# QEMU(Tutorials of C-SKY )

## 1.Introduction

QEMU can simulate the kernel to run on different boards, freeing the dependence on the physical development board.The `SmartL_E802/` subdirectory contains part of the OpenHarmony kernel\_liteos\_m code verified by the Qemu C-SKY virtualization platform,you can simulate a single board based on the C-SKY architecture.

## 2.Setup Environment

   1. Set up the Compilation tool chain

      Tip: Users can also skip this step by using the following instructions directly to use the compiler configured in the default environment.

      To use the default environment, execute '3.Get source code' and then install the default compiler in the root directory by executing the following instructions.

         ```shell
         sh build/prebuilts_download.sh
         ```

      Optional compiler installation process:

      a) Create the `csky_toolchain` folder and enter it

         ```shell
         mkdir csky_toolchain && cd csky_toolchain
         ```

      b) Download  csky-elfabiv2-tools-x86_64-minilibc-20210423.tar.gz to `csky_toolchain`folder and unzip,download link: https://occ.t-head.cn/community/download?id=3885366095506644992

         ```shell
         wget https://occ-oss-prod.oss-cn-hangzhou.aliyuncs.com/resource/1356021/1619529111421/csky-elfabiv2-tools-x86_64-minilibc-20210423.tar.gz
         tar -xf csky-elfabiv2-tools-x86_64-minilibc-20210423.tar.gz
         ```

      c) Add the csky-elfabiv2 compilation tool chain to the environment variable (modify user_toolchain_xxx_path to your own installation path):

         ```shell
         vim ~/.bashrc
         export PATH=$PATH:user_toolchain_xxx_path/csky_toolchain/bin
         source ~/.bashrc
         ```

      d) Delete the default compiler path:

         change SmartL_E802\liteos_m\config.gni:

         ```c
         board_toolchain_path = "$ohos_root_path/prebuilts/gcc/linux-x86/csky/csky/bin"
         ```

         to

         ```c
         board_toolchain_path = ""
         ```

   2. Install qemu

      a) create `csky_qemu` folder and enter it

         ```shell
         mkdir csky_qemu && cd csky_qemu
         ```

      b) download csky-qemu-x86_64-Ubuntu-16.04-20210202-1445.tar.gz to `csky_qemu`folder and unzip,download link: https://occ.t-head.cn/community/download?id=636946310057951232

         ```shell
         wget https://occ-oss-prod.oss-cn-hangzhou.aliyuncs.com/resource/1356021/1612269502091/csky-qemu-x86_64-Ubuntu-16.04-20210202-1445.tar.gz
         tar -xf csky-qemu-x86_64-Ubuntu-16.04-20210202-1445.tar.gz
         ```

      c) Add qemu to the environment variable (modify user_qemu_xxx_path to your own installation path):

         ```shell
         vim ~/.bashrc
         export PATH=$PATH:user_qemu_xxx_path/csky-qemu/bin
         source ~/.bashrc
         ```

      d) Installation dependencies

         ```shell
         ldd qemu_installation_path/bin/qemu-system-cskyv2
         ```

         According to the execution result of ldd, install the missing dependent libraries

         (Annotation: For more installation instructions, please refer to the following link: https://occ.t-head.cn/community/download?id=636946310057951232)

## 3.Get source code

[code acquisition ](https://gitee.com/openharmony/docs/blob/master/en/device-dev/get-code/sourcecode-acquire.md)

Hint : You can use the `repo` command to get the source code.

## 4.Source buildding

   1. Execute the hb set command and select the project`qemu_csky_mini_system_demo`.

   2. Execute the hb clean && hb build command to build the executable file that produces `OHOS_Image`.

      ```shell
      hb set
      hb clean && hb build
      ```

   3. After the buildding is complete,the corresponding executable file is in the home directory:

      ```
      out/SmartL_E802/qemu_csky_mini_system_demo/
      ```

## 5.Run the image in Qemu

   1. Run qemu(Don't cooperate with GDB)

      ```shell
      ./qemu-run
      ```

   2. Run qemu(Cooperate with GDB)

      a) Start the GDB server and wait for the connection

         ```shell
         ./qemu-run -g
         ```

      b) Create a new terminal and use GDB to connect to qemu

         ```shell
         csky-abiv2-elf-gdb out/SmartL_E802/qemu_csky_mini_system_demo/OHOS_Image -ex "target remote localhost:1234"
         ```

   Annotation: The way to exit qemu : press ctrl and a,then release and press x.

