Extension method and extension device of boot loader and electronic equipment

The invention provides a boot loader extension method and device and electronic equipment, and the method comprises the steps: selecting an address field with a first preset address length from an application program address field, and obtaining a first extension address field; selecting an address field with a second predetermined address length from the application program address field to obtain a second extended address field; acquiring an initial address and a termination address of the first extended address field, writing the initial address and the termination address of the first extended address field into the second boot loader, and storing the first boot loader exceeding the capacity of the address field of the first boot loader into the first extended address field; and acquiring a start address and a stop address of the second extended address field, writing the start address and the stop address of the second extended address field into the first boot loader, and storing the second boot loader