Das U-Boot

Das U-Boot
U-Boot (which means “the submarine" in German) is a popular boot loader for ARM and PowerPC boards. This tools is maintained primarily by DENX Software is part of this company’s embedded Linux suite of products. This company contracts with hardware manufacturers to keep U-Boot up to date for their hardware, which means U-Boot is frequently the first boot loader ready for a large number of boards.

The sources are available via Git or using the FTP site. To download with Git, do the following:

$ cd ~
$ git clone git://git.denx.de/uboot.git u-boot

If you want to use a specific release of the software, download via FTP and unpack the compressed tar file. Substitute the version number for

in the commands:

$ wget ftp://ftp.denx.de/pub/u-boot/u-boot-.tar.bz2
$ tar xjf u-boot-.tar.bz2

After you download the sources, the building software works using the configure/build model. The project has configurations stored in theinclude/configs directory; to use the configuration, strip off the path, remove the training .h, and append _config to the remaining text. The include/configs
directory contains this file:

MPC8260ADS

To configure a U-Boot build for this board, do the following:

$ make MPC8260ADS_config

The software works a little while and shows a confirmation message indicating that the project was configured. If you’re working with several boards, be sure to clear the environment between configurations by doing the following to empty the build directory of any leftovers that could cause errors:

$ make distclean

Using U-Boot
U-Boot works like other boot loaders in that you load a kernel into memory and then run that image. The image loaded into memory can be stored on a server running TFTP or on a flash partition. You configure IP information in U-Boot by setting environment variables to configure the board’s and TFTP server’s address. To set the board’s IP address to 10.0.0.2 and the address of the TFTP server to 10.0.0.1, use the following commands:

=> setenv ipaddr 10.0.0.2
=> setenv serverip 10.0.0.1

The device is now configured so that it can communicate over the Ethernet adapter. To download a file from a TFTP server, use the tftpboot command

=> tftpboot 0x80000000 kernel

This loads the kernel into memory at the specified address and starts the booting process. The bootargs environment variable controls what kernel command-line parameters are sent during bootup. Setting bootargs works like setting the board’s IP address:

=> setenv bootargs root=/dev/mtd1 rootfstype=jffs2 init=theapp

To save the values of the environment variables, use the saveenv command. It writes the values of the current set of environment variables to flash so they’re present the next time U-Boot runs on the kboard.

Windows 7 Keyboard Shortcuts

Use the keyboard to switch between applications, launch Windows Explorer, lock your desktop, and access other handy features

The debate has long raged whether keyboard shortcuts or mouse clicks are a more efficient way to accomplish tasks, and of course the answer will usually come down to personal preference. However, if you’re using a laptop keyboard frequently, you might find some keyboard shortcuts essential. In this Top Ten column, I’ll share my favorite Windows 7 keyboard shortcuts. These shortcuts let you work quickly and efficiently with your Windows desktop. Although some of these shortcuts provide a quicker way to perform the same actions you’re able to perform using the mouse, others have no graphical equivalent. And while some of these shortcuts have been available in Windows Vista and Windows XP, others are brand new to Windows 7.

Windows key+Spacebar—The Windows key (Win)+ Spacebar keystroke combination gives you a quick way to display your desktop. All open Windows are made transparent, and you can see the desktop underneath. However, you can’t interact with anything on the desktop. When you release the Windows key, the open windows become visible again.


Win+Home—This keyboard shortcut provides a handy way to quickly clean up your workspace. Pressing Win+Home minimizes all open windows with the exception of the currently active window.


Win+Number—The Windows key plus a number provides a shortcut to opening items in the Windows 7 taskbar. Press the Windows key together with the number that corresponds to the taskbar item you want to open, counting left to right. For instance, Win+2 opens the second taskbar item.


Win+(+ or -)—This keyboard shortcut can be handy during presentations because it lets you magnify the screen. Pressing the Windows key and the plus sign (+) makes the entire screen larger with each iteration. Conversely, pressing the Windows key and the minus sign (-) makes the screen display progressively smaller.


Win+T—This keyboard shortcut is handy if you want to quickly scroll through the different items in the Windows 7 taskbar. Pressing Win+T cycles through the taskbar items, displaying the thumbnail image for each item. If you want to change which item you’re currently working in, you can press Enter when an item is highlighted to switch to that item.


Win+Left arrow and Win+Right arrow—Although some of these shortcuts have been in previous versions of Windows, these two are totally new to Windows 7. They let you take advantage of the UI’s side-by-side docking feature. Pressing the Windows key and either the Right or Left arrow key docks the current Window to the side of the desktop that corresponds with the direction of the arrow.


