Plug and Play (PnP) is a system for
configuring devices, usually in the form of add-in cards, that enables them to
work together without conflicting with each other. PnP consists of:
* PnP and non PnP cards (devices)
* PnP initialisation and run-time routines within the Operating System (OS) and
* PnP BIOS routines
There are three types of PnP cards
that can be auto-configured:
* PnP ISA
* PC Cards (PCMCIA).
All other devices are non PnP, have
a static configuration and classified as ISA Legacy Devices. PnP devices are
configured around Legacy devices. Windows95 configures Legacy devices with the
'Add New Hardware' wizard. Resource Usage (IRQs, I/O ports, DMA channels and
memory windows): PnP can use one of two methods of determining resource usage.
1. Determine the resources that are
not generically detectable and establish the areas unavailable for configurable
2. Extended System Configuration Data (ESCD) method. ESCD stores Legacy
information and the Last Working Configuration (LWC) of configurable devices.
This allows the system to ensure that resource assignment and device placements
are the same each time the computer is powered on. This is important when using
device drivers that get their resource allocation information from a static
source, such as the command line parameters in config.sys file.
A fully PnP compliant system
requires a PnP BIOS. ESCD configures PnP boot devices as part of the Power On
Self Test (POST) before booting the operating system. ESCD also allows run-time
software (Windows95 Device Manager) to request specific resource assignments
for PnP devices. This allows difficult to place configurations to be manually
setup or disabled.
PnP elements: There are four
elements to a PnP system.
1. The PnP BIOS starts the auto-configuration of the PnP cards during the POST.
This in turn isolates any Legacy devices and ascertains the resource needs of
2. The ESCD functions are used to
determine resources already in use by Legacy devices, and which are available
for PnP devices. A PnP BIOS must be able to configure the card or cards that
are required to boot the operating system (video and disk controllers), and may
also configure all the cards in the computer, which is necessary for operating
systems that don't feature native support for PnP cards. After identifying the
PnP cards, the PnP BIOS compares these cards with those in the ESCD. If found,
they are configured as stored in the corresponding ESCD entry. This ensures
that when no new hardware has been installed, the PnP devices are configured
identically for each session. If the PnP BIOS cannot find an entry in the ESCD,
it consults the ESCD to determine what resources are free and assigns these to
the new card. In addition, the ESCD allows system software and utilities to
communicate with the BIOS, by placing their desired resource allocations in the
3. The Configuration Manager (CM),
configures the PnP cards not configured by the PnP BIOS, by using the ESCD in a
similar manner as the BIOS does.
4. The ISA Configuration Utility
(ICU) is designed to assist in determining a conflict-free configuration for
standard (Legacy) ISA cards, as well as providing advanced configuration
support for PnP cards. The ICU will allow certain functions in multi-function
cards to be disabled and the configuration of particular cards to be locked:
primarily for use with non PnP supporting operating systems.
The PnP BIOS:
The PnP BIOS performs the following steps to configure the PnP devices before
starting the machine:
* Builds a structure called the Resource Map, to determine the available system
resources - IRQ, I/O ports, DMA channels and memory windows.
* The Resource Map is then initialised to indicate the resources available.
* The BIOS determines the resources used by the system board devices, either by
looking up the information in the ESCD, or by enquiring from the BIOS the
resources used by system board devices.
* The PnP BIOS then interrogates the ESCD in order to determine resources that
are allocated to Legacy cards, and updates the Resource Map. At this stage, the
Resource Map contains all the necessary information on all Legacy devices.
* PnP ISA cards are examined to establishes its resource needs.
* After identification, the boards are configured, starting with the last known
working configuration for each card in the ESCD. For new cards, the system will
use the first alternative configuration that matches the card's resource
requirements. However, if none are found, then the next set of available
resources is tried. If the system runs out of resources, it will go back to the
previously configured cards and attempt to re-configure them to make room for
the new card.
* The BIOS then scans the standard expansion BIOS memory area looking for the
expansion BIOS signatures for Legacy ISA and PnP ISA cards. These are
initialised on detection.
* The PCI Configuration Space is examined and PCI devices initialised. As PCI
devices are fully configurable by definition, these devices are configured on a
first come/first served basis. Again, the last working configuration stored in
the ESCD is tried before any attempt to dynamically configure resources.
* If one or more PCI cards can't be configured, an error is generated and the
task of configuration is passed to the Configuration Manager.
* The expansion BIOSs are initialised and the ESCD structure updated with the
new PCI device configurations - ESCD data for PnP ISA card configurations is
carried out by the Configuration Manager.
Looking for Android 4.1 Jelly
Bean for Galaxy Y? Yes, of course you can. Find out details after the jump!
Thanks to S5360 custom ROM for
Android 4.1 Jelly bean, now you can update your Galaxy Y to Android 4.1. In
this post you will learn how to update your Samsung Galaxy Y to Android 4.1
Jelly Bean using S5360 custom ROM.
Before you proceed, you will need to
have fulfilled following requirements:
You have installed your Galaxy Y USB drivers on your
You smartphone should have 70-80% charge remaining.
Your Galaxy Y should be rooted.
This guide is only meant for Galaxy Y GT-S5360,
dont try it on other variants of Galaxy Y. You can check your Galaxy Y
version in Settings –> About phone.
Last but not least, backup your important data like
Call logs, SMS and other data in stored in phone memory so in case if
anything goes wrong, your data is not hurt.
to Install Android 4.1 Jelly Bean For Galaxy Y
Step 1)Download Android 4.1 Jelly Bean for Galaxy Y.
Step 2) Connect your Galaxy Y USB to your computer using the USB
Step 3) Copy the downloaded file to your SD card.
Step 4) Turn off your phone and then turn it in again in the
recovery mode by pressing and holding the Volume UP + Home + Power
buttons. Alternatively you can check this:Â Enter Any Android Device
into Recovery Mode
Step 5) Now you will see exclamation mark on your phone screen.
Again hold your volume up and power buttons. Now your Galaxy Y is in recovery
Step 6) Once your smartphone is in ClockworkMod recovery, you are
ready to perform a Nandroid backup of your existing ROM. For that you will need
to select Backup and Restore option followed by selecting Backupagain in next windows. Once the backup is completed, you are ready to go
back to main recovery menu.
Â Step 7) Now you will need to wipe the previous ROM first. For that
select Wipe data/factory reset option and select Yes
to confirm the action.
Step 7) Now select Install zip from sdcard and then
select choose zip from sdcard.
Step 8) Navigate to Custom ROM file we have just uploaded to SD card
in step 3 and select it using power button. Confirm the installation on the
next screen and the installation procedure should start now.
Step 9) Once installation is completed, go back to main recovery
menu and select Reboot System Now.
Recommended: Before rebooting your phone from CWM Recovery, go to CWM
Recovery main menu and select Wipe Dalvik Cacheunder Advance
option to perform the Dalvik cache wiping.
So now you have successfully
installed the Jelly Bean for Galaxy Y custom ROM on your phone. Your phone will
now boot for the first time in Android 4.1 Jelly Bean, so it might take some
time on first boot. Congrats your Galaxy Y is now updated to Android 4.1 Jelly
Bean. You can verify it by going to Settings –> About Phone.
Like Jelly Bean For Galaxy Y?
Going Back to Previous State: If you encounter any serious problem during installation of
this custom ROM, then no worries, you can restore your phone to previous state
provided you followed Step 6. To restore your phone to previous ROM, boot your
phone to recovery mode and select Backup and restore and then
select the backup file from the list.
For future updates, follow the
XDA-Thread over hereif you need help regarding this Jelly Bean for Galaxy Y article.