From 0075bbfc5cd1073ba940aac964a7611f06a752d5 Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Sun, 1 Oct 1995 07:19:42 +0000
Subject: [PATCH] Patches to get the microcode to compile properly on Linux ELF
 systems.

---
 v7/src/microcode/cmpauxmd/i386.m4 |  8 ++++++--
 v7/src/microcode/s/linux.h        | 32 ++++++++++++++++++++++++++++++-
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/v7/src/microcode/cmpauxmd/i386.m4 b/v7/src/microcode/cmpauxmd/i386.m4
index 72e04715a..94fd6e8af 100644
--- a/v7/src/microcode/cmpauxmd/i386.m4
+++ b/v7/src/microcode/cmpauxmd/i386.m4
@@ -1,6 +1,6 @@
 ### -*-Midas-*-
 ###
-###	$Id: i386.m4,v 1.36 1995/02/26 03:34:36 cph Exp $
+###	$Id: i386.m4,v 1.37 1995/10/01 07:19:42 cph Exp $
 ###
 ###	Copyright (c) 1992-95 Massachusetts Institute of Technology
 ###
@@ -139,12 +139,16 @@ ifdef(`DOS',
       `define(use_external_code,`')')
 
 ifdef(`OS2',
+      `define(`SUPPRESS_LEADING_UNDERSCORE',1)',
+      `')
+
+ifdef(`SUPPRESS_LEADING_UNDERSCORE',
       `define(external_data_reference,`$1')',
       `define(external_data_reference,`_$1')')
 
 define(EDR,`external_data_reference($1)')
 
-ifdef(`OS2',
+ifdef(`SUPPRESS_LEADING_UNDERSCORE',
       `define(external_code_reference,`$1')',
       `define(external_code_reference,`_$1')')
 
diff --git a/v7/src/microcode/s/linux.h b/v7/src/microcode/s/linux.h
index e70d9fcd3..ba5c8c542 100644
--- a/v7/src/microcode/s/linux.h
+++ b/v7/src/microcode/s/linux.h
@@ -1,7 +1,7 @@
 /* -*-C-*-
    System file for Linux
 
-$Id: linux.h,v 1.2 1995/06/29 23:50:31 cph Exp $
+$Id: linux.h,v 1.3 1995/10/01 07:19:07 cph Exp $
 
 Copyright (c) 1995 Massachusetts Institute of Technology
 
@@ -40,3 +40,33 @@ MIT in each case. */
 #define LIB_DEBUG
 
 #define ALTERNATE_M4 s/ultrix.m4
+
+/* The following change is necessary if ELF binaries are used.
+   Unfortunately, it is insufficient, because the Linux ELF
+   implementation also moves the data segment to 0x08000000, which
+   means that all of the pointer manipulation code must be changed.
+   This is normal for some architectures, e.g. the MIPS and HPPA, but
+   it make the binaries for Linux ELF different for the binaries for
+   all other i386 machines.
+
+   Since I don't currently know any way to adjust the mapping of the
+   data segment, if ELF is in use, I'll just force the switch that
+   causes GCC to generate a.out format instead of ELF.  This is a
+   temporary patch, because one of these days a.out won't be
+   supported, but hopefully by then we'll know how to fix this
+   correctly.  */
+#if 0
+#ifdef __ELF__
+#define M4_SWITCH_SYSTEM -P "define(SUPPRESS_LEADING_UNDERSCORE,1)"
+#else
+#define M4_SWITCH_SYSTEM
+#endif
+#endif
+
+#ifdef __ELF__
+#define C_SWITCH_SYSTEM -b i486-linuxaout
+#define LD_SWITCH_SYSTEM -b i486-linuxaout
+#else
+#define C_SWITCH_SYSTEM
+#define LD_SWITCH_SYSTEM
+#endif
-- 
2.25.1