SDK Introduction

Overview

The SDK consists of the following three parts:

SDK
  ├── component                   Components such as FreeRTOS, SoC, mbed API, Wi-Fi, network, etc.
  ├── example                     Application examples, including audio, network, ota, usb, peripherals, etc.
  ├── tools                       Tools
  └── cmake                       Compilation abstraction layer

component

This directory contains the core functional components of the SDK, which are called by upper-layer applications. Common components are listed in the following table:

Item	Description
at_cmd	AT command support module
audio	Audio codec driver, supports: alc5616/alc5640/alc5651/alc5660/alc5679/alc5680/sgtl5000
bluetooth	Bluetooth protocol stack source code and related library files
file_system	File system implementation, includes: fatfs, littlefs, ftl, kv, vfs, etc.
lwip	LWIP protocol stack APIs and source code
network	Network protocol support, includes: cJSON CoAP DHCP HTTP/2 HTTP Client (httpc) HTTP Server (httpd) mDNS MQTT Ping iPerf SNTP WebSocket XML
os	FreeRTOS real-time operating system source code and OS APIs wrapper layer implementation
soc	SoC-related core modules, includes: app: System monitoring and Shell tools loader: Bootloader and GDB Loader cmsis: Arm header files defining CPU registers and basic operation APIs cmsis-dsp: Arm CMSIS-DSP digital signal processing library fwlib: Low-level drivers such as Audio Codec, SPORTS, UART, I2C, SPI, Timer, PWM, etc. img3: Trustzone support (may not be enabled) hal: Mbed APIs encapsulated based on Raw APIs main: main program entry misc: Other miscellaneous functions such as crashdump, OTA, PMU, etc. project: entry of build and configure swlib: Standard software library functions provided by ROM, such as _memcpy, _memcmp, etc. usrcfg: User-defined configuration files
ssl	Secure communication protocol stack, implemented based on mbed TLS
usb	USB class drivers and verification code
utils	Utility modules, includes: IPC (Inter-Processor Communication) Ringbuffer Unit Test Framework
wifi	Wi-Fi functional module, provides the following interfaces: Wi-Fi NIC mode: Used as a traditional Wi-Fi card R-mesh: Realtek Wi-Fi Mesh CSI: Wi-Fi sensing KVR: Wi-Fi roaming WPS: Wi-Fi Protected Setup MCC: Wi-Fi multi-channel coexistence Promisc: Wi-Fi promiscuous mode, capable of receiving all packets on current channel Fast connect: Rapid connection after Wi-Fi restart

Under the soc directory, each SoC has a main subdirectory, which serves as the main program entry point for that SoC. As an SoC may contain multiple MCUs, each MCU is assigned its own independent subdirectory.

component/soc/xxx/main
  ├── {mcu1}/                           Private main program directory for each MCU
  └── {mcu2}/                           Private main program directory for each MCU
     ├── inc/                           Header files (e.g., ``FreeRTOSConfig.h``, ``build_info.h``)
     └── src/                           Main program source code

Under the soc directory, each SoC has a project subdirectory, including Kconfig, CMake and layout files, which serves as the compilation entry point for that SoC. For each MCU within the SoC, there is a corresponding project_xx subdirectory containing linker scripts, as well as CMake configuration files for building the Bootloader and Application Image.

component/soc/xxx/project
  ├── project_{mcu1}/                   Private configuration directory for each MCU
  └── project_{mcu2}/                   Private configuration directory for each MCU; there will be multiple directories if the SoC contains multiple MCUs
     ├── ld/                            Linker scripts
     ├── lib/                           Library files
     └── make/                          CMake scripts used for compiling images

tools

This directory contains tools required during IC development.

Item	Description
TraceTool	Used for printing logs and sending commands Trace Tool
ImageTool	Used for downloading firmware Image Tool
DownloadServer	Socket-based OTA server program
DownloadServer (HTTP)	HTTP-based OTA server program
iperf	Used for Wi-Fi throughput testing
littlefs	Generates the littlefs file system
meta_tools	VS Code extension SDK-side adaptation toolset

Critical Header Files

The following table lists some key header files in the SDK and their descriptions:

