CHAPTER 5 BIOS

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CHAPTER 5 - BIOS

• BIOS - ALL THE DRIVERS(PROGRAMS) WORKING TOGETHER
  AS AN INTERFACE BETWEEN THE HARDWARE AND THE
  OPERATING SYSTEM.
• APPLICATION PROGRAM WANTS X FROM O/S
• THE O/S ALWAYS ASKS FOR XY
• BIOS 1 TELLS HARDWARE A2X, BIOS 2 TELLS HARDWARE
  B21, BIOS 3 TELLS HARDWARE AA2
• THE APPLICATION PROGRAM GETS WHAT IT WANTED -
  X, WHICH EVER BIOS/HARDWARE INTERFACE YOUR
  SYSTEM HAS.

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• BIOS HARDWARE/SOFTWARE PARTS
• MOTHERBOARD ROM BIOS PART
• CARD BIOS PART (VIDEO, SCSI, NIC)
• DRIVERS (LOADED FROM DISK)
• BIOS STORED IN FIXED ROM, CMOS STORED IN
  CHANGEABLE RAM.

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• MOTHERBOARD BIOS - 5 OR 6 CHIPS - 1
• EXECUTABLE PROGRAMS AND DATA
• POST - SIMPLE HARDWARE TESTING
• BIOS SETUP - CONFIGURATION AND SETUP
• BOOTSTRAP LOADER - LOOKS FOR MASTER BOOT SECTOR
  ON HARD DRIVES ENDING IN 55AAh AND EXECUTES THE
  CODE THERE WHICH IN TURN LOADS THE OPERATING
  SYSTEM BOOT SECTOR AND THEN THE OPERATING SYSTEM
• BIOS - COLLECTION OF PROGRAMS(DRIVERS) TO
  INTERFACE(GO BETWEEN) THE O/S TO THE HARDWARE
• ROM HARDWARE - (SEMI) PERMANENT READ ONLY. A
  SUBSET OF THE SYSTEMS RAM.
• STARTS AT F0000h OCCUPING 64KB, INCLUDES FFFF0h
  STARTUP INSTR ADDRESS (FOR GROWTH)

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• 55AAh INDICATES THE START OF ADAPTER ROM
• CHECKSUM ADDS ALL ROM BYTES AND DIVIDES BY THE
  SUM - REMAINDER SHOULD BE 100h DUE TO PROGRAMMERS
  fill BYTE.
• ADAPTER ROMS ARE EXECUTED(RUN) - VIDEO CARD
• SHADOWING ROM - ROM IS SLOW, RAM IS FAST
• ROM - CAST IN STONE - ETCHED
• PROM - PROGRAMMED IN STONE - ONE TIME PROG
• EPROM - UV LIGHT CAN ERASE FOR REPROGRAM
• EEPROM - FLASH ROM - SET JUMPER FOR HIGHER
  VOLTAGE. REPROGRAM YOUR CAR TOO. CHECK
  MOTHERBOARD MAKER FOR ROM UPDATES.
• ROM BIOS MANUFACTURERS
• OEMs - COMPAQ, ATT
• DEVELOP THEIR OWN
• ADAPT BIOS CODE FROM AMI, PHOENIX(HP) , AWARD,

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• AMI-BIOS ID STRING - P2 HANDOUT, CLASS COMPUER
• HOMEWORK - HAND IN TWO BIOS STRINGS, ANALYZE 1.
• DEL DURING POST
• PAGE 369 - 370 - AMI
• AWARD - PURCHASED BY PHOENIX - BIOS TO GO
• CTRLALTESC
• PHOENIX - PURCHASED BY HEWLETT PACKARD
• CLEAN ROOM - TEAM 1 STUDIES IBM BIOS AND WRITES
  SPECIFICATION
• TEAM 2 READS SPECIFICATION AND WRITES BIOS
• NO CHEATING!
• MICROID - UPGRADES ABANDONED BIOSs - FOR
• UPGRADE-SYSTEMBOARD MAKER,UNICORE
• NEED MAKE AND MODEL OF SYSTEM, VERSION OF BIOS
  (BIOS ID STRING AS DISPLAYED BY SCREEN), TYPE OF
  CPU
• WHY? LS-120, HD 8GB, ULTRA-DMA/100 IDE, ATAPI
  CD-ROM, PNP, Y2K AND LEAP YEAR BUGS, KNOWN BUGS,
  NEW FASTET CPUs, ACPI POWER MANAGEMENT
• REPLACE-ROM, PROM/REPROGRAM-EPROM, EEPROM

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• REPLACE-ROM, PROM/REPROGRAM-EPROM, EEPROM
• DIFFICULTIES - SPECIFIC TO THE HARDWARE
• MAKE/MODEL OF SYSTEM UNIT
• CPU TYPE
• CURRENT VERSION
• PART NUMBERS PHOENIX, AMI, AWARD
• CHIP REPLACEMENT
• FLASH
• WORKS WITH ANY DOS

