Bios ConfigurationBios ConfigurationBios ConfigurationBios Configuration

Mohd Saiful Rizal bin YusoffMohd Saiful Rizal bin YusoffHasani EnterpriseHasani Enterprise

OverviewOverview

In this chapter, you will learn toIn this chapter, you will learn to

Explain the function of BIOSExplain the function of BIOS

Distinguish among various CMOS setup utility Distinguish among various CMOS setup utility optionsoptions

Describe option ROM and device driversDescribe option ROM and device drivers

Troubleshoot the power-on self test (POST)Troubleshoot the power-on self test (POST)

We Need to TalkWe Need to Talk

Historical/ConceptualHistorical/Conceptual

Bridge IntroductionBridge Introduction

Data flows through the computerData flows through the computerBetween CPU and RAMBetween CPU and RAM

Between CPU and videoBetween CPU and video

Between CPU and other devicesBetween CPU and other devices

Bridges are used to connect the piecesBridges are used to connect the piecesNorthbridgeNorthbridge

Bridge closest to the CPU Bridge closest to the CPU

SouthbridgeSouthbridgeThe farther bridgeThe farther bridge

Northbridge & SouthbridgeNorthbridge & Southbridge

NorthbridgeNorthbridgeChip or chips that Chip or chips that connect the CPU to connect the CPU to video and/or memoryvideo and/or memory

SouthbridgeSouthbridgeHandles all of the Handles all of the inputs and outputs to inputs and outputs to the many devices in the many devices in the PCthe PC

• A A chipsetchipset is a set of Northbridge and is a set of Northbridge and Southbridge chips that work togetherSouthbridge chips that work together

Data FlowData FlowNorthbridge and SouthbridgeNorthbridge and Southbridgehave connectivity with all deviceshave connectivity with all devices

Not the same in all systemsNot the same in all systems

ChipsetChipset

NorthbridgeNorthbridge

SouthbridgeSouthbridge

Basic Input/Output System (BIOS)Basic Input/Output System (BIOS)

Bridges connect the devicesBridges connect the devicesBut without a program, they don’t know how But without a program, they don’t know how to communicateto communicate

A special kind of program is required to A special kind of program is required to enable the CPU to talk to other devicesenable the CPU to talk to other devices

A Flash ROM chip stores these programsA Flash ROM chip stores these programs

These programs are collectively known These programs are collectively known as the basic input/output service (BIOS)as the basic input/output service (BIOS)

Talking to the KeyboardTalking to the Keyboard

The keyboard talks to the external data The keyboard talks to the external data bus bus

Uses the Uses the keyboard controllerkeyboard controller chip (8042) chip (8042)

BIOSBIOS

Each program is called a Each program is called a serviceservice

Programs stored on Flash ROM chips are known Programs stored on Flash ROM chips are known as as firmwarefirmware

Programs stored on erasable media are called Programs stored on erasable media are called softwaresoftware

Keyboard Keyboard controller controller

chipchip

CMOSCMOS

Separate chip from ROM BIOSSeparate chip from ROM BIOS

Volatile (kept alive by battery)Volatile (kept alive by battery)

Stores only changeable data Stores only changeable data Not programsNot programs

Acts as clock to keep data currentActs as clock to keep data current

Customizable via SETUP programCustomizable via SETUP program

Often on SouthbridgeOften on Southbridge

BIOS vs. CMOSBIOS vs. CMOS

BIOSBIOSProgramsPrograms

Non-volatile (stays Non-volatile (stays same after power off)same after power off)

Can be changed by Can be changed by “flashing”“flashing”

Typically 64 K of Typically 64 K of programs (though programs (though Flash ROM is much Flash ROM is much bigger)bigger)

Often a separate chipOften a separate chip

CMOSCMOSDataData

Volatile (kept alive with Volatile (kept alive with battery)battery)

Changed via CMOS Changed via CMOS setupsetup

Typically 128 K of data Typically 128 K of data (though chip size is (though chip size is typically 64 K)typically 64 K)

Often on SouthbridgeOften on Southbridge

Updating CMOS Updating CMOS

• Updated via BIOS programUpdated via BIOS program• Three primary BIOS brandsThree primary BIOS brands

– American Megatrends (AMI), Award, PhoenixAmerican Megatrends (AMI), Award, Phoenix– To enter setup, press key combinationTo enter setup, press key combination

(may be Del, ESC, (may be Del, ESC, F1, F2, F1, F2, CTRL-ALT-ESC, CTRL-ALT-ESC, CTRL-ALT-INS, CTRL-ALT-INS, CTRL-ALT-Enter, CTRL-ALT-Enter, or CTRL-S)or CTRL-S)

CMOS Setup CMOS Setup

• Main menu Main menu – Access to all submenusAccess to all submenus

Standard CMOS FeaturesStandard CMOS Features

• Clock, hard drives, floppy drivesClock, hard drives, floppy drives

SoftMenu SetupSoftMenu Setup

Normally set to Default or Auto for allNormally set to Default or Auto for all

Advanced FeaturesAdvanced Features

POST, boot orderPOST, boot order

Power ManagementPower Management

Use to enable/disable power-saving Use to enable/disable power-saving featuresfeatures

PnP/PCIPnP/PCI

Rarely need to manipulate on today’s PCsRarely need to manipulate on today’s PCs

Set PasswordSet Password

Locks access to CMOS settingsLocks access to CMOS settingsPrevents non-techs from changing key settingsPrevents non-techs from changing key settings

Option ROM and Device DriversOption ROM and Device Drivers

BYOBBYOB

Computer makers could not predict all the new Computer makers could not predict all the new types of hardware types of hardware