Win+L—This keyboard combination is super handy for quickly locking your desktop. Pressing Win+L locks the desktop and displays the Windows logon screen. To unlock the desktop, you need to enter your Windows password.


Win+E—Even faster than launching Windows Explorer by right clicking the Start button, pressing Win+E launches Windows Explorer, starting with the Computer view. From there, it’s easy to navigate through the system’s drives shown in the right portion of the Windows Explorer window to find whatever you’re looking for.


Win+P—If you’ve ever needed to give presentations on multiple brands of laptops, you know how annoying it can be to search each different type of laptop for its external projector or monitor hot key. Windows 7 fixes that problem. Pressing Win+P displays the Presentation Display Mode window, which lets you toggle your laptop’s presentation mode between Computer Only, Duplicate, Extended, or Projector Only.


Win+X—If you’re running Windows 7 on a laptop, this keyboard shortcut is for you. Pressing Win+X displays the Windows Mobility Center, which lets you control a number of system settings, including the audio level, the power scheme, wireless networking, external displays, and the external projector. The Windows Mobility Center is also often customized by each OEM.

Source of Information : Windows IT Pro June 2010

YAMON

YAMON is the boot loader used on MIPS development boards and is created and maintained by MIPS. Because YAMON is specific to MIPS development boards, it’s rarely rebuilt. The best thing to do is download the required binary from http://www.mips.com/products/system-software/yamon/. On this page is a link for the sources; to download them, you must register.2 YAMON is different in that it primarily uses S-records (frequently called SRECs) as its input format. An S-record file contains lines starting with the letter S (for “Start”), a number indicating the type of line, and the payload followed by a checksum. All the data in an SREC file is ASCII characters, making this format very easy to examine in a
text editor.

To download and run a kernel, do the following:

YAMON> load tftp:///
YAMON> go

 is the IP address of a host running TFTP, and 

is the SREC to download. Notice that the there’s no load address in this command; that information is encoded into the
SREC file.

Diskpart Exerts VHD Control

Manipulate virtual hard disks as if they’re actual physical disks

In “Diskpart Goes Virtual” (InstantDoc ID 103685), I showed you how to use Diskpart’s Create Vdisk command to build a Virtual Hard Disk (VHD) file. A VHD is a file that lets you easily package and transport data that can be mounted to act as a hard disk or, of course, used as a virtual disk with Microsoft’s virtualization tools. There’s more to using a VHD than creating it, however, so this month I’ll show you a few more VHD-related commands. Last month, you created a 200MB VHD named e:\test.vhd. Now that you have this VHD, you’d like to interact with it (e.g., examine its contents, put files in it), so you’ll need to use a couple more commands in Diskpart: Select Vdisk and Attach Vdisk. In our example, the Select Vdisk command and its results look like

DISKPART> select vdisk file=e:\test.vhd
DiskPart successfully selected the virtual disk file.

Select Vdisk doesn’t offer any options except noerr, an option available on most Diskpart commands that simply instructs Diskpart to keep running a script despite errors.

You still can’t look inside the VHD or create files in it, though. Once you’ve created and selected the VHD, you can use Attach Vdisk to instruct Windows to treat the VHD as if it were an actual physical disk. Its simplest syntax looks like

attach vdisk

Note that you don’t need file=<vhdfilename> parameters. Diskpart simply examines the virtual disk that you’ve just designated with the Select Vdisk command and instructs Windows that you’ve installed a new hard disk. You can now use commands such as Create Partition, Assign Letter, and Format to prepare the virtual disk for normal disk operations. Once your VHD has been selected, attached, partitioned, formatted, and given a letter, it’s almost indistinguishable from a physical hard disk.

When you’ve finished creating files and installing software on your VHD, you can instruct Windows to stop treating the VHD as an actual hard disk by typing two commands:

select vdisk file=vhdfilename
detach vdisk

We discussed the Create Vdisk command last month, but you probably won’t use that command nearly as often as you’ll use the Select Vdisk/Attach Vdisk and Select Vdisk/Detach Vdisk combinations. For example, if you have three already-created VHDs on your hard drive, you could type three Select Vdisk/Attach Vdisk command pairs and end up simultaneously working with three VHDs attached as three “imaginary” hard disks.

Suppose you sit down at a system that you know nothing about, and you see a surprising number of lettered volumes. You want to know how to determine which, if any, of the system’s hard drives are VHDs. If you’re working from a system with a full GUI, the easiest way to find the VHDs is to look at the drive icons in Logical Disk Manager (diskmgmt.msc); LDM colors VHDs cyan instead of the normal gray. If you don’t have a GUI to work with, you can use Diskpart’s List Vdisk command. On a system with two attached virtual disks.

