code.delx.au - gnu-emacs/blob - src/m/intel386.h

   1 /* Machine description file for intel 386.
   2    Copyright (C) 1987 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 1, or (at your option)
   9 any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20
  21 /* The following line tells the configuration script what sort of
  22    operating system this machine is likely to run.
  23    USUAL-OPSYS="note"
  24
  25 NOTE-START
  26 Intel 386 (-machine=intel386 or -machine=is386.h)
  27
  28   The possibilities for -opsystem are: bsd4-2, usg5-2-2, usg5-3,
  29   isc2-2, 386-ix, esix, or xenix.
  30
  31   18.58 should support a wide variety of operating systems.
  32   Use isc2-2 for Interactive 386/ix version 2.2.
  33   Use 386ix for prior versions.
  34   Use esix for Esix.  It isn't clear what to do on an SCO system.
  35
  36   -machine=is386 is used for an Integrated Solutions 386 machine.
  37   It may also be correct for Microport systems.
  38
  39 Cubix QBx/386 (-machine=intel386 -opsystem=usg5-3)
  40
  41   Changes merged in 19.1.  Systems before 2/A/0 may fail to compile etags.c
  42   due to a compiler bug.
  43
  44 Prime EXL (-machine=intel386 -opsystem=usg5-3)
  45
  46   Minor changes merged in 19.1.
  47 NOTE-END */
  48
  49 /* The following three symbols give information on
  50  the size of various data types.  */
  51
  52 #define SHORTBITS 16            /* Number of bits in a short */
  53
  54 #define INTBITS 32              /* Number of bits in an int */
  55
  56 #define LONGBITS 32             /* Number of bits in a long */
  57
  58 /* i386 is not big-endian: lowest numbered byte is least significant. */
  59
  60 /* #undef BIG_ENDIAN */
  61
  62 /* Define NO_ARG_ARRAY if you cannot take the address of the first of a
  63  * group of arguments and treat it as an array of the arguments.  */
  64
  65 /* #define NO_ARG_ARRAY */
  66
  67 /* Define WORD_MACHINE if addresses and such have
  68  * to be corrected before they can be used as byte counts.  */
  69
  70 /* #define WORD_MACHINE */
  71
  72 /* Define how to take a char and sign-extend into an int.
  73    On machines where char is signed, this is a no-op.  */
  74
  75 #define SIGN_EXTEND_CHAR(c) (c)
  76
  77 /* Now define a symbol for the cpu type, if your compiler
  78    does not define it automatically:
  79    Ones defined so far include vax, m68000, ns16000, pyramid,
  80    orion, tahoe, APOLLO and many others */
  81
  82 #define INTEL386
  83
  84 /* Use type int rather than a union, to represent Lisp_Object */
  85
  86 #define NO_UNION_TYPE
  87
  88 /* crt0.c, if it is used, should use the i386-bsd style of entry.
  89    with no extra dummy args.  On USG and XENIX,
  90    NO_REMAP says this isn't used. */
  91
  92 #define CRT0_DUMMIES bogus_fp,
  93
  94 /* crt0.c should define a symbol `start' and do .globl with a dot.  */
  95
  96 #define DOT_GLOBAL_START
  97
  98 #ifdef XENIX
  99 /* Data type of load average, as read out of kmem.  */
 100 #define LOAD_AVE_TYPE short
 101
 102 /* Convert that into an integer that is 100 for a load average of 1.0  */
 103 #define LOAD_AVE_CVT(x) (((double) (x)) * 100.0 / FSCALE)
 104
 105 #define FSCALE 256.0         /* determined by experimentation...  */
 106 #endif
 107
 108 #ifdef USG5_4 /* Older USG systems do not support the load average.  */
 109 /* Data type of load average, as read out of kmem.  */
 110
 111 #define LOAD_AVE_TYPE long
 112
 113 /* Convert that into an integer that is 100 for a load average of 1.0  */
 114 /* This is totally uncalibrated. */
 115
 116 #define LOAD_AVE_CVT(x) ((int) (((double) (x)) * 100.0 / FSCALE))
 117 #define FSCALE 256.0
 118 #endif
 119
 120 /* Define CANNOT_DUMP on machines where unexec does not work.
 121    Then the function dump-emacs will not be defined
 122    and temacs will do (load "loadup") automatically unless told otherwise.  */
 123
 124 /* #define CANNOT_DUMP */
 125
 126 /* Define VIRT_ADDR_VARIES if the virtual addresses of
 127    pure and impure space as loaded can vary, and even their
 128    relative order cannot be relied on.
 129
 130    Otherwise Emacs assumes that text space precedes data space,
 131    numerically.  */
 132
 133 /* #define VIRT_ADDR_VARIES */
 134
 135 #ifdef XENIX
 136 #define VALBITS 26
 137 #define GCTYPEBITS 5
 138
 139 /* Define NO_REMAP if memory segmentation makes it not work well
 140    to change the boundary between the text section and data section
 141    when Emacs is dumped.  If you define this, the preloaded Lisp
 142    code will not be sharable; but that's better than failing completely.  */
 143
 144 #define NO_REMAP
 145
 146 #define STACK_DIRECTION -1
 147
 148 /* Since cannot purify, use standard Xenix 386 startup code. */
 149
 150 #define START_FILES     /lib/386/Sseg.o pre-crt0.o /lib/386/Scrt0.o
 151
 152 /* These really use terminfo.  */
 153
 154 #define LIBS_TERMCAP /lib/386/Slibcurses.a  \
 155    /lib/386/Slibtinfo.a /lib/386/Slibx.a
 156
 157 /* Standard libraries for this machine.  Since `-l' doesn't work in `ld'.  */
 158 /* '__fltused' is unresolved w/o Slibcfp.a */
 159 #define LIB_STANDARD /lib/386/Slibcfp.a /lib/386/Slibc.a
 160 #else /* not XENIX */
 161
 162 #ifdef USG
 163 #ifndef LIB_STANDARD
 164 #define LIB_STANDARD -lPW -lc
 165 #endif
 166 #define HAVE_ALLOCA
 167 #define NO_REMAP
 168 #define TEXT_START 0
 169 #endif /* USG */
 170 #endif /* not XENIX */
 171
 172 #ifdef BSD
 173 #define HAVE_ALLOCA
 174 #endif /* BSD */
 175
 176 /* If compiling with GCC, let GCC implement alloca.  */
 177 #if defined(__GNUC__) && !defined(alloca)
 178 #define alloca(n) __builtin_alloca(n)
 179 #define HAVE_ALLOCA
 180 #endif
 181
 182 #ifdef USG
 183 #ifdef __STDC__
 184 #ifndef DONT_DEFINE_SIGNAL
 185 /* Cast the function argument to avoid warnings.  */
 186 #define signal(sig, func) (signal (sig, (void (*) (int)) (func)))
 187 #endif
 188 #endif
 189 #endif
 190
 191 #ifdef USG5_4
 192 #define DATA_SEG_BITS 0x08000000
 193 #endif