Hi, Sector size of disks starting with very old diskettes are 512 byte until now. Exceptions have arisen nearly recently (2010) when some HDD manufacturers (I know about WD) introduced hard drives with 4096 byte physical sectors. But the change has made only on internals of HD drive, logically no changes required to programs to work, although working with ordinary "small" 512 sectors aligned on these "big" sector boundaries makes the disk work much faster. HDD manufacturers provide special utilities for aligning the partition start sectors, by moving these partitions to nearest boundary
More details are here: http://en.wikipedia.org/wiki/Advanced_Format The summary is that practically, treating size sectors as 512 bytes will work yet for very long time, and for near future it would be enough to align partitions. That said, in long run, naturally, it would be better to encounter real sectors' size. Regards, M.A. On Thu, Aug 23, 2012 at 9:48 PM, Timo Kreuzer <timo.kreu...@web.de> wrote: > Btw, we are using a lot of hardcoded 512 values here for sector size even > though there is a field in the Volume structure for that. > Is that correct? > > > Am 23.08.2012 14:02, schrieb tkreu...@svn.reactos.org: > >> Author: tkreuzer >> Date: Thu Aug 23 12:02:30 2012 >> New Revision: 57141 >> >> URL: http://svn.reactos.org/svn/reactos?rev=57141&view=rev >> Log: >> [FREELDR] >> Improve readability of sector calculation >> >> Modified: >> trunk/reactos/boot/freeldr/freeldr/fs/fat.c >> >> Modified: trunk/reactos/boot/freeldr/freeldr/fs/fat.c >> URL: >> http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/fs/fat.c?rev=57141&r1=57140&r2=57141&view=diff >> >> ============================================================================== >> --- trunk/reactos/boot/freeldr/freeldr/fs/fat.c [iso-8859-1] (original) >> +++ trunk/reactos/boot/freeldr/freeldr/fs/fat.c [iso-8859-1] Thu Aug 23 >> 12:02:30 2012 >> @@ -1338,8 +1338,7 @@ >> // >> // Seek to right position >> // >> - Position.HighPart = SectorNumber >> 23; >> - Position.LowPart = SectorNumber << 9; >> + Position.QuadPart = (ULONGLONG)SectorNumber * 512; >> ret = ArcSeek(Volume->DeviceId, &Position, SeekAbsolute); >> if (ret != ESUCCESS) >> { _______________________________________________ Ros-dev mailing list Ros-dev@reactos.org http://www.reactos.org/mailman/listinfo/ros-dev