Recall the List Disk command, which lists all the drives on a system. On a system with VHD support, List Disk lists only those drives that seem somewhat local. I say “somewhat local” because although mapped network drives aren’t listed, iSCSI LUNs are listed—and so are attached VHDs. Unfortunately, List Disk doesn’t offer much in the way of clues to a disk’s true nature, so you can’t quickly see which are iSCSI or VHD. You can always determine a disk’s nature by first selecting it (Select Disk disknumber), then typing Detail Disk. It will then report a disk type (e.g., iSCSI, Virtual). But that’s a pain, which is why List Vdisk is so likeable. The second column of List Vdisk’s results—Disk ###—refers to the disk number shown in the List Disk output. Nice!

Oh, and one more thing about attached VHDs in Windows: The attachment doesn’t survive a reboot, so if you’re going to need a VHD attached all the time, consider cooking up a Diskpart script for your logon or startup script. Happy attaching!

Source of Information : Windows IT Pro June 2010

System Center Data Protection Manager 2010

System Center Data Protection Manager (DPM) 2010 is the first major update to Microsoft’s data protection product since DPM 2007 SP1, and it expands on that product’s core functionality around protecting file shares, Exchange, Microsoft SQL Server, Microsoft SharePoint, and Hyper-V. Oriented to protecting only Microsoft workloads, DPM 2010 integrates with the core data storage technologies in each (such as Shadow Copies in Windows Server), and provides near-term restoration from disk and long-term restoration from tape. New 2010 features include these:

Cloud restore capabilities. Building on an exclusive offer that first appeared in DPM 2007 SP1, DPM 2010 supports replicating data to an Iron Mountain vault, extending the previous disk and tape restoration capabilities.

Client support. For the first time, DPM also supports client-based data protection. And for laptops and other clients that might be disconnected from the corporate network, DPM 2010 can create local shadow copies to a reserved area of the disk, then protect the data on the server when a connection is established to the network. DPM 2010 supports 1,000 clients per server and works with both Windows 7 and Windows Vista.

DPM 2010 will ship alongside SCE 2010 on June 1. If you’re interested in deploying both, Microsoft is offering a new Essentials Plus License that combines a single client management license for each into a single, less expensive package. Otherwise, pricing and licensing for SCE 2010 and DPM 2010 haven’t changed.

Source of Information : Windows IT Pro June 2010

System Center Essentials 2010

Although Microsoft cancelled its midmarket-focused Essential Business Server product line—I was told that customers appreciated the integrated management but not the requirement that they buy three to four servers at a time—it hasn’t lost focus on this small but important part of its customer base. Indeed, with Microsoft’s midmarket customers returning to mainstream Windows Servers and other Microsoft servers, they need good management tools. So, not surprisingly, the software giant is offering a new version of its midmarket management solution, called System Center Essentials 2010. SCE 2010 hits all the midmarket high points, providing automation and central management for the busy IT generalists that keep this market running—and if you’re familiar with the System Center family of products, you’ll understand why this is such a big deal. (Microsoft defines midmarket as mid-sized companies with up to 50 servers and 500 clients.) By the time you read this, the final release of SCE 2010 will have hit the streets on June 1, 2010. Here’s what you get.

Unified management of physical machines and VMs. SCE has always offered a unified management experience, but in SCE 2010 this has been enhanced with virtualization capabilities from Microsoft System Center Virtual Machine Manager (VMM), including the ability to manage physical and virtual servers and clients side by side, provisioning abilities, snapshots (which Microsoft calls Checkpoints), physical-to-virtual conversion, conversion from VMware to Hyper-V, machine migration, physical resource optimization, and more. This is the biggest improvement in SCE 2010 by far and represents an aggressive move into the virtualization space for this market segment. (Previously, Microsoft offered a bundle of the separate SCE 2007 SP1 and VMM 2008 tools.)

Monitoring and reporting. SCE’s monitoring capabilities help overworked IT staff in midsized businesses move from a reactive stance to being more proactive, while the reporting capabilities provide a running, high-level view of the health of the environment. The nicest thing about the UI, however, is that all of the status messages are hot links, providing not just information but actionable targets that can help admins fix problems. Embedded videos are attached to some links, helping admins learn on the go without leaving the SCE management environment.

Software deployment and update management. SCE 2010 builds off the deployment and update management capabilities from previous versions. There are many enhancements, and Microsoft offers a third-party catalog so that deployment and update functionality isn’t limited to its software. SCE 2010 offers more granular deployment and update management than before, so you can do things such as target machines that meet certain criteria (like 32-bit versions of Windows XP running particular languages). This is a nice solution for those seeking to deploy complex applications such as Office 2010.

