The Unified Extensible Firmware Interface UEFI [1] is a publicly available specification that defines a software interface between an operating system and platform firmware. UEFI can support remote diagnostics and repair of computers, even with no operating system installed. BIOS limitations such as bit real mode1MB addressable memory space, [7] assembly language programming, and PC AT hardware had become too restrictive for the larger server platforms Itanium was targeting.
Version 2. It added cryptography and security. The latest UEFI specification, version 2. The project promotes the idea of Firmware as a Service. In OctoberArm announced Arm ServerReadya compliance certification program for landing the generic off-the-shelf operating systems and hypervisors on Arm-based servers.
In OctoberArm announced the extension of the program to the edge and IoT market. The new program name is Arm SystemReady. Many Linux and BSD distros can support both recipes. Vmware workstation 14 uefi boot free download interface defined by the EFI specification includes data tables that contain platform information, and boot and runtime services that are available to the OS loader and OS. As of version 2. UEFI requires the firmware and operating system loader or kernel to be size-matched; for example, a bit UEFI firmware implementation can load only a bit operating system OS boot loader or kernel unless the CSM-based Legacy boot is used.
After the system transitions from "Boot Services" to "Runtime Services", the operating system kernel takes over. At this point, the kernel can change processor modes if it desires, but this bars usage of the runtime services unless the kernel switches back again.
This partition is not required if the system is UEFI-based because no embedding of the second-stage code is needed in that case. EFI defines two types of services: boot services and runtime services. Boot services are available only while the firmware owns the platform i.
Runtime services are still accessible while the operating system is running; they include services such as date, time and NVRAM access. EFI defines protocols as a set of software interfaces used for communication between two binary modules. All EFI drivers must provide services to others via protocols.
System firmware has an interpreter for EBC images. This allows the OS to rely on EFI for drivers to perform basic graphics and network functions before, and if, operating-system-specific drivers are loaded. In other cases, the EFI driver can be filesystem drivers that allow for booting from other types of disk vmware workstation 14 uefi boot free download. The EFI 1. UEFI 2. Most early UEFI firmware implementations were console-based.
Accessed by the UEFI firmware when a computer is powered up, it stores UEFI applications and vmware workstation 14 uefi boot free download files these applications need to run, including operating system boot loaders.
When a computer is powered on, the boot manager checks the boot configuration and based on its settings, then executes the specified OS boot loader or operating system kernel usually boot loader [53]. This automated detection relies on standardized file paths to the OS boot loader, with the path varying depending on the computer architecture. It is also common for a boot manager to have a textual user interface so the user can select the desired OS or setup utility from a list of available boot options.
In this scenario, booting is performed in the same way as on legacy BIOS-based systems, by ignoring the partition table and relying on the content of a boot sector. The UEFI 2. The mechanical details of how precisely these drivers are to be signed are not specified. Additional "key exchange keys" KEK can be added to a database stored in memory to allow other certificates to be used, but they must still have a connection to the private portion of the platform key.
Secure Boot is supported by Windows 8 and 8. Shell v1 should work in all UEFI systems. Methods used for launching UEFI shell depend vmware workstation 14 uefi boot free download the vmware workstation 14 uefi boot free download and model of the system motherboard. Some of them already provide a direct option in firmware setup for launching, e. Some other systems have an already embedded UEFI shell which can be launched by appropriate key press combinations.
The following is a list of commands supported by the EFI shell. Extensions to UEFI can be loaded from virtually any non-volatile storage device attached to the computer. This is the first stage of the UEFI boot but may have platform specific binary code that precedes it. It consists of minimal code written in assembly language for the specific architecture.
The second stage of UEFI boot consists of a dependency-aware dispatcher that loads and runs PEI modules PEIMs to handle early hardware initialization tasks such as main memory initialization and firmware recovery operations. This stage consist of C modules and a dependency-aware dispatcher. This is the stage between boot device selection and hand-off to the OS. TianoCore can be used as a payload for coreboot. Intel 's first Itanium workstations and servers, released inimplemented EFI 1. In JanuaryApple Inc.
Subsequent Macintosh models shipped with the newer firmware. Inmore x systems adopted UEFI. More commercially available systems are mentioned in a UEFI whitepaper.
With the release of Windows 8 in OctoberMicrosoft's certification requirements now require that computers include firmware that implements the UEFI specification. Furthermore, if the computer supports the " Connected Standby " feature of Windows 8 which allows devices to have power management comparable to smartphoneswith an almost instantaneous return from standby modethen the firmware is not permitted to contain a Vmware workstation 14 uefi boot free download Support Module CSM.
