Editing VESA BIOS Extensions (section)

{{Short description|Video board software standard}}
{{Redirect|VBE}}
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'''VESA BIOS Extensions''' ('''VBE''') is a [[VESA]] standard, currently at version 3, that defines the interface that can be used by software to access compliant video boards at high resolutions and bit depths. This is opposed to the "traditional" [[INT 10H|INT 10h]] [[BIOS]] calls, which are limited to resolutions of 640×480 [[pixel]]s with 16 colour (4-bit) depth or less. VBE is made available through the [[Video BIOS|video card's BIOS]], which installs some [[interrupt]] vectors that [[Pointer (computer programming)|point to]] itself during [[booting|boot up]].

Most newer cards implement the more capable VBE 3.0 standard. Older versions of VBE provide only a [[real mode]] interface, which cannot be used without a significant performance penalty from within [[protected mode]] operating systems. Consequently, the VBE standard has almost never been used for writing a video card's drivers; each vendor has thus had to invent a [[proprietary protocol]] for communicating with its own video card. Despite this, it is common that a driver [[thunk (compatibility mapping)|thunk]] out to the real mode interrupt in order to initialize screen modes and gain direct access to a card's [[framebuffer|linear frame buffer]], because these tasks would otherwise require handling many hundreds of proprietary variations that exist from card to card.

In [[Extensible Firmware Interface|EFI]] 1.x systems, the INT 10H and the VESA BIOS Extensions (VBE) are replaced by the EFI UGA protocol. In widely used [[UEFI]] 2.x systems, the INT 10H and the VBE are replaced by the [[UEFI GOP]].<ref>{{Cite web|title=What is efifb? — The Linux Kernel documentation|url=https://www.kernel.org/doc/html/latest/fb/efifb.html|access-date=2020-11-24|website=kernel.org}}</ref><ref>{{Cite web|title=What is vesafb? — The Linux Kernel documentation|url=https://www.kernel.org/doc/html/latest/fb/vesafb.html|access-date=2020-11-24|website=kernel.org}}</ref>