查看“启动屏幕”的源代码

启动屏幕通常由操作系统或其他软件显示，以直观地指示其初始加载过程，并提供系统已成功初始化的视觉确认。根据软件的不同，屏幕中可能包括版本信息、确定或不确定的进度指示器或状态消息。许多启动屏幕还包括加载软件的品牌、其开发人员和/或分销商的品牌。

==Windows==
===16 位 Windows===
在早期版本的 Windows 中，启动屏幕是一个与设备相关的独立模块，用于处理徽标绘制和动画。徽标模块存储在安装磁盘上的 <code>.LGO</code> 文件在安装过程中与设备无关的 <code>WIN.CNF</code> 组件组合在一起，形成 <code>WIN.COM</code> 启动器，允许 OEM 根据需要提供自己的徽标代码。第一个已知使用启动屏幕的版本是 [[Windows 1.0 Beta Release]]，它具有合并的 Microsoft 徽标和版本信息。在 [[Windows 1.04]] 之前，此屏幕在零售版本中几乎没有变化，当时 Microsoft 徽标已更新为 1987 徽标。

在 [[Windows 2.x]] 中，徽标位图和文本被分隔为单独的公共 <code>.LGD</code> 文件，它仍然与其他部分组合成 <code>WIN.COM</code>。[[Windows 3.0]] 及更高版本的 16 位版本仍保留相同的系统，尽管启动屏幕本身已更改为存储为 RLE 压缩位图的图形静止图像。

<gallery>
Windows-1.01-Boot.png|[[Windows 1.01]]
Win21386bootscreen.png|[[Windows/386 2.1]]
Win30rc6boot.png|[[Windows 3.00|Windows 3.0]]
Windows-3.1.103-Boot.png|[[Windows 3.1 Build 103|Windows 3.1]]
</gallery>

===Windows 9x===
[[Windows 95]] 引入了一个新的启动屏幕，该屏幕在 VGA 256 色模式下运行，并在运行时更改调色板末尾的保留条目以显示动画。在大多数版本中，主引导徽标以压缩形式包含在 <code>IO.SYS</code> 中，尽管可以通过将自定义徽标保存为引导驱动器根目录中的 <code>LOGO.SYS</code> 来使用自定义徽标。同样的方法也可用于“关机”（<code>LOGOW.SYS</code>）和“安全关机”（<code>LOGOS.SYS</code>）屏幕。在所有情况下，徽标文件的大小必须为 320×400 像素，并且应另存为 RLE 压缩位图。

早期的版本使用了让人想起“Flying Windows”屏幕保护程序的动画，Windows 徽标以随机颜色随机点亮整个屏幕。这是通过徽标位图实现的，该位图包含许多 Windows 标志，每个标志都使用与保留区域不同的颜色。通常，保留的条目将设置为黑色，引导动画代码将它们设置为颜色以实现效果。

从 [[Windows 95 Build 337|Build 337]] 开始，动画已更改为仅旋转保留的调色板条目，该条目用于后续 beta 版本中的滚动箭头效果，以及最终版本中的旋转渐变条，以及用于 Windows 95 和早期 [[Windows 98]] 版本中第一个启动屏幕的呼吸 Windows 徽标动画。

由于对实模式 MS-DOS 子系统进行了更改，[[Windows Me]] 在 Beta 2 之前完全没有启动屏幕。

<gallery>
Windows95-4.0.58s-Boot.png|[[Windows 95 Build 58s]]
Windows95-4.0.189-Boot.png|[[Windows 95 Build 189]]
Windows95-4.0.337-Boot.png|[[Windows 95 Build 337]]
Windows95-4.0.342-Boot.png|[[Windows 95 Build 342]]
Win95Boot.png|[[Windows 95 Build 950 r-6|Windows 95 RTM]]
WinMemphisBoot.png|[[Windows 98 Build 1351]]
</gallery>

===Windows NT===
[[Windows NT 3.1 Build 196|Build 196]] 是唯一不使用传统启动过程的可用版本，在启动时在浅灰色背景上显示带有深色文本的文本屏幕。与任何后来的版本不同，这个引导屏幕似乎主要由引导加载程序处理，它在加载内核二进制文件时在屏幕上打印其版本信息。然后，当内核开始执行时，屏幕将被清除，并被一行充满等号的行所取代。还可以修补引导加载程序，以在引导时显示有关加载的内核映像的详细信息。

