From: muta...@gmail.com   
      
   On Sunday, July 4, 2021 at 4:23:09 PM UTC+10, Rod Pemberton wrote:   
      
   > a) his OS app -> libc -> host OS functions -> trap & replace   
      
   > Option a) is what Paul is struggling with.   
      
   I'm not 100% sure I understand your summary, but   
   the apps I am mainly interested in (such as gccwin),   
   are Win32 programs that are dependent on nothing   
   more than msvcrt.dll. ie not even kernel32.dll.   
      
   So I wish to run gccwin under PDOS-generic   
   (essentially the same as PDOS/386 but with the   
   BIOS decoupled and encapsulated in PDPCLIB,   
   and FAT encapsulated in PDPCLIB).   
      
   PDOS-generic will load gccwin etc, and when filling   
   in all the printf etc function calls (supposedly pointing   
   to msvcrt.dll) with some sort of callback that doesn't   
   necessarily even involve any real file called msvcrt.dll.   
      
   PDOS-generic in turn will not do any actual INT calls   
   itself, but, very similar to the apps, will simply do   
   callbacks to the BIOS layer.   
      
   The BIOS layer may or may not be a simple Windows   
   program written using Borland's C compiler running   
   under Windows 10 or anything at all really.   
      
   The BIOS layer may or may not INSTEAD be called   
   BOOTX32.EFI or whatever 32-bit UEFI is.   
      
   The BIOS layer may or may not INSTEAD be called   
   BOOTX64.EFI and switching from 32 to 16 to 64   
   to 16 to 32.   
      
   If the BIOS layer is a simple Windows program running   
   under some PDOS-generic like OS, the layers can go   
   up and up forever until you find someone who does an   
   actual INT instruction or manipulates the hardware.   
      
   BFN. Paul.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)