1 / 48

Unit 5: Lets discuss the BIOS, CMOS, POST, and Boot Process! Rajeev Gupta (Mr. RAJ)

Unit 5: Lets discuss the BIOS, CMOS, POST, and Boot Process! Rajeev Gupta (Mr. RAJ) 15 Years of IT & Training Experience in

lucas
Télécharger la présentation

Unit 5: Lets discuss the BIOS, CMOS, POST, and Boot Process! Rajeev Gupta (Mr. RAJ)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Unit 5: Lets discuss the BIOS, CMOS, POST, and Boot Process! Rajeev Gupta (Mr. RAJ) 15 Years of IT & Training Experience in Hardware and Networking. Training is my Passion. I am really excited about brining this information to you. I will do my best to give you a perfect place to launch an IT career and I promise it will help you tremendously in knowing how the PC works. You will be building on the foundation no matter where you go.

  2. BIOS • Basic Input Output System • A chip on the motherboard • BIOS is stored in the PC’s ROM chip • EPROM • Firmware • BIOS will support all hardware on an 286 AT PC • Drivers are required for all other hardware Mr. Raj Class: Operating Systems Lecture

  3. Firmware • Gray area between hardware and software • Software written permanently or semi-permanently to a computer chip • Used to control electronic devices • Implemented in PC with BIOS and CMOS

  4. BIOS • Basic Input/Output System • A set of software instructions stored on a chip on the motherboard • Enables basic computer functions • Common BIOS manufacturers: • AMD • AMI • AWARD • MR BIOS • PHOENIX • Many use shadowing

  5. Function of the BIOS • Stores a set of instructions to tell the PC how to control devices • Provides low-level hardware access • Tests hardware on startup using POST • Runs “bootstrap loader” after POST • After this the operating system takes over Mr. Raj Class: Operating Systems Lecture

  6. APPS OS AT computer BIOS Hardware The BIOS sits between the hardware and the Operating System Mr. Raj Class: Operating Systems Lecture

  7. BIOS updates • BIOS implemented either in: • ROM: Programmed at factory • Flash memory: Can update, “flash,” the BIOS • Update if you: • Have device problems or other bugs that PC manufacturer says are caused by BIOS problems • Have device problems that can’t be attributed to anything else; have exhausted all other troubleshooting avenues • Need to use new hardware options that are supported by motherboard but not by BIOS

  8. BIOS update sources • Links to BIOS updates and flashing utilities on PC manufacturer’s Web site • BIOS is tailored by each PC manufacturer • Don’t go to BIOS manufacturer’s Web site

  9. Determining the BIOS version • Open System Information • Record BIOS Version/Date field value • If present, record SMBIOS field value

  10. Flashing the BIOS • Determine current BIOS version • Go to PC manufacturer’s Web support pages • Compare available updates with current version • Download new BIOS version • Download flashing utility • Close all open windows • Open flashing utility; follow instructions • Restart PC

  11. BIOS update failures • Don’t update your BIOS unless you must • Never turn off your computer during a BIOS update • Connect to a UPS • Use the correct BIOS flash utility • Follow instructions exactly • Back up BIOS if possible

  12. Recovering from a failed update • Use BIOS backup to restore previous version • Use “boot block” • Use flash recovery jumper switch • Obtain new BIOS chip

  13. Bad CMOS battery • BIOS data retained due to CMOS battery • Older PCs had a soldered battery—not replaceable • Newer PCs have removable battery

  14. CMOS • Area of memory that stores BIOS configuration information • Battery provides power to CMOS • Type of computer chip: complementary metal oxide semiconductor • Can maintain information without a supply of power

  15. CMOS battery

  16. CMOS configuration • Configure with system setup utility • Built in BIOS • Locate on separate hard disk partition • Stored on disc • Access to utility varies by manufacturer • List of CMOS access keys: • http://murfsgarage.cybertechhelp.com/cmossetup.htm

  17. CMOS configurable settings • Date and time • CPU options • Optical drive options • Floppy drive options • Hard drive options • Serial port options • Parallel port options • Integrated devices • Plug and Play • Power management options • Virus detection • Boot password continued

  18. CMOS ROM BIOS CHIP Changeable hardware • RAM • hard drive • floppy drive etc. Unchangeable hardware CMOS Battery CMOS also acts as a clock Stores date and time • keyboard • pc speaker • video CMOS Updates to hardware, e.g. adding RAM or changing a hard disk are stored in CMOS

  19. CMOS • Complementary Metal Oxide Semi-Conductor • Stores roughly 64Kb of data • Part of the Southbridge in most PCs • Specs stored in CMOS must match hardware • Allows you to access the BIOS • When hardware is changed/updated, CMOS must be updated Mr. Raj Class: Operating Systems Lecture

  20. Accessing BIOS through CMOS setup • CMOS can only be accessed when the PC is booting • Key combination at start-up • Changes are stored on a NVRAM CMOS chip • AMI and AWARD BIOS – DEL key • PHOENIX BIOS – CTRL, ALT and ESC keys or F2 • The mouse doesn’t work in CMOS setup! Mr. Raj Class: Operating Systems Lecture

