BIOS.pptx

BIOS.pptx

• 2.
  What is Bios? TheBIOSisboot firmware, designed to be the first code run by aPCwhen powered on. The initial function of the BIOSis to identify, test, and initialize system devices suchasthe video display card, hard disk, floppy disk and other hardware. TheBIOSsets the machine hardware into aknown state, sothat software stored on compatible media canbe loaded, executed, and given control of thePC.
• 3.
  Bios as interface betweenOS and Hardware
• 4.
  The BIOS ina PC comes from three possible sources: • Motherboard ROM • Adapter card ROM(such asthat found on avideo card) • Loaded into RAMfrom disk(device drivers)
• 5.
  Motherboard Bios All motherboardsmust have aspecial chip containing software called the ROMBIOS.ThisROMchip contains the startup programs and drivers used to get the system running and act as the interface to the basic hardware in the system. When you turn on asystem, the power on self test (POST)in the BIOSalso tests the major components in the system.Additionally, you can run asetup program to store system configuration data in the CMOSmemory, which is powered by abattery on the motherboard. ThisCMOSRAMis often called NVRAM (nonvolatile RAM) because it runs on about 1 millionth of an amp of electrical current and can store data for years when powered by atiny lithium battery.
• 6.
  Functions of Bios
• 7.
  ThePOSTtests your computer'sprocessor, memory, chipset, video adapter, disk controllers, disk drives, keyboard, andother crucial components. POST (power on self test).
• 8.
  Setup Thesystem configuration andsetup program is usually a menu-driven program activated by pressing aspecial key during the POST ,and it enables you to configurethe motherboard and chipset settings along with the date and time, passwords,disk drives, and other basicsystem settings. Youalso can control the power-management settings and boot-drive sequence from the BIOSSetup, and on some systems, you can also configure CPU timing and clock-multiplier settings.
• 9.
  Setup Screen
• 10.
  Bootstrap loader Aroutine thatreads the first physical sector of various disk drives looking for avalid master boot record (MBR). If one meeting certain minimum criteria (ending in thesignature bytes 55AAh) is found, the code within isexecuted. TheMBRprogram code then continues the boot process by reading the first physical sector of the bootable volume, which is the start of the volume boot record(VBR).
• 11.
  Types of Bios •Amibios • Awardbios • Flashbios
• 12.
  A mibios
• 13.
  Awardbios
• 14.
  Flashbios
• 15.
  CMOS Setup S pecifications
• 16.
  Typical BIOS SetupMenus • Maintenance • Main • Advanced • Security • Power • Boot • Exit
• 17.
  Main Allocatesresourcesfor hardware components.
• 18.
  A dvanced Specifies advancedfeatures available through thechipset.
• 19.
  Power Specifies power managementfeatures.
• 20.
  B oot Specifies bootoptions and power supply controls.
• 21.
  E xit Savesor discardschanges to the setup program options.
• 22.
  Setup Configuration
• 23.
  Common manufacturers • American Megatrends • InsydeSoftware • Phoenix Technologies • Byosoft