在 [[Windows NT 3.1 1991 年 10 月版本|1991 年 10 月的版本]]中，引导屏幕在内核本身中重新实现。作为此更改的一部分，配色方案已更改为蓝色背景上的白色文本，这与新引入的[[蓝屏死机]]相匹配，并被选中以匹配 MIPS 固件显示以及许多 NT 开发人员使用的 SlickEdit 文本编辑器的默认配色方案。启动屏幕现在显示操作系统版本和内存量信息，并且还兼作早期用户模式进程的控制台。在 IBM 兼容的系统上，引导屏幕最初使用 25 行文本模式，尽管后来从 [[Windows NT 3.1 Build 475.1|Build 475]] 开始更改为 50 行。[[Windows NT 3.5]] 后来更新了启动屏幕，以始终显示处理器数，因为以前仅在使用多处理器内核时显示。

最后一个已知支持操作文本模式显示的版本是 [[Windows 2000 Build 1814.1]]，尽管自引入 <code>bootvid.dll</code> 驱动程序以来，它已被默认禁用，并且必须使用 <code>/NOGUIBOOT</code> 内核开关启用；在后续版本中，交换机将完全禁用启动屏幕，仅显示光标闪烁的空白屏幕。即使在 [[Windows 2000]] 引入图形启动屏幕之后，启动时文本控制台本身仍被保留，尽管在图形模式下重新实现，并且每当早期启动过程想要将某些内容打印到屏幕上时都会使用。在 [[Windows 7]] 及更早版本中，<code>/SOS</code> 内核开关完全禁用启动动画，并将版本和系统信息打印到控制台，类似于 [[Windows NT 4.0]]。

<gallery>
196-boot.png|[[Windows NT 3.1 Build 196]]
Windows_NT_Oct91_(2).png|[[Windows NT 3.1 1991 年 10 月版本]]
WindowsNT3.1-RTM-Boot.png|[[Windows NT 3.1 Build 511.1|Windows NT 3.1 RTM]]
WindowsNT35-3.5.807-Boot.png|[[Windows NT 3.5 Build 807.1|Windows NT 3.5 RTM]]
</gallery>

===Windows 2000 到 Vista===
[[Windows 2000 Build 1796.1|Build 1796]] 是首个包含用于启动时图形的 <code>bootvid.dll</code> 驱动程序的已知版本。这允许实现一个新的图形启动屏幕，该屏幕以 640×480 分辨率和 16 种颜色运行，并具有操作系统徽标以及渐变条和显示启动过程进度的确定进度条。后来的版本通过为渐变栏引入旋转动画、为启动时文本控制台添加单独的设计或为专业版和服务器版使用不同的图形来完善启动过程。最初，启动屏幕呈现在一个较小的中心窗口中，周围环绕着颜色填充，尽管后来它被重新设计以覆盖整个屏幕。

[[Windows Codename Neptune]] 中的启动加载程序似乎已使用代码进行了扩展，以便在从休眠状态恢复计算机或启用快速启动功能时呈现启动屏幕，从而替换旧版本和新版本显示的文本模式进度屏幕。该功能显然尚未完成，因为按 {{key press|Esc}} 键会暂停该过程，但不显示任何允许用户选择下一步操作的界面。旋转条动画也未实现。这后来演变为 <code>/BOOTLOGO</code> 启动开关，它允许用户指定自定义静态启动屏幕。

在 [[Windows XP]] 的开发过程中，启动动画设计进一步发展，尽管服务器版本在 Beta 2 之前继续使用较旧的 Windows 2000 设计。Windows 2000 启动屏幕的浅色背景被黑色取代，大概是为了隐藏一开始慢慢绘制的屏幕。确定进度条也被删除，尽管用于报告进度的代码仍然存在于启动代码中。Beta 1 版本中包含的第一个新设计以白色 Whistler 标志为特色，以及一个充满圆点的动画条。这在 Beta 2 版本中被一种设计所取代，该设计还有白色 Whistler 徽标，尽管是单色的，但带有与 Windows 徽标颜色相对应的四个色条的呼吸动画。Beta 2 设计有两种变体，其中一种具有较旧的 Windows 徽标，而另一种具有新徽标。

