bios uefi_什么是UEFI，它与BIOS有何不同？
bios uefi
The BIOS will soon be dead: Intel has announced plans to completely replace it with UEFI on all their chipsets by 2020. But what is UEFI, and how is it different from the BIOS we’re all familiar with?
BIOS即将失效：英特尔已宣布计划在2020年之前用所有芯片组上的UEFI完全替换它。但是UEFI是什么？它与我们都熟悉的BIOS有何不同？
Both UEFI and BIOS are low-level software that starts when you boot your PC before booting your operating system, but UEFI is a more modern solution, supporting larger hard drives, faster boot times, more security features, and—conveniently—graphics and mouse cursors.
UEFI和BIOS都是低级软件，可在启动操作系统之前在启动PC时启动，但是UEFI是一种更现代的解决方案，支持更大的硬盘驱动器，更快的启动时间，更多安全功能以及(方便地)图形和鼠标游标。
We’ve seen newer PCs that ship with UEFI still refer to it as the “BIOS” to avoid confusing people who are used to a traditional PC BIOS. Even if your PC uses the term “BIOS”, modern PCs you buy today almost certainly ship with UEFI firmware instead of a BIOS. Here’s why.
我们已经看到带有UEFI的较新PC仍将其称为“ BIOS”，以避免使习惯于传统PC BIOS的人感到困惑。 即使您的PC使用“ BIOS”一词，您今天购买的现代PC也几乎可以肯定带有UEFI固件而不是BIOS。 这就是为什么。
什么是BIOS？ (What Is a BIOS?)
BIOS is short for Basic Input-Output system. It’s low-level software that resides in a chip on your computer’s motherboard. The BIOS loads when your computer starts up, and the BIOS is responsible for waking up your computer’s hardware components, ensures they’re functioning properly, and then runs the bootloader that boots Windows or whatever other operating system you have installed.
BIOS是Basic Input-Output系统的缩写。 它是驻留在计算机主板上芯片中的低级软件。 BIOS在计算机启动时加载，BIOS负责唤醒计算机的硬件组件，确保它们正常运行，然后运行引导Windows或任何其他已安装操作系统的引导程序。
You can configure various settings in the BIOS setup screen. Settings like your computer’s hardware configuration, system time, and boot order are located here. You can access this screen by pressing a specific key—different on different computers, but often Esc, F2, F10, or Delete—while the computer boots. When you save a setting, it’s saved to the memory on your motherboard itself. When you boot your computer, the BIOS will configure your PC with the saved settings.
您可以在BIOS设置屏幕中配置各种设置。 诸如计算机的硬件配置，系统时间和启动顺序之类的设置位于此处。 您可以通过在计算机启动时按特定的键(在不同的计算机上有所不同，但通常是Esc，F2，F10或Delete)来访问此屏幕。 保存设置后，设置将保存到主板本身的内存中。 当您启动计算机时，BIOS将使用保存的设置来配置PC。
The BIOS goes through a POST, or Power-On Self Test, before booting your operating system. It checks to ensure your hardware configuration is valid and working properly. If something is wrong, you’ll see an error message or hear a cryptic series of beep codes. You’ll have to look up what different sequences of beeps mean in the computer’s manual.
在引导操作系统之前，BIOS将通过POST或开机自检。 它检查以确保您的硬件配置有效并且可以正常工作。 如果出现问题，您将看到错误消息或听到一系列神秘的哔声代码。 您必须在计算机手册中查找不同的哔哔声的含义。
When your computer boots—and after the POST finishes—the BIOS looks for a Master Boot Record, or MBR, stored on the boot device and uses it to launch the bootloader.
当您的计算机引导时(以及POST完成后)，BIOS会查找存储在引导设备中的主引导记录或MBR，并使用它来启动引导加载程序。
You may also see the acronym CMOS, which stands for Complementary Metal-Oxide-Semiconductor. This refers to the battery-backed memory where the BIOS stores various settings on the motherboard. It’s actually not accurate anymore, since this method has been replaced with flash memory (also referred to as EEPROM) in contemporary systems.
您可能还会看到首字母缩写词CMOS，它表示互补金属氧化物半导体。 这是指电池后备内存，BIOS在其中将各种设置存储在主板上。 实际上，它不再准确了，因为在现代系统中，该方法已被闪存(也称为EEPROM)所取代。
为什么BIOS过时 (Why the BIOS Is Outdated)
The BIOS has been around for a long time, and hasn’t evolved much. Even MS-DOS PCs released in the 1980s had a BIOS!
