Unified Extensible Firmware Interface (UEFI)

Unified Extensible Firmware Interface

For many years BIOS has been the industry standard for booting a PC. BIOS has served us well, but it is time to replace it with something better. UEFI is the replacement for BIOS, so it is important to understand the differences between BIOS and UEFI. In this section, you learn the major differences between the two and how they affect operating system deployment.

Introduction to UEFI

BIOS has been in use for approximately 30 years. Even though it clearly has proven to work, it has some limitations, including:

  • 16-bit code
  • 1 MB address space
  • Poor performance on ROM initialization
  • MBR maximum bootable disk size of 2.2 TB

As the replacement to BIOS, UEFI has many features that Windows can and will use.

With UEFI, you can benefit from:

  • Support for large disks. UEFI requires a GUID Partition Table (GPT) based disk, which means a limitation of roughly 16.8 million TB in disk size and more than 100 primary disks.
  • Faster boot time. UEFI does not use INT 13, and that improves boot time, especially when it comes to resuming from hibernate.
  • Multicast deployment. UEFI firmware can use multicast directly when it boots up. In WDS, MDT, and Configuration Manager scenarios, you need to first boot up a normal Windows PE in unicast and then switch into multicast. With UEFI, you can run multicast from the start.
  • Compatibility with earlier BIOS. Most of the UEFI implementations include a compatibility support module (CSM) that emulates BIOS.
  • CPU-independent architecture. Even if BIOS can run both 32- and 64-bit versions of firmware, all firmware device drivers on BIOS systems must also be 16-bit, and this affects performance. One of the reasons is the limitation in addressable memory, which is only 64 KB with BIOS.
  • CPU-independent drivers. On BIOS systems, PCI add-on cards must include a ROM that contains a separate driver for all supported CPU architectures. That is not needed for UEFI because UEFI has the ability to use EFI Byte Code (EBC) images, which allow for a processor-independent device driver environment.
  • Flexible pre-operating system environment. UEFI can perform many functions for you. You just need an UEFI application, and you can perform diagnostics and automatic repairs, and call home to report errors.
  • Secure boot. Windows 8 and later can use the UEFI firmware validation process, called secure boot, which is defined in UEFI 2.3.1. Using this process, you can ensure that UEFI launches only a verified operating system loader and that malware cannot switch the boot loader.

Versions

UEFI Version 2.3.1B is the version required for Windows 8 and later logo compliance. Later versions have been released to address issues; a small number of machines may need to upgrade their firmware to fully support the UEFI implementation in Windows 8 and later.

Hardware support for UEFI

In regard to UEFI, hardware is divided into four device classes:

  • Class 0 devices. This is the UEFI definition for a BIOS, or non-UEFI, device.
  • Class 1 devices. These devices behave like a standard BIOS machine, but they run EFI internally. They should be treated as normal BIOS-based machines. Class 1 devices use a CSM to emulate BIOS. These older devices are no longer manufactured.
  • Class 2 devices. These devices have the capability to behave as a BIOS- or a UEFI-based machine, and the boot process or the configuration in the firmware/BIOS determines the mode. Class 2 devices use a CSM to emulate BIOS. These are the most common type of devices currently available.
  • Class 3 devices. These are UEFI-only devices, which means you must run an operating system that supports only UEFI. Those operating systems include Windows 8, Windows 8.1, Windows Server 2012, and Windows Server 2012 R2. Windows 7 is not supported on these class 3 devices. Class 3 devices do not have a CSM to emulate BIOS.

Windows support for UEFI

Microsoft started with support for EFI 1.10 on servers and then added support for UEFI on both clients and servers.

With UEFI 2.3.1, there are both x86 and x64 versions of UEFI. Windows 10 supports both. However, UEFI does not support cross-platform boot. This means that a computer that has UEFI x64 can run only a 64-bit operating system, and a computer that has UEFI x86 can run only a 32-bit operating system.

How UEFI is changing operating system deployment

There are many things that affect operating system deployment as soon as you run on UEFI/EFI-based hardware. Here are considerations to keep in mind when working with UEFI devices:

  • Switching from BIOS to UEFI in the hardware is easy, but you also need to reinstall the operating system because you need to switch from MBR/NTFS to GPT/FAT32 and NTFS.
  • When you deploy to a Class 2 device, make sure the boot option you select matches the setting you want to have. It is common for old machines to have several boot options for BIOS but only a few for UEFI, or vice versa.
  • When deploying from media, remember the media has to be FAT32 for UEFI, and FAT32 has a file-size limitation of 4GB.
  • UEFI does not support cross-platform booting; therefore, you need to have the correct boot media (32- or 64-bit).

