly; the NP shell is disabled)

  • littlefs persistent storage mounted at /data (a dedicated SPI NOR flash partition), backing the Wi-Fi key-value store

  • Wi-Fi station and SoftAP through the wapi tool

  • DHCP client (STA) and DHCP server (SoftAP)

Note

The Wi-Fi MAC/PHY is driven by the prebuilt vendor firmware on the KM4NS network processor. NuttX is the Wi-Fi host and exchanges frames with the NP over the on-chip IPC transport; see the chip documentation.

Buttons and LEDs

This NuttX port does not wire any user buttons or LEDs.

Configurations

$ ./tools/configure.sh rtl8720f_evb:<config-name>

nsh

Networking-enabled NSH with littlefs at /data and the wapi Wi-Fi tool. The console is the LOG-UART at 1500000 8N1 (the rate is configured by the bootloader and inherited by NuttX). The Wi-Fi examples below are available from this configuration.

Wi-Fi

Station (connect to an AP):

nsh> wapi psk    wlan0 <password> 3
nsh> wapi essid  wlan0 <ssid> 1
nsh> renew wlan0

SoftAP (become an access point, with a DHCP server for clients):

nsh> wapi mode   wlan0 3
nsh> wapi psk    wlan0 <password> 3
nsh> wapi essid  wlan0 <ssid> 1
nsh> ifconfig    wlan0 192.168.4.1 netmask 255.255.255.0
nsh> dhcpd_start wlan0

Stop the SoftAP with wapi essid wlan0 <ssid> 0.

Building and Flashing

The build auto-fetches the Realtek ameba-rtos SDK on first use and a Realtek arm-none-eabi toolchain must be on PATH; see the chip documentation for both.

$ ./tools/configure.sh rtl8720f_evb:nsh
$ make

This produces nuttx/app.bin (the NuttX KM4TZ image2), boot.bin and the NP (KM4NS) image in the build directory.

After a successful build, flash via one of these methods:

CLI (Linux/macOS) — connect a USB-UART adapter (PL2303) and use the built-in make flash target:

$ make flash AMEBA_PORT=/dev/ttyUSB0

The baud rate defaults to 1500000; override with AMEBA_BAUD if needed.

GUI (Windows) — use the Realtek AmebaImageTool (AmebaImageTool.exe under tools/ameba/ImageTool/ in the SDK tree) to select boot.bin and app.bin.

See the Realtek Ameba ImageTool guide for the Windows GUI tool and download-mode entry (hold the download button / power-cycle with the UART_LOG_TX line asserted).

Serial console — after flashing, connect to the LOG-UART at 1500000 8N1:

$ picocom -b 1500000 /dev/ttyUSB0

Other tools: screen /dev/ttyUSB0 1500000 or minicom -b 1500000 -D /dev/ttyUSB0.

License Exceptions

This board depends on Realtek vendor code that is not part of NuttX and is subject to its own license:

  • The prebuilt KM4NS (NP) Wi-Fi firmware image and the Realtek ameba-rtos SDK libraries/headers linked into the image. See the SDK’s own license; the SDK is auto-fetched and is not redistributed in the NuttX tree.