Transcript Document

University of Moratuwa
Department of Electronic and Telecommunication Engineering
Operating Systems
Dr. E.C. Kulasekere
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
What's Next?
• Assembled computer available.
• Choice of right tool to integrate.
• Should we use a screwdriver to
pound nails into the wall?
• Any guidelines to choose the right
tool?
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Operating System
Selection
• Single or Multiple OSs?
• Type of OS; Microsoft-style or Unixstyle?
• Matching the OS to your ability,
application software need and
urgency of use.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Multi-OS System
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Leave plenty of space.
Consider running an Emulator.
Setup data exchange between OSs.
Investigate Hardware needs.
Drivers available for current
hardware?
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Hardware Compatibility
Issues
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The Motherboard.
I/O and peripheral cards.
The CPU and its performance.
Memory capacity adequate?
Mass storage devices.
Multimedia compatibility.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Expectations From a
New OS
• Give yourself adequate time.
• Research what problems need to be
solved.
– Software based.
– Stability of OS.
– Curiosity
• Expect a learning curve.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
OS Installation Basics
• Disk Partitioning.
– Shared partition?
– In separate partitions?
• Partition types.
– Primary partitions
– Extended partitions.
– Logical partitions
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
OS’s for x86 Hardware
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DOS variants.
Windows 9x.
Windows NT/2000.
Unix variants.
Any advantages of using a particular OS?
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Windows 9x
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Introduced 32 Bit support.
Requires at least a 386 computer.
Does preemptive multitasking.
VFAT extension with long filenames.
FAT32 support.
Tighter network integration.
Boot into a GUI.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
When to Move on
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Internal and External security is lax.
Multi-user configuration is primitive.
Questionable stability.
DOS based OS core.
Low performance compared to NT
and UNIX.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Windows NT/2000
• 32-Bit multitasking kernel.
• Works on non-Intel platforms.
• NTFS which is faster and more
reliable than FAT is introduced.
• Improved multi-tasking and
networking.
• User access control.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
When to Move on
• Imperfect 16-Bit support.
• NTFS incompatibility with most other
OSs.
• Reduced hardware support
(Windows 2000 rectifies this).
• Concurrent multi-user performance
is low.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Linux
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Open source and free.
Robust multi-tasking environment.
Excellent networking capabilities.
Customizable X-windows GUI.
Excellent, stable multi-user
capabilities.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
When to Move on
• Steep learning curve.
• Open source results in network
security problems.
• Limited number of end-user
applications.
• Poor hardware support.
Short Course on Computer Hardware and Assembly
July 16, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
The Boot Process
• Multi OSs should be coaxed to boot.
• BIOS as a boot loader.
• Methods the boot loaders work in
multi OS systems.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
BIOS History
• 16-Bit and 32-Bit addressing and the
BIOS.
• BIOS interface with low level
Hardware.
• BIOS as a POST and boot handoff.
• CMOS and PnP uses of BIOS.
Short Course on Computer Hardware and Assembly
July 17, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
BIOS Types
• AMI BIOS, Phoenix BIOS, Award
BIOS.
• Add on BIOS cards.
• Video BIOS.
• SCSI BIOS.
• Sound and Multimedia hardware
BIOS.
Short Course on Computer Hardware and Assembly
July 17, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
BIOS Updates
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Rewriting EEPROM or Flash BIOS.
Upgrades eliminate bugs.
Upgrades add improvements.
Process is extremely dangerous.
May result in an unbootable system.
Sketch of finding and upgrading.
Short Course on Computer Hardware and Assembly
July 17, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
BIOS and Hard Disks
• The connection to OS installation.
• Motherboard BIOS controls EIDEs.
• SCSI Hard Disks are controlled by
SCSI BIOS.
• What is CHS disk geometry?
