1# RT-Thread # 2 3[中文页](README_zh.md) | 4 5[](https://github.com/RT-Thread/rt-thread/blob/master/LICENSE) 6[](https://github.com/RT-Thread/rt-thread/releases) 7[](https://travis-ci.org/RT-Thread/rt-thread) 8[](https://gitter.im/RT-Thread/rt-thread?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) 9[](https://github.com/RT-Thread/rt-thread/pulls) 10[](https://github.com/RT-Thread/rt-thread/pulls) 11 12RT-Thread is an open source IoT operating system from China, which has strong scalability: from a tiny kernel running on a tiny core, for example ARM Cortex-M0, or Cortex-M3/4/7, to a rich feature system running on MIPS32, ARM Cortex-A8, ARM Cortex-A9 DualCore etc. 13 14## Overview ## 15 16RT-Thread RTOS like a traditional real-time operating system. The kernel has real-time multi-task scheduling, semaphore, mutex, mail box, message queue, signal etc. However, it has three different things: 17 18* Device Driver; 19* Component; 20* Dyanmic Module 21 22The device driver is more like a driver framework, UART, IIC, SPI, SDIO, USB device/host, EMAC, MTD NAND etc. The developer can easily add low level driver and board configuration, then combined with the upper framework, he/she can use lots of features. 23 24The Component is a software concept upon RT-Thread kernel, for example a shell (finsh/msh shell), virtual file system (FAT, YAFFS, UFFS, ROM/RAM file system etc), TCP/IP protocol stack (lwIP), POSIX (thread) interface etc. One component must be a directory under RT-Thread/Components and one component can be descripted by a SConscript file (then be compiled and linked into the system). 25 26The Dyanmic Module, formerly named as User Applicaion (UA) is a dyanmic loaded module or library, it can be compiled standalone without Kernel. Each Dyanmic Module has its own object list to manage thread/semaphore/kernel object which was created or initialized inside this UA. More information about UA, please visit another [git repo](https://github.com/RT-Thread/rtthread-apps). 27 28## Board Support Package ## 29 30RT-Thread RTOS can support many architectures: 31 32* ARM Cortex-M0 33* ARM Cortex-M3/M4/7 34* ARM Cortex-R4 35* ARM Cortex-A8/A9 36* ARM920T/ARM926 etc 37* MIPS32 38* x86 39* Andes 40* C-Sky 41* RISC-V 42* PowerPC 43 44## License ## 45 46RT-Thread is Open Source software under the Apache License 2.0 since RT-Thread v3.1.1. License and copyright information can be found within the code. 47 48 /* 49 * Copyright (c) 2006-2018, RT-Thread Development Team 50 * 51 * SPDX-License-Identifier: Apache-2.0 52 */ 53 54Since 9th of September 2018, PRs submitted by the community may be merged into the main line only after signing the Contributor License Agreement(CLA). 55 56NOTE: 57 58RT-Thread using the Apache license v2.0 is only launched after the release of v3.1.1, and is still in preparation right now. 59 60## Usage ## 61 62RT-Thread RTOS uses [scons](http://www.scons.org) as building system. Therefore, please install scons and Python 2.7 firstly. 63So far, the RT-Thread scons building system support the command line compile or generate some IDE's project. There are some option varaibles in the scons building script (rtconfig.py): 64 65* ```CROSS_TOOL``` the compiler which you want to use, gcc/keil/iar. 66* ```EXEC_PATH``` the path of compiler. 67 68In SConstruct file: 69 70```RTT_ROOT``` This variable is the root directory of RT-Thread RTOS. If you build the porting in the bsp directory, you can use the default setting. Also, you can set the root directory in ```RTT_ROOT``` environment variable and not modify SConstruct files. 71 72When you set these variables correctly, you can use command: 73 74 scons 75 76under BSP directory to simplely compile RT-Thread RTOS. 77 78If you want to generate the IDE's project file, you can use command: 79 80 scons --target=mdk/mdk4/mdk5/iar/cb -s 81 82to generate the project file. 83 84NOTE: RT-Thread scons building system will tailor the system according to your rtconfig.h configuration header file. For example, if you disable the lwIP in the rtconfig.h by commenting the ```#define RT_USING_LWIP```, the generated project file should have no lwIP related files. 85 86## Contribution ## 87 88Please refer the contributors in the github. Thank all of RT-Thread Developers. 89