update readme

README.md

@@ -4,12 +4,7 @@ kflash_gui
 Cross platform GUI wrapper for [kflash.py](https://github.com/sipeed/kflash.py.git) (download(/burn) tool for k210)
 
 
-|  |  |
-| -| -|
-| ![](kflash_gui_data/assets/screenshot_1.png) | ![](kflash_gui_data/assets/screenshot_2.png) |
-| ![](kflash_gui_data/assets/screenshot_download.png) | ![](kflash_gui_data/assets/screenshot_download_en.png) |
-| ![](kflash_gui_data/assets/screenshot_en.png) | ![](kflash_gui_data/assets/screenshot_file.png) |
-
+<img src="kflash_gui_data/assets/screenshot_1.2.1.png" width=500px/>
 
 ## Features
 
@@ -23,6 +18,16 @@ Cross platform GUI wrapper for [kflash.py](https://github.com/sipeed/kflash.py.g
 * Download(/burn) progress and speed display
 * Cancel download support
 
+
+## Screenshots
+
+| ![](kflash_gui_data/assets/screenshot_1.png) | ![](kflash_gui_data/assets/screenshot_2.png) |
+| -| -|
+| ![](kflash_gui_data/assets/screenshot_download.png) | ![](kflash_gui_data/assets/screenshot_download_en.png) |
+| ![](kflash_gui_data/assets/screenshot_en.png) | ![](kflash_gui_data/assets/screenshot_file.png) |
+
+
+
 ## Usage
 
 * Download bin file (`kflash_gui_v*.*`)  [here](https://github.com/sipeed/kflash_gui/releases)
@@ -31,7 +36,7 @@ Cross platform GUI wrapper for [kflash.py](https://github.com/sipeed/kflash.py.g
 
 * you can create your own shortcut by yourself； If `Linux`， edit the path in `kflash_gui.desktop`, then copy this file to `/usr/share/application` folder with administrator, and finally you can find `kflash_gui` app in the system menu
 
-* Select `bin` file or `kfpkg` file
+* Select `bin` file or `kfpkg` file， set address to `0x0000` if file is firmware, and set `Prefix` checkbox to enable add parity prefix
 * Select board
 * Select where firmware flash to, `Flash` or `SRAM`
 * Select serial port
@@ -47,9 +52,7 @@ Cross platform GUI wrapper for [kflash.py](https://github.com/sipeed/kflash.py.g
 * Check if serial occupied by other software
 * Replug in USB cable and try again
 
-## How To Pack `kfpkg`
-
-`bin` just can be downloaded to address at `0x000000` of `Flash`, you need to create your own `kfpkg` file if you need to specify an address, such as downloading a model file, and download it.
+## How `kfpkg` coms from
 
 Refer here: [blog.sipeed.com/p/390.html](http://blog.sipeed.com/p/390.html)
 
@@ -75,7 +78,7 @@ Refer here: [blog.sipeed.com/p/390.html](http://blog.sipeed.com/p/390.html)
 * 
 * 可以自行建快捷方式或者固定到开始页面或者固定要任务栏方便使用； 如果是 `Linux`， 可以修改 `kflash_gui.desktop` 里面的路径， 然后用管理员身份复制到`/usr/share/application` 目录， 然后就可以在系统菜单里面找到`kflash_gui`的图标了，点击即可打开
 
-* 选择 `bin` 文件或者 `kfpkg` 文件
+* 选择 `bin` 文件或者 `kfpkg` 文件， 如果是`bin`文件需要指定地址，如果是固件需要指定`0x0000`地址并且选择`校验头`
 * 选择开发板
 * 选择烧录到开发板的哪个位置 `Flash`（速度慢但是重新上电还可运行） 或者 `SRAM`（`RAM`中运行，下载快断电丢失程序）
 * 选择串口
@@ -92,7 +95,7 @@ Refer here: [blog.sipeed.com/p/390.html](http://blog.sipeed.com/p/390.html)
 * 串口是否被其它软件占用
 * 串口是否出了奇怪的问题，拔掉电脑连接到板子的线重新插一下试试
 
-## 如何打包 `kfpkg`
+## 如何手动打包 `kfpkg`
 
 `bin` 文件只能下载到 `Flash` 地址 `0x000000`, 如果需要指定地址，比如下载模型文件，则需要创建 `kfpkg` 文件然后下载