Short Course on Computer Hardware and Assembly
July 17, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
The Modern Hard Disk
Short Course on Computer Hardware and Assembly
July 17, 2002
University of Moratuwa
Department of Electronic and Telecommunication Engineering
The Hard Disk
• Rotational speed is important.
• Head reads typically 512 Bytes at a
time.
• Cylinder, head, sector---CHS
• BIOS reads the CHS to understand
address of boot loader.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
The 1024 Cylinder Limit
• Result of bit allocation for the CHS
geometry in the BIOS.
• At Boot time only the 1024 cylinders
are seen
• OS loader should be within this limit
to load.
• In olden computers the limit on hard
disk capacity is 540 MB.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Getting around 1024
limit
• Ignore it. Make sure the boot loader
is within the 1024 cylinders. Eg.
Linux
• CHS geometry translation carried out
in the hard disk controller. Total drive
capacity remains the same.
• SCSI uses LBA which has one 28-bit
sector number.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Boot Loader – Single OS
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Boot Loader – Multi-OS
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Types of Boot Loaders
• Floppy based. Eg. Linux. Can be
used to check a new OS.
• MBR-Based. Popular but can be
destroyed by other OS installation
• Boot sector- based. Less susceptible
to be destructed with new
installations.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Common Boot-loaders
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NT-loader.
Linux LILO.
System commander.
Boot magic.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Uses of Partitioning
• TO save space. Eg. FAT16 partition
sizes should be less than 511MB.
• Easier disaster recovery.
• Location of data can be positioned
so that hard drive seek is easier and
head wear is minimum.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Tools for Partitioning
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FDISK. For DOS and Linux
Windows NT disk administrator
PartitionMagic.
FIPS.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
FDISK (DOS)
• Tightly coupled with the partition type.
• Primary should be created before
extended.
• Unable to create more than one primary.
• Partition placement is not allowed. The
allocation is automatic.
• Unable to cope with non-FAT partitions.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
NT Disk Admin
• Graphical user interface.
• Can create multiple primary partition.
• Can create a logical partition without
a primary partition.
• Can delete non-FAT partitions.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
PartitionMagic
• Graphical user interface.
• Can create multiple primary partition.
• Can create a logical partition without a
primary partition.
• Can delete non-FAT partitions.
• Create file system.
• Moving and resizing partitions.
• Copying and converting partitions.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Partition Formatting
• Low-level:--Erases the data and file
system structure. Takes time.
Rebuilds the disk structures.
• High-level:--Basic structure like boot
sector and root directory are created.
Takes a short time.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
When to modify and
repartition?
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Adding an OS.
Deleting an OS.
Shifting disk space requirement.
Adding a new hard disk.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Consequences of
Repartitioning
• Drive letter changes: Software
becomes unusable. Extreme cases
the OS becomes unbootable.
• UNIX device identifier changes:
mount points can change and the OS
becoming unbootable. Change
/etc/fstab to reflect changes.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
When to modify and
repartition?
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Adding an OS.
Deleting an OS.
Shifting disk space requirement.
Adding a new hard disk.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Optimizing Partitions
• Outer most part of a disk platter is
faster than the inner most platter in a
hard disk.
• Applications that need best
performance should be placed first.
Eg. Swap space, most frequently
used programs, large data files.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Dangers of Too Many
Partitions
Increased head movement can damage hard disk
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Installing the OS
• Microsoft OSs copy the installation files to
hard disk for optimal performance.
• For UNIX OSs choose the partitions
appropriately so that disaster recovery
can be easier. Choose appropriate code
changes. Position the /boot below 1024
cylinders or use a floppy.
• Install MS OS before anything else since it
damages other OSs.
Short Course on Computer Hardware and Assembly
July 18, 2015
University of Moratuwa
Department of Electronic and Telecommunication Engineering
Installation Problems
• If the system is unbootable, use a
floppy to boot into the system and
make changes. Do not reinstall as a
first option.
• Have the data in a shared partition.
Short Course on Computer Hardware and Assembly
July 18, 2015