SATA: Difference between revisions

← Older edit

SATA (view source)

Revision as of 20:23, 9 July 2023

915 bytes added , 11 months ago

no edit summary

[unchecked revision]

VisualWikitext

Anonymous user

osdev>Khaledhammouda

Revision as of 22:52, 20 October 2012 (view source) osdev>Jammmie999 No edit summary ← Older edit		Latest revision as of 20:23, 9 July 2023 (view source) osdev>Khaledhammouda No edit summary
(6 intermediate revisions by 5 users not shown)
Line 1: '''SATA''' Stands for "Serial AT Attachment", and is the current leading standard for harddrives and optical media, having succeeded the [[ATA\|(Parallel) ATA]] interface. Practically all SATA drives can be used using either [[AHCI]] or [[ATA PIO Mode\|ATA]]. Apparently, there are three supposedly definitive, conflicting standards for SATA. It may be best to wait for the industry to shake out a little more completely, before trying to write SATA drivers.▼ If you want to try anyway, then get the ATA7, and ATA8 technical docs from www.t13.org. Then maybe try paying $25 to get the technical specs from www.sata-io.org. Hopefully, the discrepancies between the standards aren't too bad.▼ ==Introduction== SATA~~, short for Serial ATA,~~ is a bus interface for communicating with mass storage devices (such ~~asdisk~~as disk drives, optical drives, etc). ~~SATA~~The ~~provides~~composition ~~higher~~is ~~transfer~~mostly ~~rates~~identical ~~than~~to PATA, ~~and~~where isone ~~backward~~controller ~~compatible~~connects to several devices using SATA cables. IfSATA anwiring OSis ~~does~~also ~~not~~one-on-one ~~recognize~~instead of allowing more than one device to be connected to a single cable. When SATA was introduced, italmost ~~can~~all ~~use~~host ~~drives~~controllers ~~like~~were ~~ordinary~~configured to masquerade as an PATA ~~drives~~controller, ~~with~~needing no ~~issues~~change from the existing disk drivers. The majority of SATA ~~specification~~controllers isalso ~~split~~support ~~into~~[[AHCI]], ~~three~~which ~~distinct~~offers ~~protocol~~connecting ~~'layers'~~more devices than PATA allows, and significant other advantages over the legacy protocol. Computers that are currently shipped often are [[AHCI]] only, and backwards compatibility mode, if present, has to be manually enabled from the BIOS - a change that often comes with the cost of making the installed OSes unbootable. The actual SATA specification is split into three distinct protocol 'layers'. * Physical Layer - Information relating to the physical connectors, etc. Not especially relevant here. * Link Layer * Transport Layer ▲~~Apparently~~At the time of writing, there ~~are~~were three supposedly definitive, conflicting standards for SATA. It may be best to wait for the industry to shake out a little more completely, before trying to write SATA drivers. ▲If you want to try anyway, then get the ATA7, and ATA8 technical docs from [http://www.t13.org www.t13.org]. Then maybe try paying $25 to get the technical specs from www.sata-io.org. Hopefully, the discrepancies between the standards aren't too bad. ==Detection and Initialization== Send a standard IDENTIFY command to the drive (0xEC). The drive should respond with an error in the ERR bit of the Status Register, and a pair of "signature bytes". On the Primary ATA bus, you get the signature bytes by reading IO ports 0x1F4 and 0x1F5, and you should see values of 0x3C and 0xC3. ~~==x86 Examples==~~ ~~==Comments==~~ ==See Also== * [[AHCI]] ===External Links=== Line 26 ⟶ 28: * http://www.ata-atapi.com -- Public Domain C driver sourcecode, including SATA, Busmatering DMA, ATAPI -- not perfect, but good. ~~{{stub}}~~ [[Category:ATA]] [[Category:Disks]] [[Category:Storage]] [[Category:Standards]]