BlOS chip includes: power-on self-test, interrupt routine, system setup, self-test program.
1. Interrupt the routine
The BIOS interrupt routine is the BIOS interrupt service program. It is a programmable interface between the software and hardware of the microcomputer system, which is used to connect the function of the program software with the realization of the microcomputer hardware.
2. System Settings
The microcomputer component configuration is placed in a readable CMOS RAM chip, and when not connected to the mains or the laptop has no battery, the CMOS supplies power to the CMOS through a backup battery to maintain the information in it.
3. Power-on self-test
After the microcomputer is powered On, the system will have a process of checking the various internal devices, which is done by a program commonly called POST(Power On Self Test). This is also a function of the BIOS.
4. Self-test procedure
After the completion of the POST self-test, the ROM BIOS will search the floppy disk drive and CDROM, network server and other valid boot drives in accordance with the startup order of the system CMOS Settings, read the operating system boot record, and then the system control to the boot record, by the boot record to complete the system boot.