Item	Description	Location
basic_types.h	RTK_SUCCESS/RTK_FAIL TRUE/FALSE ENABLE/DISABLE ON/OFF NULL u8/u16/u32/u64 BOOL BIT x …	component/soc/`amebaxxx`/fwlib/include
section_config.h	Definitions of various sections in the linker script: BOOT_RAM_DATA_SECTION IMAGE2_RAM_TEXT_SECTION …
ameba_soc.h	Provides Raw APIs for low-level drivers (recommended to use) Compared to mbed APIs, Raw APIs offer more flexible, rich, and efficient hardware configuration interfaces
mbed API headers	High-level encapsulation interfaces based on Raw APIs, providing relatively simplified functionality	component/soc/`amebaxxx`/hal

SDK License

Layer	Item	Version	License
Application	cJSON	n/a	MIT License https://github.com/DaveGamble/cJSON
NetWork	Lwip	v2.1.2	BSD License https://savannah.nongnu.org/projects/lwip
	GmSSL	v3.1.1	Apache-2.0 https://github.com/guanzhi/GmSSL
	mbedTLS	v3.6.2 v3.6.5	Apache-2.0 https://tls.mbed.org
Wi-Fi	wpa_supplicant	n/a	BSD License https://w1.fi/wpa_supplicant https://w1.fi/releases https://w1.fi/cgit/hostap/plain/wpa_supplicant/README
BT	LC3 Codec (BT audio codec lib)	n/a	Apache-2.0 http://www.apache.org/licenses/LICENSE-2.0
	SBC Codec (BT audio codec lib)	n/a	Apache-2.0 http://www.apache.org/licenses/LICENSE-2.0
	AES-CMAC	n/a	No License, free to use https://tools.ietf.org/html/rfc4493#appendix-A
	CCMS	n/a	Apache-2.0 http://www.apache.org/licenses/LICENSE-2.0 https://tls.mbed.org
	ECC (Kenneth MacKay)	n/a	BSD 2-Clause License https://github.com/kmackay/micro-ecc
	SHA256 (Colin Percival)	n/a	BSD 2-Clause License
File System	FatFs	n/a	BSD Licenses https://elm-chan.org/fsw/ff/
File System	LittleFS	n/a	BSD 3-Clause License https://github.com/littlefs-project/littlefs
OS	FreeRTOS	v10.2.1 v10.4.3 v10.5.1	MIT License https://www.freertos.org/
Audio	Audio effect	n/a	For audio effects Apache-2.0
	sonic	n/a	For audio speed Apache-2.0
	FLAC (Free Lossless Audio Codec) decoder	n/a	For decoding FLAC v2 or any later version LGPL
	haac	n/a	For decoding haac The contents of this file, and the files included with this file, are subject to the current version of the RealNetworks Public Source License Version 1.0 (the “RPSL”) unless you have licensed the file under the RealNetworks Community Source License Version 1.0 (the “RCSL”), in which case the RCSL will apply.
	gsm610	v1.0.19	For playing sound in ekho Any use of this software is permitted provided that this notice is not removed and that neither the authors nor the Technische Universitaet Berlin are deemed to have made any representations as to the suitability of this software for any purpose nor are held responsible for any defects of this software.
	libopus	n/a	For decode opus Contributions to the collaboration shall not be considered confidential. Each contributor represents and warrants that it has the right and authority to license copyright in its contributions to the collaboration. Each contributor agrees to license the copyright in the contributions under the Modified (2-clause or 3-clause) BSD License or the Clear BSD License. Please see the IPR statements submitted to the IETF for the complete patent licensing details: Xiph.Org Foundation: https://datatracker.ietf.org/ipr/1524/ Microsoft Corporation: https://datatracker.ietf.org/ipr/1914/ Skype Limited: https://datatracker.ietf.org/ipr/1602/ Broadcom Corporation: https://datatracker.ietf.org/ipr/1526/
	speexdsp	v1.2.1	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS` AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	tremolo	v0.07	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS` AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Ui	lvgl	v8.3 v9.3	MIT license Copyright(c) 2021 LVGL Kft
	jpeg	v62	libjpeg-turbo is covered by three compatible BSD-style open source licenses: The IJG (Independent JPEG Group) License, which is listed in [README.ijg](README.ijg). This license applies to the libjpeg API library and associated programs (any code inherited from libjpeg, and any modifications to that code). The Modified (3-clause) BSD License, which is listed below: This license covers the TurboJPEG API library and associated programs. The zlib License, which is listed below: This license is a subset of the other two, and it covers the libjpeg-turbo SIMD extensions.
	png	v1.6.34	libpng License
	zlib	v1.2.11	zlib License
AIVoice	tflite_micro	n/a	Apache-2.0 https://github.com/tensorflow/tflite-micro