2.  An operating system is the most
important software that runs on a
computer. It manages the computer's
memory, processes, and all of its
software and hardware.

3.  Boot Loader
This is a piece of software that_ resides on the non volatile or persistent memory of a
computer system, which is responsible for loading the main OS. The need for a boot
loader comes from the fact that non volatile memory such as ROM is limited in size and
he entire OS run-time image cannot fit into it.
Also, the computer hardware alone (without software) cannot handle complex file-
systems and peripherals such as those on hard-disks and flash memories. So, in a typical
system, after a power-on or a reset, the CPU starts executing the boot loader code
residing in the ROM. The boot loader contains code to initialize peripherals of the CPU to
a minimal extent - just enough to obtain the OS run-time image from a peripheral
device to the main memory (RAM) and transfer the control to the OS start code.
The boot loader can obtain the OS Image from a local storage device such as a hard
disk, compact flash card or download it via a serial connection, Ethernet connection or
an USB interface. The boot loader may have to uncompress the OS Image in case it is
stored in compressed form.
Modern boot loaders, such as UBOOT (used mostly for Linux) and EBOOT (used for
Windows CE) contain a host of other features such, as supports multiple CPUs (ARM,
PPC, MIPS, X86), Execute from Flash (NOR Flash), File download from serial, Ethernet, USB
etc. Some OS terminology may include boot loader as a part of the Board Support
Package (BSP).

4.  Board Support Package
The BSP for an operating system is an implementation specific code for a given HW
board containing the CPU and other peripheral devices such as memory and memory
controllers, timers, interrupt controllers, USB, Ethernet etc. In case of a SoC, a large part
of the 'board' is inside the IC, on the same silicon chip as the CPU core itself.
The BSP provides an abstraction of the hardware (CPU and peripherals) to the generic
OS interfaces. It facilitates communication between the OS and target HW device and
includes code to manage memory, handle interrupts, timers, power management, bus
abstraction, generic I/O control codes (lOCTLs), and so on.
The BSP is one of the most complex parts of the OS porting and integration effort and
contains code for the following essential OS services:
Memory Management: The OS may use virtual memory to manage the RAM. The BSP
contains code to initialize the Memory Management Unit (MMU) and provide an
interface to the higher level OS layers to setup the memory access data structures such
as page tables.

5.  Timer: The OS uses the timer for many functions including task
scheduling - which is vital for its functioning. The BSP contains
code to initialize the timer hardware as per the needs of the OS.
Interrupt Handler: All peripherals to the CPU, such as Serial Bus,
USB, Camera Interface etc. typically use interrupts to signal the
CPU about data availability or data transfer completions. The
CPU then executes the appropriate Interrupt service routines
(ISR) to take the necessary actions. The BSP initial¬izes the
Interrupt mechanism.
Power Management: The OS needs to conserve power on most
devices by providing p'ower saving modes such as Full Power,
Hibernation, Sleep etc. When the system restarts, it needs to
invoke the correct code to handle the wake-up. The BSP
initializes the power management system of the Soc. Many more
functionalities related to the OS operations are a part of the BSP,
which need to be implemented or ported in order to make the
OS utilize all features of the underlying soc.

6.  DEFINITION:For hardware functions such
as input and output and SISTEM
ALLOCATION the operating system acts
as an intermediary between application
programs and the computer hardware.

7.  We learn a lot about operating systems.
 We have to be sure about how we work
on the computer.
 In the video we can see that the
computer had a lot of users.

8.  http://www.computerhope.com/os.htm
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