Software and hardware inventory. As with its predecessors, SCE 2010 provides a complete asset inventory system for software and hardware in your environment. This helps with licensing compliance but also provides guidance when you want to upgrade to new OSs or applications. Additionally, while SCE 2007 shipped with a core set of management packs, SCE 2010 streamlines this and offers a more intelligent approach where only those management packs that apply to the software in your environment are surfaced. And unlike before, you can see these relevant new packs in the centralized management console rather than having to check the Microsoft website.

Source of Information : Windows IT Pro June 2010

Exchange 2010 SP1

Service packs are in the air, apparently. Despite Exchange 2010’s recent launch, Microsoft is already at work on SP1. Yes, Exchange 2010 SP1 will aggregate the product and security fixes that shipped since the product launched. But it will also include new capabilities, including better mail archiving, Outlook Web App (formerly Outlook Web Access) improvements, and better management functionality. Let’s look at these closely.

Mail archiving. Although Exchange 2010 includes integrated mail archiving capabilities, this feature is enhanced in SP1. It will offer the option to provision individual users’ personal archives to a different mailbox database other than their primary mailbox, import historic email from client-side PST files, and provide controls so that admins can delegate access to a user’s Personal Archive. A new multi-mailbox search feature will make it easier to find email for legal or regulatory reasons.

Outlook Web App. Microsoft’s web-based Exchange client is being updated again with a visual refresh, better performance through pre-fetching and asynchronous delete, the ability to mark as read and categorize operations, and public shared access to calendars. Some features from previous OWA versions are returning, too, like UI themes, and the ability for users to move the reading pane.

Management. With SP1, the Exchange Management Console (EMC) and Exchange Control Panel (ECP) are being enhanced to provide access to new management tasks, many of which relate to Retention Policy Tags that can help automate how email is deleted and archived. Other new features are coming in Exchange 2010 SP1 as well, and it’s starting to shape up as a major release. Microsoft expects to deliver it by the end of 2010.

Source of Information : Windows IT Pro June 2010

Windows HPC Server 2008 R2

Speaking of Windows Server, Microsoft is working to finalize Windows HPC Server 2008 R2. A public Beta 2 version is available now, and Microsoft hopes to ship the final version by the end of 2010. HPC Server 2008, formerly marketed as Windows Compute
Cluster Edition, is Microsoft’s entry in the very high-end highperformance computing (HPC) server market. HPC Server 2008 R2 is aimed at the most scalable server systems and provides parallel computing capabilities. Most exciting is its ability to run Microsoft Excel calculations in parallel on a cluster, providing the absolute best performance for scientists, engineers, and analysts.

Source of Information : Windows IT Pro June 2010

SP1 for Windows 7 and Windows Server 2008 R2

Microsoft announced something I’ve been dying to discuss: details about the first service pack for Windows 7 and Windows Server 2008 R2. (You might recall that both products are on the same code base and thus are serviced by the same service packs.) Last month, I noted that Windows 7 SP1 would mostly aggregate the software updates that appeared during its first year. However, Windows Server 2008 R2 SP1 will include some major new features:

Dynamic memory. Anyone comparing Microsoft’s Hyper-V virtualization platform and the VMware stack will conclude that Microsoft’s solution is evolving rapidly but lacking in a few key areas. Well, one of those remaining areas will be addressed with dynamic memory support in SP1. Dynamic memory makes it possible to pool the available memory on the host server and dynamically distribute it to virtual workloads as needed. In other words, you can dynamically allocate RAM to virtual machines (VMs), on the fly, without needing to shut them down first.

RemoteFX. This functionality—which came via Microsoft’s purchase of Calista—is now finally available via SP1. It enhances the display experience during RDP sessions, supporting Windows Aero, Microsoft Silverlight, and Adobe Flash user experiences, and 3D graphics. (Citrix is also partnering with Microsoft to integrate RemoteFX technologies into HDX for XenDesktop.) Microsoft hasn’t announced the timing of SP1, but the plan is to ship it one year after Windows 7 and Windows Server 2008 R2. And as you know, those products dropped in October 2009.

Source of Information : Windows IT Pro June 2010

Am I able to fit more RAM in my laptop?

So long as your laptop doesn’t already have the maximum capacity fitted, then you should indeed be able to add more memory (also known as RAM). Adding more
RAM is one of the best ways to increase your laptop’s performance, although it is by no means a magic formula. Unlike a desktop PC, a laptop generally only has two memory slots, which can also limit your options. The first thing you need to determine is how much memory your laptop already has, which you can do by right-clicking on My Computer and choosing Properties. You will see a summary of your laptop’s hardware, including the amount of RAM fitted. Now you need to find out how much can be fitted and what type you need. A good all-in-one resource for this is the Crucial Memory Advisor tool, available online at www.crucial.com/uk. Simply enter the manufacturer, product type and model name of your laptop, and you will be given all the details you need. Crucial also offers a free downloadable application called the Crucial System Scanner tool. This small app scans your system, saving you the time of identifying your exact model, and then tells you how much RAM you have, as well as how much you can fit, and then directs you to a web page to buy RAM.


