编写适合自己嵌入式系统的Boot Loader ！-Preparation for their embedded system Boot Loader!

这个是stm32 使用boot loader从sd卡更新的教程，不是源代码。详细介绍了更新的全过程。(This is the tutorial that STM32 uses boot loader to update from the SD card, not the source code. The whole process of updating is introduced in detail.)