Allowing non-Administrators to control Hyper-V

By default Hyper-V is configured such that only members of the administrators group can create and control virtual machines.  I am going to show you how to allow a non-administrative user to create and control virtual machines.

Hyper-V uses the new authorization management framework in Windows to allow you to configure what users can and cannot do with virtual machines.

Hyper-V can be configured to store it’s authorization configuration in Active Directory or in a local XML file.  After initial installation it will always be configured to use a local XML file located at \programdata\Microsoft\Windows\Hyper-V\InitialStore.xml on the system partition.  To edit this file you will need to:

Open the Run dialog (launch it from the Start menu or press Windows Key + R).
Start mmc.exe
Open the File menu and select Add/Remove Snap-in…
From the Available snap-ins list select Authorization Manager.
Click Add > and then click OK.
Click on the new Authorization Manager node in the left panel.
Open the Action menu and select Open Authorization Store…
Choose XML file for the Select the authorization store type: option and then use the Browse… to open \programdata\Microsoft\Windows\Hyper-V\InitialStore.xml on the system partition (programdata is a hidden directory so you will need to type it in first).
Click OK.
Expand InitialStore.xml then Microsoft Hyper-V services then Role Assignments and finally select Administrator.
Open the Action menu and select Assign Users and Groups then From Windows and Active Directory…
Enter the name of the user that you want to be able to control Hyper-V and click OK.
Close the MMC window (you can save or discard your changes to Console 1 – this does not affect the authorization manager changes that you just made).

The user that you added will be able to completely control Hyper-V even if they are not an administrator on the physical computer.

Disk2vhd: New Utility to Create VHD Versions of Physical Disks

Disk2vhd” is a new utility released by Sysinternals team at Microsoft which allows you to create VHD versions of physical disks. If you are not aware of these technical terms, lets help you in understanding them.

VHD refers to “Virtual Hard Disk” which is a file format used in Microsoft virtual machines. So by using “Disk2vhd” you can create VHD versions of your HDD which can be used in Microsoft Virtual PC or Microsoft Hyper-V virtual machines (VMs).

http://img.photobucket.com/albums/v374/vishaal_here/Disk2VHD.png

Disk2vhd supports Windows XP SP2 and higher including 64-bit editions.

You can download it using following link:

Download Link

Hypervisor not running

I’m running Windows Server 2008 R2 on my laptop and after I Hyper-V role the following error message showed, when trying to start a Hyper-V machine. Seems the Hyper-Visor entry was never made to the BCD store.

To add the hypervisor auto launch into the BCD store you’ll need to run the following command in administrator mode

bcdedit /set hypervisorlaunchtype auto

make sure virtualization feature is enabled in BIOS!

wpeinit.exe Unable to Locate Component "wdi.dll"

so…. the problem seems to be VM Ware’s VM Server 1.0.4… (ESX/GSX) .. Could give some very “funny” problems when running a cluster with 1.0.3 and 1.0.4 nodes.. DOH!

Download the Intel e1000 drivers from http://downloadcenter.intel.com/Product_Filter.aspx?ProductID=1878&lang=eng for both XP and Vista. Put them in D:DriversIntel

using Windows AIK command prompt:

1.  In the command window, run copype x86 c:winpe to initialize my WinPE environment.

2.  Run the imagex /mountrw c:winpewinpe.wim 1 c:winpemount command to populate the image folder.

3.  Run the peimg /inf=D:DriversVMWarescsi*.inf /image=c:winpemount for all drivers (e.g. SCSI, NIC,etc.).

4.  Run the peimg /inf=D:DriversIntelPRO2KXP*.inf /image=c:winpemount for the Intel e1000 drivers.

5.  Add the ..WindowsSystem32wdi.dll from a Vista machine to the c:winpemountWindowsSystem32 folder.

6.  Run the imagex /unmount /commit c:winpemount to update the c:winpewinpe.wim.

7.  Run the oscdimg -n -h -bc:winpeetfsboot.com c:winpeiso c:winpewinpe.iso to generate the boot ISO file.
edit the *.vmx file to add the entry Ethernet0.virtualDev = “e1000” after Ethernet.preset = “TRUE” entry using Notepad.
The configure the VM to use WINPE.iso creating in Step 7.