# QEMU（C-SKY 教程）

## 1.简介

QEMU可以模拟内核运行在不同的单板，解除对物理开发板的依赖。`SmartL_E802/`子目录包含部分Qemu C-SKY虚拟化平台验证的OpenHarmony kernel\_liteos\_m的代码，通过它来模拟一个基于C-SKY架构的单板。

## 2.环境搭建

   1. 编译工具链安装

      提示：用户也可以直接使用下列指令来使用默认环境中配置好的编译器，跳过该步骤。

      若要使用默认环境请先执行 '3.获取源码' ，然后在根目录下执行下列指令安装默认编译器。

         ```shell
         sh build/prebuilts_download.sh
         ```

      可选的编译器安装流程：

      a) 创建`csky_toolchain`文件夹并进入

         ```shell
         mkdir csky_toolchain && cd csky_toolchain
         ```

      b) 下载csky-elfabiv2-tools-x86_64-minilibc-20210423.tar.gz 到`csky_toolchain`文件夹并解压，下载地址：https://occ.t-head.cn/community/download?id=3885366095506644992

         ```shell
         wget https://occ-oss-prod.oss-cn-hangzhou.aliyuncs.com/resource/1356021/1619529111421/csky-elfabiv2-tools-x86_64-minilibc-20210423.tar.gz
         tar -xf csky-elfabiv2-tools-x86_64-minilibc-20210423.tar.gz
         ```

      c) 将csky-elfabiv2编译工具链加入环境变量(将user_toolchain_xxx_path修改为自己的安装路径)：

         ```shell
         vim ~/.bashrc
         export PATH=$PATH:user_toolchain_xxx_path/csky_toolchain/bin
         source ~/.bashrc
         ```

      d) 删除默认的编译器路径：

         修改SmartL_E802\liteos_m\config.gni：

         ```c
         board_toolchain_path = "$ohos_root_path/prebuilts/gcc/linux-x86/csky/csky/bin"
         ```

         改为

         ```c
         board_toolchain_path = ""
         ```

   2. qemu安装

      a) 创建`csky_qemu`文件夹并进入

         ```shell
         mkdir csky_qemu && cd csky_qemu
         ```

      b) 下载csky-qemu-x86_64-Ubuntu-16.04-20210202-1445.tar.gz到`csky_qemu`文件夹下并解压，下载地址：https://occ.t-head.cn/community/download?id=636946310057951232

         ```shell
         wget https://occ-oss-prod.oss-cn-hangzhou.aliyuncs.com/resource/1356021/1612269502091/csky-qemu-x86_64-Ubuntu-16.04-20210202-1445.tar.gz
         tar -xf csky-qemu-x86_64-Ubuntu-16.04-20210202-1445.tar.gz
         ```

      c) 将qemu加入环境变量(将user_qemu_xxx_path修改为自己的安装路径):

         ```shell
         vim ~/.bashrc
         export PATH=$PATH:user_qemu_xxx_path/csky-qemu/bin
         source ~/.bashrc
         ```

      d) 安装依赖

         ```shell
         ldd qemu_installation_path/bin/qemu-system-cskyv2
         ```

         根据ldd执行结果，安装缺少的依赖库

         (注：更多使用安装指导，请参考官方指南：https://occ.t-head.cn/community/download?id=636946310057951232)

## 3.获取源码

[代码获取](https://gitee.com/openharmony/docs/blob/master/zh-cn/device-dev/get-code/sourcecode-acquire.md)

提示: 可以使用 `repo` 命令来获取源码。

## 4.源码构建

   1. 执行hb set命令并选择项目`qemu_csky_mini_system_demo`。

   2. 执行hb clean && hb build命令构建产生 `OHOS_Image` 的可执行文件。

      ```shell
      hb set
      hb clean && hb build
      ```

   3. 在构建完成之后，对应的可执行文件在主目录下：

      ```
      out/SmartL_E802/qemu_csky_mini_system_demo/
      ```

## 5.在Qemu中运行镜像

   1. 启动qemu(不配合GDB)

      ```shell
      ./qemu-run
      ```

   2. 启动qemu(配合GDB)

      a) 启动GDB服务器，等待连接

         ```shell
         ./qemu-run -g
         ```

      b) 新建终端并使用GDB连接qemu

         ```shell
         csky-abiv2-elf-gdb out/SmartL_E802/qemu_csky_mini_system_demo/OHOS_Image -ex "target remote localhost:1234"
         ```

   注：qemu退出方式为：按下ctrl加a键，然后松开再按下x键。