  21. The CMOS chip • CMOS is stored in SRAM chip called Non-Volatile Random Access Memory(NVRAM) • Stores data which is used by the BIOS • NVRAM is powered by CMOS battery • Modern BIOS is stored in EEPROM • EPROM and SRAM means motherboards are updateable • Older motherboards • Resetting CMOS Mr. Raj Class: Operating Systems Lecture

  22. AMIBIOS Main Menu Always document existing settings before making any changes Mr. Raj Class: Operating Systems Lecture

  23. Standard CMOS Features Mr. Raj Class: Operating Systems Lecture

  24. Advanced BIOS Features Mr. Raj Class: Operating Systems Lecture

  25. Advanced Chipset Features Mr. Raj Class: Operating Systems Lecture

  26. Power Mangement Features Mr. Raj Class: Operating Systems Lecture

  27. PNP/PCI Configurations This should be set to Yes Mr. Raj Class: Operating Systems Lecture

  28. Integrated Peripherals N.B. Exam - ECP or EPP mode allows printers to access DMA channels and are 10 times faster than bidirectional mode Mr. Raj Class: Operating Systems Lecture

  29. PC Health Status Mr. Raj Class: Operating Systems Lecture

  30. Frequency/Voltage Control Mr. Raj Class: Operating Systems Lecture

  31. Other CMOS Settings • Load High Performance defaults • Load BIOS setup defaults • Supervisor password • User password • Disconnect the battery for 1 hour to erase the password! • CMOS can also be cleared using a jumper Mr. Raj Class: Operating Systems Lecture

  32. Clear CMOS Jumper Mr. Raj Class: Operating Systems Lecture

  33. Troubleshooting CMOS • Loss of time/date settings • Chip creep • Voltage of new battery • Old PCs = 3.6 volt batteries • Newer PCs = 6 volt battery Mr. Raj Class: Operating Systems Lecture

  34. POST process Power-on self test • BIOS tests core hardware • BIOS tests video subsystem • BIOS identifies itself, including its: • Version • Manufacturer • Date • BIOS tests main system memory

  35. Beep codes • Inform user of errors before display is loaded • Vary by manufacturer • www.computerhope.com/beep.htm • Common beep codes: • 1 short beep = No problems found • 3 long beeps = Keyboard error • 8 short beeps = Video adapter memory problems • 9 short beeps = BIOS problem • 1 long + 3 short beeps = Memory error

  36. Numeric codes • Informs user of errors after display is loaded • Vary by manufacturer • IBM numeric code examples: • 151 = Real time clock failure • 161 = Bad CMOS battery • 162 = Configuration mismatch • 164 = Memory size mismatch • 201 or any 20# = Memory failure • 1762 = Hard drive configuration error

  37. The boot process • You turn on the power • Timer chip sends reset signals to CPU to prevent booting • Power supply performs internal checks; sends Power_Good signal to CPU • Timer stops sending reset signals to CPU • CPU loads BIOS and BIOS extensions • BIOS checks whether this is a cold or warm boot continued

  38. The boot process, continued • If cold boot, BIOS performs POST • BIOS reads CMOS and configures devices • Plug and Play devices detected and configured • BIOS determines which drive to boot from • BIOS reads the master boot record from drive • OS takes over and completes the boot process

  39. Boot devices • Used to load operating system • Current: • Internal hard disk • Optical drive: CD or DVD • USB drive: flash drive or external hard disk or optical drive • Network drive, using a PXE network interface card • Older: • Floppy disk drive • SCSI device • Zip drive

  40. Boot devices in the system BIOS

  41. BIOS-related problems • Devices misidentified • Wrong memory size reported during POST or available during booting • Hard drive inaccessible • System won’t boot from hard drive • System boots from the wrong device • Date and time incorrect or reset after computer is turned off

  42. POST-related problems • There’s no video; instead, the computer sounds 8 short beeps • The system emits 3 long beeps • The system emits 1 long and 3 short beeps • POST code 162 is displayed • POST code 164 is displayed

  43. CMOS-related problems Error messages: • Non-system disk or disk error • Display type mismatch • Memory size mismatch • CMOS checksum failure

  44. Startup Routine Step 1: POST Step 2: Bootstrap Loader Step 3: Master Boot Record Mr. Raj Class: Operating Systems Lecture

  45. A detailed look at POST • “Devices go forth and test yourselves” • Only checks devices listed in BIOS • Beep codes • Refer to motherboard manual • Text errors • “Missing NTLDR” • “Keyboard error or no keyboard present” • POST cards Mr. Raj Class: Operating Systems Lecture

  46. Startup Routine • 1. During the POST, the BIOS tells drivers to “test themselves” and report back • Problems are flagged either by beeps codes or by messages on the screen • e.g. 301 Keyboard failure • 2. Bootstrap Loader • 3. Master Boot Record • IO.SYS • NTLDR • After this the operating system takes over Mr. Raj Class: Operating Systems Lecture

  47. POST Error Codes Mr. Raj Class: Operating Systems Lecture

  48. BOOT Process in detail • CPU’s power good wire “wakes up” the CPU • CPU reads first line of POST program • Bootstrap loader runs • Check if disk is in FDD drive • Look for O.S. on boot sector of hard drive • NTLDR (Windows 2000/XP) or IO.SYS is loaded into RAM • Control is transferred from bootstrap loader to the O.S. • Core O.S. files, drivers and services are loaded into RAM Mr. Raj Class: Operating Systems Lecture

More Related