BIOS boot partition: Difference between revisions

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Overview: find the alignment spec text
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}}</ref> (which, when written to a GPT in the required little endian fields, forms the ASCII string "<code>Hah!IdontNeedEFI</code>").<!-- See talk page for some notes on endianness confusion. --> In the context of GPT on a BIOS-based computer, a BIOS boot partition is similar in some respects to the [[EFI system partition]], which is used by systems based on [[Extensible Firmware Interface|EFI]]. The EFI System partition holds a filesystem and files used by the UEFI, while the BIOS boot partition is used in BIOS-based systems and accessed without a filesystem by holding raw binary code.
 
The size requirements for a BIOS boot partition are quite low so it can be as small as about 30&nbsp;KiB; however, as future boot loaders might require more space, 1&nbsp;MiB might be a reasonable BIOS boot partition size. Due to the [[1 MB partition alignment|1&nbsp;MiB partition alignment]] policies used by most modern disk partitioning tools to provide optimum performance with [[Advanced Format]] disks, [[Solid-state drive|SSD devices]] and certain [[RAID]] configurations, some room is left allowing the placement of a BIOS boot partition between the GPT and the first partition aligned that way (34&ndash;2048 for 512-byte sectors; 6&ndash;255 for 4096-byte sectors). If created by utilizing that free space, the BIOS boot partition would be out of the GPT alignment specification,<ref>See buthttps://uefi.org/specs/UEFI/2.10/05_GUID_Partition_Table_Format.html, thattext isstarting notwith very"GPT important{{citationpartitions needed|date=Juneshould 2017|reason=Whobe saysaligned itto isthe unimportant?larger Isof".</ref> thisbut justthat opinionis ornot isvery itimportant declaredsince: in(a) the partitioningalignment standardrule /is bootloader's"should" documentation?and Evennot if"must" it(b) isthe *written*rule tois rarely,based iton isa *read*performance every bootconsideration, andwhich anythingfor thata clobbersvery itsmall willpartition preventused theonly at system from being able to boot.}} sincebears itno is written to veryreal infrequentlyconsequence.
 
== Creation ==