The Hard Drive Firmware Uefi/bios and the Os Address
What is Unified Extensible Firmware Interface (UEFI)?
Unified Extensible Firmware Interface (UEFI) is a specification for a software programme that connects a computer’s
to its operating system (
). UEFI is expected to eventually supersede basic input/output system (
) but is compatible with information technology. The specification is virtually often pronounced past naming the messages U-E-F-I.
UEFI functions via special firmware installed on a estimator’s
motherboard. Similar BIOS, UEFI is installed at the time of manufacturing and is the first plan that runs when booting a computer. It checks to see which hardware components are attached, wakes up the components and hands them over to the OS. The new specification addresses several limitations of BIOS, including restrictions on hard deejay
size and the amount of time BIOS takes to perform its tasks.
About modernistic calculator systems are equipped to back up traditional BIOS, as well every bit UEFI, although Intel Corp. has stated its intention to stage out BIOS back up in newer personal computers (PCs).
What does UEFI exercise?
UEFI defines a new method by which OSes and platform firmware communicate, providing a lightweight BIOS culling that uses only the information needed to launch the Bone boot process. In addition, UEFI provides enhanced computer security features and supports nearly existing BIOS systems with
UEFI contains platform-related information tables and kicking and
service calls used by the Os loader. Taken together, this data defines the required interfaces and structures that must be implemented for firmware and hardware devices to back up UEFI. UEFI is programmable, enabling
original equipment manufacturer
developers to add together applications and drivers and UEFI to function as a lightweight OS.
In general, BIOS is considered a vestige from before computing, whereas UEFI is regarded every bit the wave of the hereafter. However, for ease of understanding, some information technology users refer to the processes collectively every bit
UEFI BIOS, despite their substantial differences.
UEFI’s evolution from EFI
BIOS has been in use since the advent of
computers in the mid-1970s. In 1981, IBM was the get-go vendor to comprise BIOS in PCs, a motility that prompted broad industry adoption. The emergence of UEFI parallels the increased bulldoze densities used for modern application workloads.
Intel adult the Extensible Firmware Interface (EFI) every bit an outgrowth of its 64-bit Itanium server architecture in the 1990s, a technology codeveloped with reckoner maker Hewlett Packard (HP). The industry perceived EFI equally a way to address the memory and processing limitations of BIOS in
server architectures. Those limitations included xvi-bit computing mode, bounded system retentivity and tedious assembly language programming.
EFI, after renamed Intel Boot Initiative, technically remains the property of Intel, although the vendor ceased sole development of the specification following the release of EFI version 1.ten in 2005. (By then, Intel had as well phased out its Itanium processor line, following product delays and other hiccups.) Intel contributed EFI 1.10 to the
UEFI Forum, an alliance of chipset, hardware, system, firmware and Os vendors.
The industry consortium manages the development of UEFI specification standards. The latest standard, UEFI ii.9, was made publicly bachelor in March 2021.
Booting upwardly: BIOS vs. UEFI
Turning on a calculator kick-starts a concatenation of events that occurs before the OS is loaded. Firmware rouses the estimator’southward subsystem to execute a series of tests and locates the
boot loader, which, in turn, starts the Os kernel.
BIOS and UEFI both use low-level software to manage startup functions prior to booting an Bone, albeit using different techniques.
BIOS resides on a chip on the machine’due south motherboard and initializes the central processing unit, random access memory, Peripheral Component Interconnect Express cards and network devices. BIOS runs a ability-on self-exam (Post) diagnostic sequence. POST ensures that hardware is configured properly and all components are functioning as intended.
BIOS runs only in xvi-chip processor mode, which limits the number of software commands the firmware is able to execute at any one fourth dimension. BIOS allots i megabyte of retentiveness in which tasks can exist executed. Interfaces and devices thus are initialized sequentially, which can contribute to a sluggish startup.
To reach its task, BIOS consults the Master Kicking Record (MBR) to locate the OS and launch the boot loader. MBR uses 32-scrap values to describe the offset and length of a segmentation, thus limiting BIOS systems to two terabyte (TB) drives and no more than four partitions.
UEFI behaves like a like a miniaturized OS that sits between firmware and the OS. It performs the same diagnostics as BIOS at startup just offers more flexibility. The Bone boots directly in UEFI. This eliminates the need to repeatedly press toggle keys, as is required to kick BIOS.
UEFI stores initialization information in an EFI file partition in
nonvolatile wink memory, rather than in the firmware. UEFI also can load during boot from a drive or a network share. UEFI besides deploys a more flexible partitioning scheme than MBR, known as a Globally Unique Identifier Partition Table, or GPT. GPT was also created past Intel as part of EFI. GPT uses 64-bit values to enable the creation of up to 128 partitions and is required for systems launched from 2 TB drives and larger. The EFI partition uses the
file allocation table, including FAT16, FAT32 or virtual FAT.
Most new desktop PCs, laptops and some tablets bundle UEFI firmware that runs in compatibility support fashion for older 32-bit Windows. Figurer manufacturers are expected to back up BIOS in the near term, merely the transition to UEFI is well underway. In 2013, custody of the Avant-garde Configuration and Power Interface (ACPI) was transferred to UEFI Forum.