BIOS已经存在很长时间了，并且发展不多。 即使是1980年代发布的MS-DOS PC也具有BIOS！
Of course, the BIOS has evolved and improved over time. Some extensions were developed, including ACPI, the Advanced Configuration and Power Interface. This allows the BIOS to more easily configure devices and perform advanced power management functions, like sleep. But the BIOS hasn’t advanced and improved nearly as much as other PC technology has since the days of MS-DOS.
当然，BIOS会随着时间的发展而不断改进。 开发了一些扩展，包括ACPI，高级配置和电源接口。 这使BIOS可以更轻松地配置设备并执行高级电源管理功能，例如sleep 。 但是自从MS-DOS时代以来，BIOS并没有像其他PC技术一样进步和改进。
The traditional BIOS still has serious limitations. It can only boot from drives of 2.1 TB or less. 3 TB drives are now common, and a computer with a BIOS can’t boot from them. That limitation is due to the way the BIOS’s Master Boot Record system works.
传统的BIOS仍然存在严重的局限性。 它只能从2.1 TB或更小的驱动器启动。 3 TB驱动器现在很常见，带有BIOS的计算机无法从它们启动。 该限制是由于BIOS的主启动记录系统的工作方式而引起的。
The BIOS must run in 16-bit processor mode, and only has 1 MB of space to execute in. It has trouble initializing multiple hardware devices at once, which leads to a slower boot process when initializing all the hardware interfaces and devices on a modern PC.
BIOS必须在16位处理器模式下运行，并且只有1 MB的空间可以执行。BIOS难以一次初始化多个硬件设备，这导致在现代计算机上初始化所有硬件接口和设备时引导过程变慢。电脑
The BIOS has needed replacement for a long time. Intel started work on the Extensible Firmware Interface (EFI) specification back in 1998. Apple chose EFI when it switched to the Intel architecture on its Macs in 2006, but other PC manufacturers didn’t follow.
BIOS已需要更换很长时间了。 英特尔于1998年开始就可扩展固件接口(EFI)规范开展工作。苹果在2006年改用Mac上的Intel体系结构时选择了EFI，但其他PC制造商没有效仿。
In 2007, Intel, AMD, Microsoft, and PC manufacturers agreed on a new Unified Extensible Firmware Interface (UEFI) specification. This is an industry-wide standard managed by the Unified Extended Firmware Interface Forum, and isn’t solely driven by Intel. UEFI support was introduced to Windows with Windows Vista Service Pack 1 and Windows 7. The vast majority of computers you can buy today now use UEFI rather than a traditional BIOS.
在2007年，英特尔，AMD，微软和PC制造商就新的统一可扩展固件接口(UEFI)规范达成了一致。 这是由统一扩展固件接口论坛管理的行业范围内的标准，并非仅由英特尔推动。 Windows Vista Service Pack 1和Windows 7向Windows引入了UEFI支持。您现在可以购买的绝大多数计算机现在使用UEFI，而不是传统的BIOS。
UEFI如何在BIOS上进行替换和改进 (How UEFI Replaces and Improves on the BIOS)
UEFI replaces the traditional BIOS on PCs. There’s no way to switch from BIOS to UEFI on an existing PC. You need to buy new hardware that supports and includes UEFI, as most new computers do. Most UEFI implementations provide BIOS emulation so you can choose to install and boot old operating systems that expect a BIOS instead of UEFI, so they’re backwards compatible.
UEFI取代了PC上的传统BIOS。 在现有PC上无法从BIOS切换到UEFI。 与大多数新计算机一样，您需要购买支持并包括UEFI的新硬件。 大多数UEFI实现都提供BIOS仿真，因此您可以选择安装并引导希望使用BIOS而不是UEFI的旧操作系统，因此它们是向后兼容的。
This new standard avoids the limitations of the BIOS. The UEFI firmware can boot from drives of 2.2 TB or larger—in fact, the theoretical limit is 9.4 zettabytes. That’s roughly three times the estimated size of all the data on the Internet. That’s because UEFI uses the GPT partitioning scheme instead of MBR. It also boots in a more standardized way, launching EFI executables rather than running code from a drive’s master boot record.