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• iFLASH PROCEDURE - ALLOW NO POWER INTERRUPTIONS
• 1. SAVE OLD SETTING - ESECIALLY HD
• 2. RESTART AND GO TO DOS
• 3. FORMAT BLANK FLOPPY TO BE BOOTABLE
• 4. EXECUTE SELF EXTRACTING DOWNLOAD
• 5. FILES ARE EXTRACTED
• 6. RUN.BAT - PUTS FILES ON FLOPPY
• 7. RESTART SYSTEM WITH BOOTABLE FLOPPY
• 8. WHEN TOLD OF SUCCESS REMOVE FLOPPY AND REBOOT
• 9. GO TO CMOS SETUP AND CHECK
• 10. LOAD DEFAULT VALUES
• 11. REENTER UNIQUE SETTINGS

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• FLASH BIOS RECOVERY
• 1. CHANGE A JUMPER TO RECOVERY POSITION
• 2. INSERT UPGRADE FLOPPY AND REBOOT - YOU SEE
  NOTHING ON MONITOR BUT LED IS ON
• 3. LED GOES OFF - MAYBE 2 BEEPS
• 4. CHANGE JUMPER BACK TO NORMAL
• TURN COMPUTER BACK ON AND CHECK
• AVOID SYSTEMS WITH BIOS ON HARD DISK
• IML - INITIAL MICROCODE LOAD - NIGHTMARE

9

• ROM BIOS - CODE/PROGRAMS
• DOES THE POST, FINDS AND LOADS THE OPERATING
  SYSTEM, CONTINUES TO PROVIDE ACCESS TO THE
  PHYSICAL DEVICES, VIDEO, HARD DISK.
• FAST IMPROVEMENT
• TAKE ADVANTAGE OF NEW FEATURES
• CDROM
• IDE
• VGA, SVGA, XVGA
• VIRUS PROTECTION - BOOT SECTOR
• BOOT ORDER A,C - C,A

10

• BACKUP YOUR BIOSs CMOS SETTINGS
• PRINT WHEN UPGRADING MOTHERBOARD
• REPLACE BIOS - STEPS ON PAGE 383 - ENJOY!
• OOPS - RECOVER IT - PUT OLD ONE BACK IN
• MOTHERBOARD CMOS - TABLE 5.6 (52 bytes) - LOTS OF
  INFORMATION
• REPLACING A BIOS ROM - CHIP REPLACEMENT
• CMOS RAM DIAGNOSTIC BYTE (8 BITS)
• 10000000 - RTC LOST POWER
• 01000000 - CMOS CHECKSUM BAD
• 00100000 - INVALID CONFIGURATION - POST
• 00010000 - MEMORY SIZE ERROR - POST
• 00001000 - FIXED DISK/ADAPTER FAILED
  INITIALIZATION
• 00000100 - ADAPTERS DONT MATCH CONFIGURATION
• 00000010 - TIME OUT READING ADAPTER ID
• 00000000 - A - OK - NORMAL - NO ERRORS FOUND

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• CMOS SETTINGS
• AMI del
• PHOENIX - F2 - older ctrl-alt-esc or ctrl-alt-s
• AWARD - del or ctrl-alt-esc
• MICROID - esc
• IBM - F2
• COMPAQ - F10

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• BIOS SETUP MENUS - PHOENIX EXAMPLES
• MAINTENANCE
• MAIN
• ADVANCED
• SECURITY
• POWER
• BOOT
• EXIT
• ADDITIONAL - PAGE 407 - TABLE 5.32
• Y2K FOR AWARD, AMI, PHOENIX
• PLUG-AND-PLAY BIOS-PNP0XXXPNPC001
• PLUG-AND-PLAY BIOS, EXTENDED SYSTEM CONFIGURATION
  DATA, PNP O/S, PNP DEVICE ID FROM THE CD - e.g.
  PNP0909 - S3 INC 911/924

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• BIOS ERROR MESSAGES
• BEEPS
• CODES TO I/O PORT 80h
• SEE CD FOR 11 EDITION
• GENERAL BIOS BOOT TEXT ERROR MESSAGES
• IBM
• NO ROM BASIC
• AMI
• NON-SYSTEM DISK OR DISK ERROR
• AWARD
• DISK BOOT FAILURE, INSERT SYSTEM DISK AND TAP
  ENTER
• PHOENIX
• NO BOOT DEVICE AVAILABLE
• OR
• NO BOOT SECTOR ON FIXED DISK
• 4 PARTITIONS TABLE ENTRIES POSSIBLE (80h ACTIVE)