什么是firmware?

      什么是firmware? 来看看英文维基百科吧：

  In electronic systems and computing, firmware is the combination of persistent memory and program code and data stored in it.^[1] Typical examples of devices containing firmware are embedded systems (such as traffic lights, consumer appliances, and digital watches), computers, computer peripherals, mobile phones, and digital cameras. The firmware contained in these devices provides the control program for the device. Firmware is held in non-volatile memory devices such as ROM, EPROM, orflash memory. Changing the firmware of a device may rarely or never be done during its economic lifetime; some firmware memory devices are permanently installed and cannot be changed after manufacture. Common reasons for updating firmware include fixing bugs or adding features to the device. This may require physically changing ROM integrated circuits^{[citation needed]}, or reprogramming flash memory with a special procedure.^[2] Firmware such as the ROM BIOS of a personal computer may contain only elementary basic functions of a device and may only provide services to higher-level software. Firmware such as the program of an embedded system may be the only program that will run on the system and provide all of its functions.

   Before integrated circuits, other firmware devices included a discrete semiconductor diode matrix. TheApollo guidance computer had firmware consisting of a specially manufactured core memory plane, called "core rope memory", where data were stored by physically threading wires through (1) or around (0) the core storing each data bit.^[3]

   Flashing (or flashing firmware^[4]) refers to the overwriting of existing firmware or data on ROM modules present in an electronic device with new data.^[4] This can be done to upgrade a device ^[5] or to change the provider of a service associated with the function of the device, such as changing from onemobile phone service provider to another or installing a new operating system. If firmware is upgradable, it's often done via a program from the provider (see below), and will often allow the old firmware to be saved before upgrading so it can be reverted to if the process fails, or the newer version was worse.

   再看看看中文资料：

   固件（firmware），台湾、港澳译作“韧体”，是一种嵌入在硬件设备中的软件。通常它是位于特殊应用集成电路（ASIC）或可编程逻辑器件（PLD）之中的闪存或EEPROM或PROM里，有的可以让用户更新。可以应用在非常广泛的电子产品中，从遥控器、计算器到电脑中的键盘、硬盘，甚至工业机器人中都可见到它的身影。

顾名思义，固件的所在是位于软件和硬件之间的。像软件一样，他是一个被计算机所运行的程序。然而它是对于硬件内部而言更加贴近以及更加重要的部份，而对于外在的世界而言较无重要的意义。

   我的理解： 固件是软件（程序）， 存储在硬件中。在手机进行刷机时， 刷的就是固件。 在机顶盒进行升级时， 刷的就是固件， 也就是机顶盒软件厂商发布的软件版本。