在 Beta 2 之后，启动屏幕再次更新，以反映 Windows XP 名称的引入。最初的设计以新的塑料 Windows XP 标志为特色，有一个呼吸的“loading...”标签，尽管它很快被最终的旋转条动画所取代。版本品牌和不同的动画颜色最初用于区分每个版本，但是，自 Service Pack 2 以来，所有版本最终都使用完全相同的启动屏幕。[[Windows Server 2003]] 和 [[Windows Vista]] 仍然使用整个 Windows XP 启动屏幕设计，尽管品牌不同，动画元素的设计也更新了。后者还包括由引导加载程序显示的备用启动屏幕，可以通过禁用 GUI 引导来启用，并且由静态极光图形和下面的 “Starting Windows Vista...”标签组成。

<gallery>
Windows2000-5.0.1796-Boot.png|[[Windows 2000 Build 1796.1]]
Win2000Boot.png|[[Windows 2000 Build 2195.1|Windows 2000 RTM]]
Whistler22672416Boot.png|[[Windows XP Build 2296.1.beta1.001024-1157|Windows XP Beta 1]]
2419-Boot.png|[[Windows XP Build 2419.1.idx02.010113-1154|Windows XP Build 2419]]
Whistler24282469Boot.png|[[Windows XP Build 2462.0.main.010315-1739|Windows XP Beta 2]]
Whistler24742475Boot.png|[[Windows XP Build 2474.0.main.010508-1907|Windows XP Build 2474]]
WindowsXPRTMBoot.png|[[Windows XP Build 2600.0.xpclient.010817-1148|Windows XP RTM]]
WinXPHomeBoot.png|[[Windows XP Build 2600.0.xpclient.010817-1148|Windows XP RTM]]（Home Edition）
Win2k3RTMBoot.png|[[Windows Server 2003 Build 3790.0.srv03_rtm.030324-2048|Windows Server 2003]]
WindowsVista-RTM-Boot.png|[[Windows Vista Build 6000.16386.vista_rtm.061101-2205|Windows Vista]] 
</gallery>

===Windows 7 及更高版本===
[[Windows 7 build 6469]] replaces the alternate boot screen enabled by disabling GUI boot with the logo of the Windows 7 project, although the default boot animation remains unchanged. A new boot screen routine was introduced in later builds, which now runs in 1024×768 resolution at true color,{{efn|The older Windows Vista boot screen is used if the system does not support the resolution or if the user decides to disable the newer boot screen by setting the BCD variable <code>graphicsmodedisabled</code> to <code>yes</code>.}} as well as allowed it to include localizable text. The new boot screen is also rendered cooperatively by both the boot loader and the kernel, which made it possible to display it when restoring Windows from hibernation as well. On regular boot, the first frame is drawn by the boot loader, while the rest of the animation is drawn by the kernel after it starts executing, which results in a slight delay before the animation starts. When restoring from hibernation or during a hybrid boot, the animation is drawn by the boot loader for the duration of the restoration process. In certain localizations, setup displays the boot screen as seen in the English version for 1-2 seconds before switching to the Windows Vista boot screen.

The Windows 7 team went through several design iterations for the actual boot screen animation. Early designs reused the Windows Vista aurora aesthetic with different animations, which included an indeterminate marquee animation of a spark in the Vista aurora graphic used by [[Windows 7 build 6519|build 6519]], or a recreation of the progress screen at login with the Aero waiting cursor and various status messages next to it used in [[Windows 7 build 6730|build 6730]]. Yet another design is used by [[Windows 7 build 6780|build 6780]] with a blue, indeterminate progress bar on a black background and a "Starting Windows" caption above it. [[Windows 7 build 6941|Build 6941]] is the first known to include the final animation featuring four colored light orbs rotating and forming the Windows flag.

The underlying framework for drawing the boot screen was heavily changed during [[Windows 8]] to support a wider range of display resolutions and a 32-bit color palette through the a new implementation called the Boot Graphics Library (BGFX for short), making use of the [[w:VESA BIOS Extensions|VESA BIOS Extensions]] version 2.0 specification; a large advancement away from the less-sufficient 640×480 display resolution and 4-bit color palette used in the legacy <code>BOOTVID</code> implementation first introduced in [[Windows 2000]] (and later expanded upon in [[Windows XP]]).

