cvs commit: src/sys/dev/ata ata-disk.c

[Warner Losh]

imp         2006-08-09 18:23:47 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/ata          ata-disk.c 
  Log:
  Most platforms map the actual drive geometry to the firmware's notion
  of geometry.  However, some platforms have a more complicated mapping
  of the firmware values to the actual values.  pc98 is the only
  platform that currently does this.  This mapping is necessary for
  large disks connected to pc98 boxes, as the firmware labels require do
  special hacks to the actual geometry for interoperability.  We cannot
  do this all in the geom layer because of initialization issues (geom
  looks for an already initialized pc98 label, but we need the geometry
  information prior to initialization, classic chicken and egg problem).
  We pass the disk and the device_t to this function because the
  geometry mapping depends on what kind of controller is used.
  
  This hook allows platforms that want to override things to do so, and
  has 0 overhead on all other platforms.  These patches have been in use
  locally for a long time, and received good feedback from the pc98
  community and sos@ at various times during their development.
  
  MFC After: 1 week
  
  Revision  Changes    Path
  1.198     +9 -0      src/sys/dev/ata/ata-disk.c