What Is a Boot Loader?

Booting is a method often used by computers to start typing. After the computer is started, a small amount of instructions and data are input by the device, and then they are input into other programs. This process is called booting. The boot program in the microcomputer can guide the program and data entered by the user through the keyboard into the random access memory.

The boot loader is located at

Early programmable commercial computers, such as UNIVAC I and IBM 701, contained instructions to perform complete input and output operations. The same hardware logic can be used to load the contents of punch cards, or other input media, such as magnetic drums or magnetic tapes. These boot programs can be started by pressing keys. The IBM701 computer has a "Load" button, which can read the first 36 bits of the punch card into the main memory. The left 18-bit halfword is executed as an instruction and is usually used to read additional words into memory. The bootloader that is subsequently loaded is executed, which in turn does not require more manual operation to load a larger program from the medium into memory. The computer then jumps to memory location 001 and reads the first instruction stored. The first instruction is generally the same: move the information of the first 80 memory locations to a collection area (punched cards 2, 3, 4 ...). Once the information has been moved to these areas, the machine jumps to position 080 (reading a card), then the next card will be read and the relevant information will be processed. Other IBM computers of the same period had similar characteristics. The IBM 1401 system uses a card reader to load a program from a punch card. The 80 characters stored in the punch card are read into memory addresses 001 ~ 080. ^[2]

A boot device is a device from which the operating system can be loaded. Modern computer

Modern smartphones have an operating system. The system needs to be booted by a boot loader before booting. When the phone starts, the baseband performs initialization and then boots the system kernel until the system starts. Smartphone manufacturers usually lock the phone's boot loader when they leave the factory to prevent users from accidentally damaging the system files and causing the phone to malfunction. Some manufacturers will issue a boot loader unlock code to developers or ordinary users. This usually requires many steps. Applying, locking the boot loader can partially prevent the damage caused by malicious programs to the phone. Some users or developers will unlock the boot oader to obtain more functions and permissions, which usually brings risks of use. ^[2]