They may also change the default boot location. Numerous digital rights activists have protested against UEFI. Ronald G. Minnicha co-author of corebootand Cory Doctorowa digital rights activist, have criticized EFI as an attempt to remove the ability of vmware workstation 14 uefi boot free download user to truly control the computer. The development of coreboot requires cooperation from chipset manufacturers to provide the specifications needed to develop initialization drivers.
InMicrosoft announced that computers certified to run its Windows 8 operating system had to ship with Microsoft's public key enrolled and Secure Boot enabled. Microsoft denied that the Secure Boot requirement was intended to serve as a form of lock-inand clarified its requirements by stating that xbased systems certified for Windows 8 must allow Secure Boot to enter custom mode or be disabled, but not on systems using the ARM architecture.
Other developers raised concerns about the vmware workstation 14 uefi boot free download and practical issues of implementing support for Secure Boot on Linux systems in general. Former Red Hat developer Matthew Garrett noted that conditions in the GNU General Public License version 3 may prevent the use of the GNU GRand Unified Bootloader without a distribution's developer disclosing the private key however, the Free Software Foundation has since clarified its position, assuring that the responsibility to make keys available was held by the hardware manufacturer[] [] and that it would also be difficult for advanced users to build custom kernels that could function with Secure Boot enabled without self-signing them.
Several major Linux distributions have developed different implementations for Secure Boot. Garrett himself developed a minimal bootloader known as a shim, which is a precompiled, signed bootloader that allows the user to individually trust keys provided by Linux distributions. That also allows users to build their own kernels and use custom kernel modules as well, without the need to reconfigure the system.
Fedora also uses shim, [ which? It has been disputed whether the operating system kernel and its modules must be signed as well; while the UEFI specifications do not require it, Microsoft has asserted that their contractual requirements do, and that vmware workstation 14 uefi boot free download reserves the right to revoke any certificates used to sign code that can be used to compromise the security of the system. In Februaryanother Red Hat developer attempted to submit a patch to the Linux kernel that would allow it to parse Microsoft's authenticode signing using a master X.
However, the proposal was criticized by Linux creator Linus Torvaldswho attacked Red Hat for supporting Microsoft's control over the Secure Boot infrastructure. On 26 Marchthe Spanish free software development group Hispalinux filed a vmware workstation 14 uefi boot free download complaint with the European Commissioncontending that Microsoft's Secure Boot requirements on OEM systems were "obstructive" and anti-competitive.
At the Black Hat conference in Augusta group of security researchers presented a series of exploits in specific vendor implementations of UEFI that could be used to exploit Secure Boot. In August it was reported that two security researchers had found the "golden key" security key Microsoft uses in signing operating systems.
This allows any software to run as though it was genuinely signed by Microsoft and exposes the possibility of rootkit and bootkit attacks. This also makes patching the fault impossible, since any patch can vmware workstation 14 uefi boot free download replaced downgraded by the signed exploitable binary.
Microsoft responded in a statement that the vulnerability only exists in ARM architecture and Windows RT devices, and has released two patches; however, the patches do not and cannot remove the vulnerability, which would require key replacements in end user firmware to fix. The increased prominence of UEFI firmware in devices has also led to a number of technical problems blamed on their respective implementations.
Following the release of Windows 8 in late vmware workstation 14 uefi boot free download, it was discovered that certain Lenovo computer models with Secure Boot had firmware that was hardcoded to allow only executables named " Windows Boot Manager " or " Red Hat Enterprise Linux " to load, regardless of any other setting.
While potential conflicts with a kernel module designed to access system features on Samsung laptops were initially blamed also prompting kernel maintainers to disable the module on UEFI systems as a safety measureMatthew Garrett discovered that the bug was actually triggered by storing too many UEFI variables to memory, and that the bug could also be triggered under Windows under certain conditions. In conclusion, he determined that the offending kernel module had caused kernel message dumps vmware workstation 14 uefi boot free download be written to the firmware, thus triggering the bug.
From Wikipedia, the free encyclopedia. Operating system software specification. Main article: EFI system partition. See also: Secure Boot criticism. Retrieved 14 September The Register. Retrieved 24 September Archived from the original on 26 June Retrieved 6 March Retrieved on 30 October Retrieved 2 April Retrieved 11 December Intel still holds the copyright on the EFI 1.
There will be no future versions of the EFI specification, but customers who license it can still use it under the terms of their license from Intel. March Retrieved 23 May Retrieved 25 September
