Flash存储器又称闪存，它结合了ROM和RAM的长处，不仅具备电子可擦除可编程（EEPROM）的性能，还可以快速读取数据（NVRAM的优势），使数据不会因为断电而丢失。U盘和MP3里用的就是这种存储器。在过去的20年里，嵌入式系统一直使用ROM（EPROM）作为它们的存储设备，然而近年来Flash全面代替了ROM（EPROM）在嵌入式系统中的地位，用作存储Bootloader以及操作系统或者程序代码-Flash memory also known as flash, it combines the strengths of ROM and ram, not only have the electronic erasable programming (EEPROM) performance, but also can quickly read data (NVRAM), so that the data is not lost due to power outages. This kind of memory is used in the U disk and MP3. In the past 20 years, embedded system has been using ROM (EPROM) as their storage devices. However, in recent years, flash instead of a comprehensive ROM (EPROM) position in embedded system, used for storage of bootloader and operating system or program code, or directly when the use of hard disk