1. Booting Up
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boot.ppt

2. first 64K computer address space
what is in a PC’s memory when the computer is off?
most of RAM is empty when the PC first powers up
RAM is volatile because its contents are lost when power goes off
but, two small parts are different
read-only
non-volatile
EEPROM (contains code)
0 8K 16K 24K 32K 40K 48K 56K 64K
RAM
battery-backed RAM (contains hardware settings)
when the PC first powers up, where is the operating system?
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boot.ppt

3. battery-backed RAM battery-backed RAM contains a simple database
also called the CMOS
a program called “Setup” is used to modify it
you can start Setup only while booting the computer
its data describes hardware parameters
time/date
what disk drives are present
what kind of display is present
how much memory is present
how fast some components should run
etc.
0 8K 16K 24K 32K 40K 48K 56K 64K
RAM
EEPROM (contains code)
battery-backed RAM (contains hardware settings)
how does the configuration data get modified?
plug and play devices
the Setup program
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boot.ppt

4. the EEPROM
the EEPROM contains the programs needed to start the computer
also called the BIOS, or the firmware
because it contains only programs, it can be read-only:
BIOS routines (a minimal keyboard/display driver)
POST routines (e.g., RAM parity check, keyboard test)
setup program – lets users view or modify hardware settings
bootstrap program – searches disk drives for an operating system
0 8K 16K 24K 32K 40K 48K 56K 64K
RAM
EEPROM (contains code)
battery-backed RAM (contains hardware settings)
how does the BIOS get updated if its programs need to change?
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boot.ppt

5. add-on boards also contain BIOS chips
the motherboard BIOS contains code to access the keyboard, floppy drive, ATA (IDE) hard disk controllers, USB devices, and disk drives
a computer system can contain several BIOS firmware chips
plug-in adapter cards such as network interface cards and video boards often include their own BIOS
complementing or replace the system BIOS code for the given component
CMOS (“Setup”) database maps these extra BIOS programs into the low memory address space
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boot.ppt

6. what is a disk drive? a piece of physical hardware
non-volatile storage
programs on a disk drive must be loaded into RAM before they execute
disk drives must be subdivided into partitions
the act of writing on a disk drive to partition it is called partitioning
you have to know which OS will use the partition before you create it
partitions have to be formatted with a particular file system
typically, each OS uses a different file system
PC partitions have one or more logical drive letters associated with them
Solaris partitions have directories associated with them (“mounted”)
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boot.ppt

7. more about disk drives what is fdisk?
a utility from Microsoft for partitioning disks
part of the original DOS 6.x operating system
a more versatile utility: Partition Magic
what is a boot sector? (master boot record, or MBR)
the first accessible “sector” on a drive
it contains:
a table of (up to 4) partitions
optionally, code to bootstrap an OS from the “active” partition
the partition table in the boot sector contains up to 4 entries:
primary partition
takes up one entry in partition table, and contains a single logical drive
extended partition
takes up 1 entry in partition table, and may contain multiple DOS, Linux or other partitions (logical drives in Windows)
Solaris partition
takes up 1 entry in partition table
active partition
a primary partition that is bootable
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boot.ppt

8. starting Windows on an x86-based computer
since 1981, all x86-based computers use the partition style known as the master boot record (MBR)
first used by MS-DOS in 1981, and continued up through Windows XP Pro
when you start your computer, the first code that executes is the BIOS
BIOS loads the bytes from the MBR of the boot device into memory
it then transfers control to the bytes just loaded into memory
the MBR’s first bytes are code to start loading the operating system
but first, it has to find the operating system
It looks that up in the partition table (stored in the end of the MBR)
Because MBR is the only partition style available on x86-based computers running Windows XP or earlier, it is used automatically and you do not need to choose this style
Dynamic disks were introduced in Windows 2000 and they provide features that basic disks do not, such as the ability to create volumes that span multiple disks, including fault-tolerant mirrored and RAID-5 volumes.
Requires a GPT partition style
GPT stands for “GUID Partition Table”
GUID stands for “Globally Unique ID”
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boot.ppt

9. MBR
the first physical sector on a disk contains a data structure known as the Master Boot Record (MBR). The MBR contains the following:
a boot program (up to 442 bytes in size)
a disk signature (a unique 4-byte number)
a partition table (up to four entries)
an end-of-MBR marker (always 0x55AA)
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boot.ppt

10. enter GPT partitions and EFI
Extensible Firmware Interface (EFI) is a specification that defines a software interface between an operating system and platform firmware.
EFI is intended as a significantly improved replacement of the old legacy BIOS firmware interface historically used by all IBM PC compatible personal computers
the EFI specification was originally developed by Intel
now managed by the Unified EFI Forum and is officially known as Unified EFI (UEFI)
Used first on Itanium processor systems
Also used by 64-bit Windows versions
Vista can use them as data disks (but not boot drives)
XP Pro cannot use them at all
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boot.ppt

11. kinds of hard drives today
basic MBR disk – Windows XP systems all use this
basic GPT disk
dynamic MBR disk
dynamic GPT disk
if using EFI, there also has to be a special partition containing the particular EFI code your computer system happens to need
what are the implications of this?
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boot.ppt

12. Boot Camp
I have a MacBook capable of running both Mac OS X and Windows XP
the laptop is 2 years old
cost was $ $300 for Windows XP Pro license
it only has Mac OS 10.4, “Tiger”
not 10.5, “Leopard”, the latest
came with 512K, not enough memory to run Leopard
how did I get it to run Windows?
Mac OS 10.4 let me download a special program called Boot Camp
it created a Windows partition, after which, I installed Windows XP Pro on that partition
coupla years went by…
recently, my Windows XP install partition got sick; I needed to restart Windows
it died in a way that even Mac OS X was unable to redo the Windows partition
so I also had to reinstall Mac OS X (10.4)
Boot Camp was cripple-ware
“expired”; could no longer download it
what to do?
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13. the end of this slideset
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14. I have a MacBook with Apple’s “Boot Camp” program on it
What does Boot Camp do?
Can I just run Windows on my MacBook without
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boot.ppt