Source of Information : Windows IT Pro June 2010

Can I replace my hard drive with an SSD?

SSDs, or Solid State Drives, offer a number of advantages over traditional hard drives. Laptop drives have always been slower than their desktop counterparts, and the hard drive can be one of the main bottlenecks in laptop performance. The main advantage of an SSD is one of speed, because the drives have no moving parts and are based on flash memory. Although the access speed of memory cards is not particularly quick, SSDs use optimised controller electronics to achieve high read and write speeds. A second advantage is that, again because there are no moving parts, SSDs are practically immune to knocks and bumps, making them particularly suitable for laptops. The disadvantages are that capacities are currently still pretty low, and they are very expensive.
That said, if you want to sacrifice capacity for speed then it’s certainly possible to. Unless you plan to reinstall Windows and all of your programs, you will need to back up all the data on your hard drive first. To do this, you will need a program such as DriveImage XML (www.runtime.org/driveimage-xml.htm) to copy the entire partition to an empty, removable hard drive. A laptop’s hard drive is usually located behind a panel on the underside of the laptop chassis, so remove the panel and slide the existing drive out. Slide the SSD drive in, use your Windows install or recovery disk to get a basic setup running, then copy the partition back from the removable drive.


Source of Information : Windows IT Pro June 2010

Can I print wirelessly from my laptop?

Why bother attaching cables when you can just as easily print via your wireless network instead? If you have another computer in the house that is connected to the printer, then you can simply set the printer up as a shared device and it should show up on the network automatically. You can then use the network browser on your laptop to add the printer to your list of printers. However, if you don’t have another PC, then things are slightly more complicated. While many wireless routers may have a USB port on the back, many of them are designed for connecting portable hard drives, and not printers. Your router must explicitly support a printer connection in order for you to connect it. The good news is that manufacturers are recognising that more people want to print wirelessly, so this is becoming a standard feature on many new routers. If your router doesn’t have a printercompatible USB port, then you can buy an adapter, either Wi-Fi or Bluetooth, which plugs into your printer. Not all laptops have Bluetooth built in and the range is also limited to about 10m. However, companies such as Belkin (www.belkin.co.uk) offer both types of adapter.



Source of Information : Windows IT Pro June 2010

To touch an Android

Archos releases compact Google-powered tablet

Adding to its existing range of compact tablet devices, Archos has announced the release of the Archos 7, a 7-inch device based around the Google Android operating system (OS) and designed for wireless internet and multimedia use at home or on the move. Weighing 350g and with a depth of just 12mm, it aims to provide comfortable mobility for the longest journeys, slipping easily into the smallest hand luggage With a claimed battery life of seven hours when playing video or a stunning 44 hours when playing music, there should be ample power to keep you entertained when you’re out and about and on long-haul journeys. The 7-inch screen features a resolution of 800 x 480 pixels and its touchscreen usability is designed to make it as easy as possible to control your music, movies and photos. With integrated Wi-Fi, you can also wirelessly browse the internet when in range of wireless hotspots. Driven by Google’s Android
OS, intuitive usability is promised, with full access to Android applications via the AppsLib online store. Available now, the Archos 7 is priced at £130 (inc. VAT).

MORE INFORMATION:
www.archos.com


Source of Information : What Laptop July 2010

JooJoo brings the magic

Stylish iPad rival unveiled for intuitive web browsing

With the Apple iPad now on sale in the UK, Fusion Garage has announced its own slate device – the JooJoo internet tablet. Claiming to be the world’s largest capacitive touchscreen device, it looks fantastic and bears more than a passing resemblance to its fruit-themed rival. Taking its name from the West African word for an object with magical powers, the 12.1-inch tablet is designed solely for smooth wireless internet browsing. With a claimed nine-second boot time and full gesture-control interface, it aims to make web use as seamless as possible. Built around a stylish aluminium chassis, the screen’s full gesture-control functionality makes it easy to scroll web pages and swipe between screens. While browsing the internet, a fullsize keyboard appears onscreen whenever text-entry is needed and disappears after use. Making it easier to access your favourite websites, the home page provides a customisable range of button links to popular sites such as Facebook, Flickr and YouTube. Fusion Garage also plans to follow Apple’s lead, with an online store to provide access to multiple web apps.
Core components include an Intel Atom processor, 1024MB of memory and a 4GB Solid State Drive. Wireless connectivity is provided by 801.11g Wi-Fi and Fusion Garage has added a feature currently missing from the iPad – a built-in 1.3-megapixel webcam. As well as a claimed five-hour battery life when using the Wi-Fi connection, an ambient light sensor automatically controls screen brightness and an accelerometer controls screen orientation. The JooJoo tablet is available now for £375 (inc. VAT) and looks like it could be a genuinely viable iPad rival.

