# ** IMPORTANT NOTICE **
## New release features
### v2.0.0
1. Optimized memory distribution and usage, with an increased available memory of **70 KB**, up by approximately **20 KB** compared to the previous SDK;
2. Optimized protocol libraries, including the lwIP, ESPCONN, mbedTLS, OpenSSL and MQTT;
3. Optimized Wi-Fi functionality with enhanced reliability, and added support for active/passive scanning;
4. Updated boot loader to version 1.7 with increased stability;
5. Added support for the 64-Mbit and 128-Mbit SPI flash;
6. Added 5 new demos, i.e. websocket demo, Wi-Fi station machine demo, openssl server demo, openssl client demo and mqtt demo.

For detail, you can refer to [v2.0.0](https://github.com/espressif/ESP8266_RTOS_SDK/releases/tag/v2.0.0) release notes.

## About this repository
A new branching model is applied to this repository, which consists of a master branch and release branches.

### 1. Master branch
The master branch is an integration branch where bug fixes/features are gathered for compiling and functional testing.

### 2. Release branch
The release branch is where releases are maintained and hot fixes (with names like *release/v2.x.x*) are added.
Please ensure that all your production-related work are tracked with the release branches.

With this new model, we can push out bug fixes more quickly and achieve simpler maintenance.

## Roadmap
*ESP8266_RTOS_SDK*'s framework is quite outdated and different from the current *[esp-idf](https://github.com/espressif/esp-idf)* and we are planning to migrate *ESP8266_RTOS_SDK* to *esp-idf* eventually after *v2.0.0*.

However, we will firstly provide a new version of ESP8266 SDK (*ESP8266_RTOS_SDK v3.0*), which shares the same framework with *esp-idf* (esp-idf style), as a work-around, because the multi-CPU architecture is not supported by *esp-idf* for the time being.

Actions to be taken for *ESP8266_RTOS_SDK v3.0* include the following items:

1. Modify the framework to esp-idf style
2. Restructure some core libraries including Wi-Fi libraries and libmain
3. Update some third-party libraries including FreeRTOS, lwIP, mbedTLS, noPoll, libcoap, SPIFFS, cJSON, wolfSSL, etc.
4. Update some drivers
5. Others

---

## Requirements

Both the xcc and gcc compilers can be used to compile the project. However, it is recommended that the gcc compiler be used.

For more information about the gcc compiler, please refer to [esp-open-sdk](https://github.com/pfalcon/esp-open-sdk).

## Compiling

1. Clone *ESP8266_RTOS_SDK*, i.e., to `~/ESP8266_RTOS_SDK`.

```
    $git clone https://github.com/espressif/ESP8266_RTOS_SDK.git
```

2. Modify *gen_misc.sh* or *gen_misc.bat*:

    * For Linux:
    ```
    $export SDK_PATH=~/ESP8266_RTOS_SDK
    $export BIN_PATH=~/ESP8266_BIN
    ```
    * For Windows:
    ```
    set SDK_PATH=/c/ESP8266_RTOS_SDK
    set BIN_PATH=/c/ESP8266_BIN
    ```

    You can use *ESP8266_RTOS_SDK/examples/project_template* to start your project, which can be copied anywhere, i.e., to `~/workspace/project_template`.

3. Generate bins:
    * For Linux:

    ```
    ./gen_misc.sh
    ```
    * For Windows:

    ```
    gen_misc.bat
    ```

## Downloading

1. *eagle.app.v6.flash.bin* should be downloaded to the address of *0x00000* in the flash.

2. *eagle.app.v6.irom0text.bin* should be downloaded to the address of *0x40000* in the flash.

3. *blank.bin* should be downloaded to the address of *0x7E000* in the flash.