> > >FYI, Windows XP creates MBR in the first sector even on a removable > > >2KB/sec MO disk and it seems to use physical block numbers. > > > > I haven't found an official spec for MBR on non-512byte blocks, but > > so far everyone seems to use the first 512 bytes from LBA 0. > > That is my suspicion - which probably means most of the boot code doesn't > know about the actual sector size!
I wonder if there was other possible scenario.. Anyway, if BIOS (or firmware) uses bytes (or other different units from one for LBA in MBR) for I/O strategy, we have to know sectorsize. > Netbsd's fdisk could be changed to do 8k reads (as I changed installboot). > But that might cause a problem is there are insufficient unused sectors > before the first partition (or next partition for the extended partition > list). fdisk(8) should know hardware sector size anyway. Otherwize it can't calculate LBA in the sector size from partition size in MB or GB. --- Izumi Tsutsui