MORE INFORMATION:
www.thejoojoo.com

Source of Information : What Laptop July 2010

Controlling Windows : The Window Manager

A window manager—the program that controls the look and feel of the basic GUI—runs under a desktop manager (such as GNOME or KDE) and controls all aspects of the windows in the X Window System environment. The window manager defines the appearance of the windows on the desktop and controls how you operate and position them: open, close, move, resize, minimize, and so on. It may also handle some session management functions, such as how a session is paused, resumed, restarted, or ended.

Window decorations. A window manager controls window decorations—that is, the titlebar and border of a window. Aside from the aesthetic aspects of changing window decorations, you can alter their functionality by modifying the number and placement of buttons on the titlebar.

The window manager takes care of window manipulation so client programs do not need to do so. This setup is very different from that of many other operating systems, and the way that GNOME deals with window managers is different from how other desktop environments work. Window managers do more than simply manage windows—they provide a useful, good-looking, graphical shell to work from. Their open design allows users to define their own policies, down to the fine details.

Theoretically GNOME is not dependent on any particular window manager and can work with any of several window managers. Because of their flexibility, you would not see major parts of the desktop environment change if you were to switch from one window manager to another. A desktop manager collaborates with the window manager to make your work environment intuitive and easy to use. Although the desktop manager does not control window placement, it does get information from the window manager about window placement.


Fedora/RHEL Window Managers
Metacity and Compiz—the default window managers for GNOME—provide window management and start many components through GNOME panel objects. They also communicate with and facilitate access to other components in the environment. The Desktop Effects window allows you to switch between Metacity and Compiz.

Using the standard X libraries, programmers have created other window managers, including blackbox, fluxbox, and WindowMaker. You can use yum to install any of these packages.


Source of Information : Prentice Hall A.Practical Guide to Fedora and Red Hat Enterprise Linux 5th Edition

Controlling Windows : Changing the Resolution of the Display

The X server starts at a specific display resolution and color depth. Although you can change the color depth only when you start an X server, you can change the resolution while the X server is running. The number of resolutions available depends both on the display hardware and on the configuration of the X server. Many users prefer to do most of their work at a higher resolution but might want to switch to a lower resolution for some tasks, such as playing games. You can switch between display resolutions by pressing either CONTROL-ALT-KEYPAD-+ or CONTROL-ALT-KEYPAD- –, using the + and – on the keyboard’s numeric keypad. You can also use the Monitor Resolution Settings window (Main menu: System -> Preferences -> Display) to change the resolution of the display.

Changing to a lower resolution has the effect of zooming in on the display; as a result, you may no longer be able to view the entire workspace at once. You can scroll the display by pushing the mouse pointer against the edge of the screen.


Source of Information : Prentice Hall A.Practical Guide to Fedora and Red Hat Enterprise Linux 5th Edition

Controlling Windows : Changing the Input Focus

When you type on the keyboard, the window manager directs the characters you type somewhere, usually to a window. The active window is the window accepting input from the keyboard; it is said to have the input focus. Depending on how you set up your account, you can use the mouse in one of three ways to change the input focus:

• Click-to-focus (explicit focus)—Gives the input focus to a window when you click the window. That window continues to accept input from the keyboard regardless of the location of the mouse pointer. The window loses the focus when you click another window. Although clicking the middle or right mouse button also activates a window, use only the left mouse button for this purpose; other buttons may have unexpected effects when you use them to activate a window.

• Focus-follows-mouse (sloppy focus, enter-only, or focus-under-mouse)— Gives the input focus to a window when you move the mouse pointer onto the window. That window maintains the input focus until you move the mouse pointer onto another window, at which point the new window gets the focus. When you move the mouse pointer off a window and onto the root window, the window that had the input focus does not lose it.

• Focus-strictly-under-mouse (enter-exit focus)—Gives the input focus to a window when you move the mouse pointer onto the window. That window maintains the input focus until you move the mouse pointer off the window, at which point no window has the focus. When you move the mouse pointer off a window and onto the root window, the window that had the input focus loses it, and input from the keyboard is lost.