此新标准避免了BIOS的限制。 UEFI固件可以从2.2 TB或更大的驱动器启动-实际上，理论上的限制是9.4 ZB。 这大约是Internet上所有数据的估计大小的三倍。 这是因为UEFI使用GPT分区方案而不是MBR 。 它还以更标准化的方式启动，启动EFI可执行文件，而不是运行驱动器主启动记录中的代码。
UEFI can run in 32-bit or 64-bit mode and has more addressable address space than BIOS, which means your boot process is faster. It also means that UEFI setup screens can be slicker than BIOS settings screens, including graphics and mouse cursor support. However, this isn’t mandatory. Many PCs still ship with text-mode UEFI settings interfaces that look and work like an old BIOS setup screen.
UEFI可以以32位或64位模式运行，并且具有比BIOS更多的可寻址地址空间，这意味着您的引导过程更快。 这也意味着UEFI设置屏幕可以比BIOS设置屏幕更流畅，包括图形和鼠标光标支持。 但是，这不是强制性的。 许多PC仍带有文本模式UEFI设置界面，其外观和工作方式类似于旧的BIOS设置屏幕。
UEFI is packed with other features. It supports Secure Boot, which means the operating system can be checked for validity to ensure no malware has tampered with the boot process. It can support networking features right in the UEFI firmware itself, which can aid in remote troubleshooting and configuration. With a traditional BIOS, you have to be sitting in front of a physical computer to configure it.
UEFI包含其他功能。 它支持安全启动，这意味着可以检查操作系统的有效性，以确保没有恶意软件篡改启动过程。 它可以支持UEFI固件本身中的联网功能，可以帮助进行远程故障排除和配置。 使用传统的BIOS，您必须坐在一台物理计算机之前进行配置。
It’s not just a BIOS replacement, either. UEFI is essentially a tiny operating system that runs on top of the PC’s firmware, and it can do a lot more than a BIOS. It may be stored in flash memory on the motherboard, or it may be loaded from a hard drive or network share at boot.
这也不只是BIOS的替代品。 UEFI本质上是一个运行在PC固件之上的微型操作系统，它的功能远不止BIOS。 它可能存储在主板上的闪存中，也可能在引导时从硬盘驱动器或网络共享中加载。
Different PCs with UEFI will have different interfaces and features. It’s all up to your PC manufacturer, but the basics will be the same on each PC.
具有UEFI的不同PC将具有不同的接口和功能。 这完全取决于您的PC制造商，但是每台PC的基本知识都是相同的。
如何在现代PC*问UEFI设置 (How to Access UEFI Settings on Modern PCs)
If you’re a normal PC user, switching to a computer with UEFI won’t be a noticeable change. Your new computer will boot up and shut down faster than it would have with a BIOS, and you can use drives of 2.2 TB or more in size.
如果您是普通PC用户，则使用UEFI切换到计算机不会有明显变化。 与使用BIOS相比，新计算机的启动和关闭速度更快，并且可以使用2.2 TB或更大容量的驱动器。
If you need to access low-level settings, there may be a slight difference. You may need to access the UEFI settings screen through the Windows boot options menu rather than pressing a key while your computer starts. With PCs now booting so quickly, PC manufacturers don’t want to slow down the boot process by waiting to see if you press a key. However, we’ve also seen PCs with UEFI that allow you to access the BIOS in the same way, by pressing a key during the boot-up process.
如果您需要访问低级设置，则可能会有细微的差别。 您可能需要通过Windows启动选项菜单访问UEFI设置屏幕，而不是在计算机启动时按任何键。 由于PC现在可以如此快速地启动，因此PC制造商不希望通过等待是否按某个键来减慢启动过程。 但是，我们还看到带有UEFI的PC允许您以相同的方式访问BIOS，方法是在启动过程中按一个键。
While UEFI is a big upgrade, it’s largely in the background. Most PC users will never notice—or need to care—that their new PCs use UEFI instead of a traditional BIOS. They’ll just work better and support more modern hardware and features.
尽管UEFI是一项重大升级，但它很大程度上是在后台进行的。 大多数PC用户永远不会注意到或需要关心他们的新PC使用UEFI而不是传统BIOS。 它们将更好地工作，并支持更多现代硬件和功能。
For more detailed information, read Adam Williamson of Red Hat’s explanation of how the UEFI boot process is different. You can also read the official UEFI FAQ.
有关更多详细信息，请阅读Red Hat关于UEFI引导过程如何不同的说明的Adam Williamson。 您也可以阅读官方UEFI常见问题解答。
Image Credit: Wikimedia Commons
图片来源： Wikimedia Commons
翻译自: https://www.howtogeek.com/56958/htg-explains-how-uefi-will-replace-the-bios/
bios uefi