hw/i386.reference/s13_02.htm

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   4 <TITLE>80386 Programmer's Reference Manual -- Section 13.2</TITLE>
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   7 <B>up:</B> <A HREF="c13.htm">
   8 Chapter 13 -- Executing 80286 Protected-Mode Code</A><BR>
   9 <B>prev:</B> <A HREF="s13_01.htm">13.1  80286 Code Executes as a Subset of the 80386</A><BR>
  10 <B>next:</B> <A HREF="s13_03.htm">13.3  Differences From 80286</A>
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  14 <H1>13.2  Two ways to Execute 80286 Tasks</H1>
  15 When porting 80286 programs to the 80386, there are two cases to consider:
  16 <OL>
  17 <LI> Porting an entire 80286 system to the 80386, complete with 80286
  18 operating system, loader, and system builder.
  19 <P>
  20 In this case, all tasks will have 80286 TSSs. The 80386 is being used
  21 as a faster 286.
  22 <P>
  23 <LI> Porting selected 80286 applications to run in an 80386 environment
  24 with an 80386 operating system, loader, and system builder.
  25 <P>
  26 In this case, the TSSs used to represent 80286 tasks should be
  27 changed to 80386 TSSs. It is theoretically possible to mix 80286 and
  28 80386 TSSs, but the benefits are slight and the problems are great. It
  29 is recommended that all tasks in a 80386 software system have 80386
  30 TSSs. It is not necessary to change the 80286 object modules
  31 themselves; TSSs are usually constructed by the operating system, by
  32 the loader , or by the system builder . Refer to
  33 <A HREF="c16.htm">Chapter 16</A>
  34    for further
  35 discussion of the interface between 16-bit and 32-bit code.
  36 </OL>
  37 <P>
  38 <HR>
  39 <P>
  40 <B>up:</B> <A HREF="c13.htm">
  41 Chapter 13 -- Executing 80286 Protected-Mode Code</A><BR>
  42 <B>prev:</B> <A HREF="s13_01.htm">13.1  80286 Code Executes as a Subset of the 80386</A><BR>
  43 <B>next:</B> <A HREF="s13_03.htm">13.3  Differences From 80286</A>
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