You can use the Window Preferences window to change the focus policy. Under Fedora, you must install the control-center-extra package before you can display this window. To display this window, select Main menu: System -> Preferences -> Windows or give the command gnome-window-properties from a terminal emulator or Run Application window (ALT-F2). Put a tick in the check box next to Select windows when the mouse moves over them to select the focusfollows- mouse policy. When there is no tick in this check box, click-to-focus is in effect. Click Close. Focus-strictly-under-mouse is not available from this window.

To determine which window has the input focus, compare the window borders. The border color of the active window is different from the others or, on a monochrome display, is darker. Another indication that a window is active is that the keyboard cursor is a solid rectangle; in windows that are not active, the cursor is an outline of a rectangle.

Use the following tests to determine which keyboard focus method you are using. If you position the mouse pointer in a window and that window does not get the input focus, your window manager is configured to use the click-to-focus method. If the border of the window changes, you are using the focus-follows-mouse or focusstrictly-under-mouse method. To determine which of the latter methods you are using, start typing something, with the mouse pointer positioned on the active window. Then move the mouse pointer over the root window and continue typing. If characters continue to appear within the window, you are using focus-followsmouse; otherwise, you are using focus-strictly-under-mouse.


Source of Information : Prentice Hall A.Practical Guide to Fedora and Red Hat Enterprise Linux 5th Edition

What to Do If You Cannot Log In

If you enter either your username or your password incorrectly, the system displays an error message after you enter both your username and your password. This message indicates that you have entered either the username or the password incorrectly or that they are not valid. It does not differentiate between an unacceptable username and an unacceptable password—a strategy meant to discourage unauthorized people from guessing names and passwords to gain access to the system.

Following are some common reasons why logins fail:

• The username and password are case sensitive. Make sure the CAPS LOCK key is off and enter your username and password exactly as specified or as you set them up.

• You are not logging in on the right machine. The login/password combination may not be valid if you are trying to log in on the wrong machine. On a larger, networked system, you may have to specify the machine you want to connect to before you can log in.

• Your username is not valid. The login/password combination may not be valid if you have not been set up as a user.

• A filesystem is full. When a filesystem critical to the login process is full, it may appear as though you have logged in successfully, but after a moment the Login screen reappears. You must boot the system in rescue mode and delete some files.

• The account may be disabled. The root account is disabled from a GUI login by default. An administrator may disable other accounts. Often the root account is not allowed to log in over a network. You must use su or sudo if you need to work with root privileges from a remote system.


Source of Information : Prentice Hall A.Practical Guide to Fedora and Red Hat Enterprise Linux 5th Edition

Using the Internet to Get Help

The Internet provides many helpful sites related to Linux. Aside from sites that offer various forms of documentation, you can enter an error message from a program you are having a problem with in a search engine such as Google (www.google.com, or its Linux-specific version at www.google.com/linux). Enclose the error message within double quotation marks to improve the quality of the results. The search will likely yield a post concerning your problem and suggestions about how to solve it.

Red Hat Web sites. The Red Hat and Fedora Web sites are rich sources of information. The following list identifies locations that may be of interest:

• Fedora documentation is available at docs.fedoraproject.org.

• Manuals for Red Hat Linux through Linux 9 and RHEL are available at www.redhat.com/docs.

• Various types of support documents and support are available at www.redhat.com/apps/support (requires free registration).

• You can query the Red Hat Knowledgebase at kbase.redhat.com.

• The home pages for Fedora (fedoraproject.org) and RHEL (www.redhat.com) have a wealth of information.

• Fedora/RHEL support forums are online discussions about any Red Hat–related issues that people want to raise. One forum is dedicated to new users; others to Apache, the X Window System, and so on. Go to www.redhat.com/mailman/listinfo to browse the lists. Another site that has similar, useful information is fedoraforum.org.

• The Fedora/RHEL bugs database is available at bugzilla.redhat.com. Anyone can search the database. To submit new bugs or append to existing bugs, you need to sign up for a free account.

• Fedora weekly news is available at fedoraproject.org/wiki/FWN.

• RHEL hardware help is available from the Red Hat hardware catalog at hardware.redhat.com. The hardware that Fedora supports is mostly a superset of that supported by RHEL.


Source of Information : Prentice Hall A.Practical Guide to Fedora and Red Hat Enterprise Linux 5th Edition

GNOME Desktop Terminology

The following terminology, which is taken from the GNOME Users Guide, establishes a foundation for discussing the GNOME desktop.

Desktop. The desktop comprises all aspects of the GNOME GUI. While you are working with GNOME, you are working on the desktop. There is always exactly one desktop.


Panels. Panels are bars that appear on the desktop and hold (panel) objects. Initially there are two gray panels: one along the top of the screen (the Top Edge panel, or just Top panel) and one along the bottom (the Bottom Edge panel, or just Bottom panel). You can add and remove panels. You can place panels at the top, bottom, and both sides of the desktop, and you can stack more than one panel at any of these locations. The desktop can have no panels, one panel, or several panels.