Originally developed collaboratively by HP, Intel, Microsoft, Phoenix Technologies and Toshiba, ACPI is an open standard for BIOS that governs how much ability is delivered to each peripheral device.
Advantages of UEFI
UEFI provides many significant enhancements over BIOS, including the following:
Microsoft Windows users can run 32-bit UEFI or 64-bit UEFI, although experts recommend that the Os bit manner and the firmware chip fashion should exist the same to avoid communication issues during runtime.
According to UEFI Forum, UEFI supports boot drives of 2.2 TB and higher capacities, including drives with theoretical capacity of 9.4
zettabytes. That far exceeds the maximum drive capacities currently available.
UEFI supports detached drivers, whereas BIOS drive back up is stored in
read-only memory, which necessitates tuning it for compatibility when drives are swapped out or changes are made.
Graphical user interface (GUI).
UEFI enables new modules to be added to the GUI more easily, including device drivers for motherboard hardware and attached peripheral devices.
Multiple Os support.
Whereas BIOS allows a single kicking loader, UEFI lets users install loaders for
Debian-based Ubuntu and other Linux variants, along with Windows Bone loaders, in the same EFI organization partition.
UEFI firmware is written predominantly in
language, which enables users to add or remove functions with less programming than BIOS, which is written in an
linguistic communication, sometimes in combination with C.
Secure Boot is a UEFI protocol for Windows 8 or later on Windows versions. Secure Boot makes a organization’due south firmware the root of trust to verify device and system integrity. The goal is to prevent hackers from installing
in the time between bootup and handoff to the Bone. Secure Boot also enables an authorized user to configure networks and troubleshoot bug remotely, something a BIOS administrator must be physically present to do.
As computer makers gradually move abroad from BIOS, they typically integrate UEFI firmware that runs with Compatibility Back up Module (CSM) in modern devices. Although non intended equally a long-term solution, CSM enables UEFI-based machines to launch in legacy BIOS manner to work with older Windows versions and other OSes. All the same, users may find information technology preferable to upgrade to the latest version of the Os to realize the value of UEFI.
UEFI disadvantages, or when to boot from BIOS
Software is always a target for threat actors, and UEFI is no exception. Ane such attack, dubbed
TrickBot, surfaced in December 2020. TrickBot malware works by attempting to spy on device firmware, which could permit malicious actors to subvert the boot process and gain access to the OS.
came on the heels of 2018 findings by ESET Research, a Slovak outlet for the information security community, which claimed to have discovered a rootkit in the wild that potentially enabled hackers to surveil UEFI firmware and install malicious lawmaking.
Bated from security problems, organizations switching to UEFI may incur a cost related to booting from
wink. While this is faster than booting from
hard disk drives, older systems may require a retrofit, namely a larger flash die on the motherboard.
Another potential drawback is UEFI’s reliance on the Fatty file format, which is maintained by the Bone. Larger drive partitions tin can add too much system overhead, thus defeating some of the functioning advantages. This is an example in which BIOS can exist a more useful option, especially for a reckoner running an older Os version and smaller kick disks.
Users tin can download the UEFI specification from the UEFI Forum website. The almost recent version, UEFI 2.nine, features several enhancements, including the post-obit:
- supports devices based on the new
Compute Express Link
- supports publishing Linux Device Tree Blob binary format files that place computer components in the UEFI configuration table; and
- clarifies how UEFI-based update runtime calls are made on sure
Advanced Reduced Educational activity Set Calculating Auto server
To determine whether a calculator boots from BIOS or UEFI, press the
keys on the keyboard to launch the Run configuration box. Type
in the dialog box, and striking the
fundamental. A system summary screen appears. Await for the entry entitled
BIOS Mode, and brand note of the corresponding value. If the value says
Legacy, the system has BIOS. Otherwise,
will appear in the value field.
Windows users tin can access UEFI via the PC Settings pick in the search bar. The path is PC Settings > Update & Security > Recovery > Advanced Startup, and select the
option. From the bill of fare, select Troubleshoot > Advanced Options > UEFI Firmware Settings, and restart once again.
Linux machines with UEFI installed will bear witness it in the sys/firmware/efi directory. This will also be reflected in the Linux
Yard Unified Bootloader
boot manager every bit
grub-efi, rather than
Coreboot and UEFI
With the industry gradually phasing BIOS out, UEFI receives most of the attention as the heir credible. However, open source Coreboot is another option vying to replace legacy BIOS, and its proponents claim it is faster than UEFI. Coreboot, formerly known every bit LinuxBIOS, is purportedly able to supersede proprietary BIOS and UEFI firmware — with underlying benefits of farthermost performance, minimal resources to kick machines and security measures that include a minimal
trusted computing base
and virtual kicking deejay.
Coreboot code was offset introduced in 1999, and the community-based evolution project’s supporters include Google, whose
devices replaced BIOS with Coreboot since the outset generation. Coreboot’s market penetration has been slow, however, due to the piece of work it entails on the office of manufacturers. Since Coreboot initializes only Bare metal, device makers demand to make the effort to port the code for integration in chips and motherboards.