cvs commit: src/sys/conf ldscript.ia64

[Marcel Moolenaar]

marcel      2003/09/05 22:15:36 PDT

  FreeBSD src repository

  Modified files:
    sys/conf             ldscript.ia64 
  Log:
  Load the kernel at a 64M instead of 5M. The advantage of this is that
  we can switch to 64M-sized identity mappings and not having to map the
  first 64M. This is especially important because the first 1M contains
  the VGA frame buffer and is otherwise a legacy memory range. Best to
  make as little assumptions about it as possible. Switching to 64M-sized
  mappings is important to avoid creating overlapping translations, which
  have the side-effect of triggering machine checks. This is currently
  what's preventing us to boot on an Intel Tiger 4.
  
  Note that since we currently use 256M-sized identity mappings, we
  would reduce the size of the mappings and consequently increase the
  TLB pressure. The performance implications of this are minimal if
  measurable at all because identify mappings are not our primary
  means for memory management.
  
  Also note that there's no guarantee that physical memory exists at
  64M. Then again, we didn't had the guarantee when we were loading at
  5M. We'll deal with this when it's a problem.
  
  Discussed with: arun@
  
  Revision  Changes    Path
  1.10      +1 -1      src/sys/conf/ldscript.ia64