Ways to Ways to bring your own BIOS bring your own BIOS (BYOB) were (BYOB) were invented:invented:

Option ROM Option ROM is a BIOS chip embedded on the adapter is a BIOS chip embedded on the adapter card itself – (i.e., video cards)card itself – (i.e., video cards)

Most new hardware devices use Most new hardware devices use device driversdevice drivers to tell to tell the BIOS how to talk to the CPUthe BIOS how to talk to the CPU

Most devices with onboard BIOS use it only for internal Most devices with onboard BIOS use it only for internal needs (needs (internal functioninternal function) and use a device driver to ) and use a device driver to talk to the CPUtalk to the CPU

Device Drivers Device Drivers

A A device driver device driver is a file that contains the is a file that contains the BIOS commands necessary to communicate BIOS commands necessary to communicate with the devices they supportwith the devices they support

Loaded into RAM when the system bootsLoaded into RAM when the system boots

All devices come with their own device All devices come with their own device driversdrivers

BIOS, BIOS, EverywhereBIOS, BIOS, Everywhere

All hardware needs a program to allow CPU All hardware needs a program to allow CPU to communicate with itto communicate with it

Could be on motherboard ROMCould be on motherboard ROM

Could be on PC card ROMCould be on PC card ROM

Could be loaded via a driverCould be loaded via a driver

Could be loaded into RAM at bootCould be loaded into RAM at boot

Power-On Self Test (POST)Power-On Self Test (POST)

CompTIA A+CompTIA A+TechnicianTechnician

IT TechnicianIT Technician

Power-On Self Test (POST) Power-On Self Test (POST)

The The power-on self test (POST) power-on self test (POST) is a special is a special program stored on the ROM chipprogram stored on the ROM chip

Initiated when the computer is turned on or is Initiated when the computer is turned on or is resetreset

Checks out the system every time the computer Checks out the system every time the computer bootsboots

Communicates errorsCommunicates errors

Beep codesBeep codes

Text errorsText errors

Beep Codes Beep Codes

If video is determined to be missing or faultyIf video is determined to be missing or faulty One long beep followed by three short beepsOne long beep followed by three short beeps

If everything checks outIf everything checks out One or two short beepsOne or two short beeps

If RAM is missing or faultyIf RAM is missing or faulty Buzzing noise that repeats until power turned offBuzzing noise that repeats until power turned off

More complicated beep codes may be found in More complicated beep codes may be found in legacy computerslegacy computers Check motherboard manual for meaningCheck motherboard manual for meaning

Text-Based Error MessageText-Based Error Message

POST Cards POST Cards

POST cards POST cards are devices that monitor POSTs and are devices that monitor POSTs and report on the hardware that may be causing report on the hardware that may be causing problemsproblems

Turn the PC off, plug in the card, Turn the PC off, plug in the card, and reboot and reboot

POST error codes do not fix the POST error codes do not fix the computer – they just tell you computer – they just tell you where to look where to look

If all else fails, replace the If all else fails, replace the motherboardmotherboard

The Boot Process The Boot Process

The CPU is the first component initialized The CPU is the first component initialized when the computer is turned onwhen the computer is turned on

It reads a special wire called It reads a special wire called power good power good once the power supply provides the proper once the power supply provides the proper voltage to the CPUvoltage to the CPU

Every CPU has a built-in memory address Every CPU has a built-in memory address with the first line of the POST program on with the first line of the POST program on the system ROMthe system ROM

The Boot Process The Boot Process

The last BIOS function called by POST is the The last BIOS function called by POST is the bootstrap loaderbootstrap loader

The bootstrap loader loads the operating The bootstrap loader loads the operating system from the boot sectorsystem from the boot sector

Searches the floppy, CD-ROM, or the hard drive Searches the floppy, CD-ROM, or the hard drive

Boot order set in CMOSBoot order set in CMOS

The bootstrap loader generates an error if it The bootstrap loader generates an error if it cannot find the boot sector on the bootable cannot find the boot sector on the bootable diskdisk

Losing CMOS SettingsLosing CMOS Settings

Common errorsCommon errors CMOS configuration mismatchCMOS configuration mismatch CMOS date/time not setCMOS date/time not set No boot device availableNo boot device available CMOS battery state lowCMOS battery state low

Common reasons for losing CMOS dataCommon reasons for losing CMOS data Jiggling the battery while doing other workJiggling the battery while doing other work Dirt on the motherboardDirt on the motherboard Electrical surgesElectrical surges Faulty power suppliesFaulty power supplies Chip creepChip creep

Losing CMOS SettingsLosing CMOS Settings

If your system keeps resettingIf your system keeps resetting

Replace the batteryReplace the battery

Common symptoms of low batteryCommon symptoms of low battery

Slow running clockSlow running clock

Clock resetting to January 1Clock resetting to January 1stst

Clearing CMOS SettingsClearing CMOS Settings

To clear the CMOS settings, place the shunt To clear the CMOS settings, place the shunt on the CMOS jumperon the CMOS jumper

Resets to factory settingsResets to factory settings

Resets passwordResets password

Flashing ROMFlashing ROM

Flash ROM chips can be reprogrammedFlash ROM chips can be reprogrammed

Download program from manufacturerDownload program from manufacturer

Copy program to floppyCopy program to floppySome programs will run within WindowsSome programs will run within Windows

Boot to floppy and run programBoot to floppy and run program

Thank youThank youThank youThank you

Mohd Saiful Rizal bin YusoffMohd Saiful Rizal bin YusoffHasani EnterpriseHasani Enterprise

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Mohd Saiful Rizal bin YusoffMohd Saiful Rizal bin YusoffHasani EnterpriseHasani Enterprise