Thunderbird/5.0   
   s2.utilities,comp.os.os2.beta   
   UTC)   
   comp.os.os2.misc:3457 comp.os.os2.utilities:219 comp.os.os2.beta:181   
   From: Jonathan de Boyne Pollard    
      
   One cannot boot IBM OS/2 directly from EFI firmware.  IBM OS/2 is only    
   bootable in the old PC/AT way.  Maybe the osFree people working on their    
   FREELDR will work on a version that can run on EFI systems.  (If you're    
   reading this: You won't have to worry about switching into protected    
   mode, using mini-FSDs, enabling A20 gates, or any of that chaff.  The    
   firmware will do all that for you.)   
      
   It's possible to make an old PC98 machine into a Poor Man's EFI machine,    
   using DUET ("Developers' UEFI Emulation Tool").  This is, basically, a    
   program image that is booted as if it were an old-style PC/AT operating    
   system, that loads up a reference implementation of EFI firmware and    
   displays the EFI Boot Manager.  One can then run EFI "pre-boot"    
   applications (from Microsoft's old DISKPART.EFI to the stuff that one    
   can now get for Intel Macintoshes) and bootstrap EFI operating system    
   boot loader programs on top of it, just as one would on a true EFI    
   system.  There is even the good old built-in UEFI Shell, complete with    
   text editor, file manipulation tools, and whatnot.  The downside is    
   that, as supplied, DUET's own bootstrap mechanism leaves a huge amount    
   to be desired.  If you've ever used it, you'll know that you have to    
   pick the right version from about eight different program image files,    
   otherwise it will mysteriously hang or reboot.  You also have to,    
   somewhat madly, use different names for the program image file according    
   to whether you are using FAT12, FAT16, or FAT32.  It's quite nutty.   
      
   Not any more.   
      
   To complement the MBR with EFI partition table support, that I mentioned    
   a couple of weeks ago, I've written a TAU boot loader for DUET.  This    
   uses exactly the same bootstrap process as my boot manager, except that    
   in the final stage instead of loading my Boot Manager it loads up DUET    
   instead.  It allows you to use any filename you like for the program    
   image, and it doesn't matter if one doesn't use the image that exactly    
   matches the FAT width of the containing disc volume.  (You've still got    
   to pick the right image for x86-32 versus x86-64, though.  I cannot do    
   anything about that.)   
      
   I now have here, thanks to both, a system with PC/AT firmware that has    
   an EFI partition table, an EFI System Partition, and DUET.  It    
   bootstraps directly to the EFI System Partition (thanks to the MBR with    
   EFI partition table support) and thence into DUET (thanks to the TAU    
   boot loader for DUET).  So it goes from POST straight to the EFI Boot    
   Manager, with nothing more than a few copyright messages along the way.  (-:   
      
   I've put up the step-by-step process of how I did it on a page that    
   you'll find hyperlinked-to from the TAU System Utilities page on my own    
   WWW server.  I've subtly named the hyperlink "Instructions for    
   installing TAU Boot Manager or UEFI DUET onto a system volume".  All of    
   the tools for following the procedure are in the latest TAU System    
   Utilities archive.   
      
   Once one has booted a system into x86-64 DUET one, according to    
   Microsoft, can install Windows NT 6.1 ("Windows 7") using its x86-64 EFI    
   installer, rather than its PC98 installer.  The EFI installer will    
   install the EFI versions of Microsoft's Boot Manager and Boot    
   Configuration Data, into an EFI System Partition; something that is not    
   possible to do with the PC98 installer.  (Beware:  Windows 7 requires a    
   bona fide EFI System Partition for this trick, not a Poor Man's    
   equivalent such as a System Reserved Partition.)  Thence one can install    
   Linux with ELILO and other EFI-bootable operating systems, and have them    
   all on the menu of DUET's EFI Boot Manager, which becomes the primary    
   boot manager for the system.  Combine all that with an EFI partition    
   table, and you get (a) no more headaches caused by the differences    
   between secondary and primary partitions; (b) no "hybrid MBR"    
   partitioning nonsense; (c) no more 2TiB disc limit worries; (d) no more    
   problems from boot managers that work as MBR computer viruses; (e) no    
   more dealings with "MBR disc signatures", "LVM info sectors", or other    
   such nonsense; and (f) the EFI Shell accessible at boot time.  Oh: and    
   you get 36 character Unicode names for your partitions, too. (-:   
      
   Unfortunately, one cannot boot IBM OS/2 or eComStation from the EFI Boot    
   Manager.  They don't have the right kind of operating system boot    
   loader.  So I encourage you to prod the osFree and the eComStation    
   people to make EFI versions of OS2LDR and FREELDR.   
      
   --- Internet Rex 2.31   
    * Origin: virginmedia.com (1:261/20.999)