From: muta...@gmail.com   
      
   On Monday, March 20, 2023 at 8:54:21 PM UTC+8, wolfgang kern wrote:   
      
   > > I assume the syntax would be:    
   > >    
   > > mov eax, after    
   > > mov [esp + 0], eax    
   > > mov eax, sub    
   > > jmp *eax    
   > > after:    
   > >    
   > > sub:    
   > > ...    
   > > mov eax, [esp + 0]    
   > > jmp *eax   
   > this may not work as you expect.    
      
   Why not?   
      
   > and what's wrong with call/ret in long mode    
   >    
   > FF D0 .... C3    
   > 48 FF D0 .... C3    
      
   I want my 32-bit code to work on both an 80386 and on   
   an x64 in long mode.   
      
   > if you like to run 32 bit code within 64 bit environment then just    
   > switch back and forth between this two modes.    
   > Oh, you don't have a BIOS/UEFI function for such ? write your own.    
      
   I don't want to write my own. I want to follow the EFI   
   spec and have carefully-generated assembler that can   
   tolerate running on both 32 and 64-bit environments.   
      
   I'm not sure there is actually a way to write my own   
   even outside of the EFI spec. Don't I need access to   
   the GDT or whatever which can't be manipulated until   
   I exit boot services?   
      
   BFN. Paul.   
      
   --- SoupGate-Win32 v1.05   
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