Panel objects. Panel objects appear as words or icons on panels. You can click these objects to display menus, run applets, or launch programs. The five types of panel objects are applets, launchers, buttons, menus, and drawers. See page 113 for more information on panel objects.


Windows. A graphical application typically runs within and displays a window. At the top of most windows is a titlebar you can use to move, resize, and close the window. The root window is the unoccupied area of the workspace and is frequently obscured. The desktop can have no windows, one window, or many windows. Although most windows have decorations, some, such as the Logout window, do not.


Workspaces. Workspaces divide the desktop into one or more areas, with one such area filling the screen at any given time. Initially there are two workspaces. Because panels and objects on the desktop are features of the desktop, all workspaces display the same panels and objects. By default, a window appears in a single workspace. The Switcher enables you to display any one of several workspaces.


Tooltips. Tooltips is a minicontext help system that you activate by moving the mouse pointer over a button, icon, window border, or applet (such as those on a panel) and allowing it to hover there. When the mouse pointer hovers over an object, GNOME displays a brief explanation of the object.


Source of Information : Prentice Hall A.Practical Guide to Fedora and Red Hat Enterprise Linux 5th Edition

The C Programming Language

Ken Thompson wrote the UNIX operating system in 1969 in PDP-7 assembly language. Assembly language is machine dependent: Programs written in assembly language work on only one machine or, at best, one family of machines. The original UNIX operating system therefore could not easily be transported to run on other machines (it was not portable).

To make UNIX portable, Thompson developed the B programming language, a machine-independent language, from the BCPL language. Dennis Ritchie developed the C programming language by modifying B and, with Thompson, rewrote UNIX in C in 1973. The revised operating system could be transported more easily to run on other machines.

That development marked the start of C. Its roots reveal some of the reasons why it is such a powerful tool. C can be used to write machine-independent programs. A programmer who designs a program to be portable can easily move it to any computer that has a C compiler. C is also designed to compile into very efficient code. With the advent of C, a programmer no longer had to resort to assembly language to get code that would run well (that is, quickly—although an assembler will always generate more efficient code than a high-level language).

C is a good systems language. You can write a compiler or an operating system in
C. It is highly structured but is not necessarily a high-level language. C allows a programmer to manipulate bits and bytes, as is necessary when writing an operating system. But it also has high-level constructs that allow efficient, modular programming.

In the late 1980s the American National Standards Institute (ANSI) defined a standard version of the C language, commonly referred to as ANSI C or C89 (for the year the standard was published). Ten years later the C99 standard was published; it is mostly supported by the GNU Project’s C compiler (named gcc). The original version of the language is often referred to as Kernighan & Ritchie (or K&R) C, named for the authors of the book that first described the C language.

Another researcher at Bell Labs, Bjarne Stroustrup, created an object-oriented programming language named C++, which is built on the foundation of C. Because object-oriented programming is desired by many employers today, C++ is preferred over C in many environments. Another language of choice is Objective-C, which was used to write the first Web browser. The GNU Project’s C compiler supports C, C++, and Objective-C.


Source of Information : Prentice Hall A.Practical Guide to Fedora and Red Hat Enterprise Linux 5th Edition

Linux Is Portable

A portable operating system is one that can run on many different machines. More than 95 percent of the Linux operating system is written in the C programming language, and C is portable because it is written in a higher-level, machine-independent language. (The C compiler is written in C.)

Because Linux is portable, it can be adapted (ported) to different machines and can meet special requirements. For example, Linux is used in embedded computers, such as the ones found in cellphones, PDAs, and the cable boxes on top of many TVs. The file structure takes full advantage of large, fast hard disks. Equally important, Linux was originally designed as a multiuser operating system—it was not modified to serve several users as an afterthought. Sharing the computer’s power among many users and giving them the ability to share data and programs are central features of the system.

Because it is adaptable and takes advantage of available hardware, Linux runs on many different microprocessor-based systems as well as mainframes. The popularity of the microprocessor-based hardware drives Linux; these microcomputers are getting faster all the time, at about the same price point. Linux on a fast microcomputer has become good enough to displace workstations on many desktops. Linux benefits both users, who do not like having to learn a new operating system for each vendor’s hardware, and system administrators, who like having a consistent software environment.

The advent of a standard operating system has aided the development of the software industry. Now software manufacturers can afford to make one version of a product available on machines from different manufacturers.

Source of Information : Prentice Hall A.Practical Guide to Fedora and Red Hat Enterprise Linux 5th Edition