The BGFX implementation allows the Windows kernel to display the boot animation at a wider range of resolutions, complemented by a finer level of user control over certain boot screen elements through the use of Boot Configuration Data (BCD) elements containing optimizations for [[Windows Phone 8]]/[[Windows 10 Mobile]] and embedded releases of Microsoft Windows. By default, the Windows logo is used by default for most releases, although certain versions of Windows utilize custom graphics or wordmarks, such as preview builds for [[Windows 8]] and [[Windows 8.1]], internal distributions of Windows such as CoreSystem-based releases or [[Azure Stack HCI]]; in certain cases (such as the Server Core editions included as part of [[Windows Server 2012]]), no boot logo is present.

On systems that support the BGRT specification, the [[w:Original equipment manufacturer|OEM]]-supplied logo presented by the firmware can stay on-screen, even during the Windows boot process and during [[Windows Setup|setup]] (the latter of which is handled by the Windows logon application), replacing the default logo; for legacy BIOS systems, the BGFX library falls back to 16:9 aspect ratio variants of the logo bitmap and ''Segoe Boot'' font face (intended for resolutions of 1366×768px), with resources designated under the <code>N</code> moniker. The resources for the boot screen are stored in BGFX library <code>bootres.dll</code>, both in the form of a bitmap stored inside a WIM file containing six variations of the boot logo for varying screen resolutions, which in turn is stored as a resource in the DLL file, and in multilingual user interface binaries (MUIs) for strings in the boot and [[Blue screen of death|system crash]] screens. Each frame of the spinner animation used in Windows 8 and later are stored as PUA characters within the ''Segoe Boot'' font face, used as part of the boot process.

The boot screen remained largely unchanged throughout the entire [[Windows 10]] series, retaining the cyan Windows logo first introduced in Windows 8. The boot screen was later changed during the development of the [[Windows 11 (original release)|original Windows 11 release]] to include the new operating system logo, followed by a spinner animation originally intended for [[Windows 10X]] being repurposed for subsequent releases of [[Windows 11]] since the [[Windows 11 2022 Update|2022 Update]]. 

<gallery>
File:Windows7-6.1.6469-GUIBoot.png|[[Windows 7 build 6469]]
File:Windows7-6.1.6608-Boot.png|[[Windows 7 build 6519]]
File:Windows7-6.1.6730-Boot.png|[[Windows 7 build 6730]]
File:Windows7-6.1.6780-Boot.png|[[Windows 7 build 6780]]
File:Win7Boot.png|[[Windows 7 build 7600.16385|Windows 7 RTM]]
File:WindowsServer2012-6.2.7965-Boot.png|[[Windows Server 2012 build 7965]]
File:7985boot.png|[[Windows 8 build 7985 (fbl_core1_kernel_cptx.110419-1745)]]
File:8102boot.png|[[Windows 8 build 8102]]
File:Win8boot.png|[[Windows 8 build 9200 (win8_rtm)|Windows 8 RTM]] through [[Windows 10]]
WindowsCoreSystem-10.0.10586.0-BootScreen.png|Boot screen used for internal OneCore-based editions since [[Windows 10 (original release)]]
19587 10XBoot.png|[[Windows 10X]]{{efn|The new spinner animation can also be enabled on late builds of Windows 10 and early Windows 11 builds starting from [[Windows 10 build 19587.1000|build 19587]].}} 
File:Win11-boot-10x-anim.png|[[Windows 11 2022 Update]]
</gallery>

==macOS==
[[Mac OS X Server 1.x]] shows the boot stages of the Mach kernel inside of a window.

[[Mac OS X Developer Preview 1]] through [[Mac OS X Puma|10.1]] show the Happy Mac icon with the NeXTSTEP wait cursor at the top left.

[[Mac OS X Jaguar|Mac OS X 10.2]] through [[OS X Mavericks|OS X 10.9]] show the Apple logo with spinning lines on a white background.

Versions since [[OS X Yosemite|10.10]] show the Apple logo with a progress bar on either a dark or a light background.

<gallery>
File:Macosxserverboot.png|[[Mac OS X Server 1.x]]
File:MacOS-10.0-Boot.png|[[Mac OS X Developer Preview 1|Mac OS X DP1]] - [[Mac OS X Puma|10.1]]
File:MacOS-10.2-Boot.png|[[Mac OS X Jaguar|Mac OS X 10.2]] - [[OS X Mavericks|10.9]]
File:MacOS-10.12-Boot.png|[[OS X Yosemite|OS X 10.10]] and later
File:MacOS 11 boot screen.png|Ditto.
</gallery>

== Notes ==
{{notelist}}