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 2, 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, linux, sco3.2v4, and 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.
  35   Use linux for Linux.
  36   It isn't clear what to do on an SCO system.
  37
  38   -machine=is386 is used for an Integrated Solutions 386 machine.
  39   It may also be correct for Microport systems.
  40
  41 Cubix QBx/386 (-machine=intel386 -opsystem=usg5-3)
  42
  43   Changes merged in 19.1.  Systems before 2/A/0 may fail to compile etags.c
  44   due to a compiler bug.
  45
  46 Prime EXL (-machine=intel386 -opsystem=usg5-3)
  47
  48   Minor changes merged in 19.1.
  49 NOTE-END */
  50
  51 /* The following three symbols give information on
  52  the size of various data types.  */
  53
  54
  55 /* Linux defines these in <values.h>, but they can't be used in #if's */
  56 #undef SHORTBITS
  57 #undef INTBITS
  58 #undef LONGBITS
  59
  60 #define SHORTBITS 16            /* Number of bits in a short */
  61
  62 #define INTBITS 32              /* Number of bits in an int */
  63
  64 #define LONGBITS 32             /* Number of bits in a long */
  65
  66 /* i386 is not big-endian: lowest numbered byte is least significant. */
  67
  68 /* #undef BIG_ENDIAN */
  69
  70 /* Define NO_ARG_ARRAY if you cannot take the address of the first of a
  71  * group of arguments and treat it as an array of the arguments.  */
  72
  73 /* #define NO_ARG_ARRAY */
  74
  75 /* Define WORD_MACHINE if addresses and such have
  76  * to be corrected before they can be used as byte counts.  */
  77
  78 /* #define WORD_MACHINE */
  79
  80 /* Now define a symbol for the cpu type, if your compiler
  81    does not define it automatically:
  82    Ones defined so far include vax, m68000, ns16000, pyramid,
  83    orion, tahoe, APOLLO and many others */
  84
  85 #define INTEL386
  86
  87 /* Use type int rather than a union, to represent Lisp_Object */
  88
  89 #define NO_UNION_TYPE
  90
  91 /* crt0.c, if it is used, should use the i386-bsd style of entry.
  92    with no extra dummy args.  On USG and XENIX,
  93    NO_REMAP says this isn't used. */
  94
  95 #define CRT0_DUMMIES bogus_fp,
  96
  97 /* crt0.c should define a symbol `start' and do .globl with a dot.  */
  98
  99 #define DOT_GLOBAL_START
 100
 101 #ifdef XENIX
 102 /* Data type of load average, as read out of kmem.  */
 103 #define LOAD_AVE_TYPE short
 104
 105 /* Convert that into an integer that is 100 for a load average of 1.0  */
 106 #define LOAD_AVE_CVT(x) (((double) (x)) * 100.0 / FSCALE)
 107
 108 #define FSCALE 256.0         /* determined by experimentation...  */
 109 #endif
 110
 111 #ifdef USG5_4 /* Older USG systems do not support the load average.  */
 112 /* Data type of load average, as read out of kmem.  */
 113
 114 #define LOAD_AVE_TYPE long
 115
 116 /* Convert that into an integer that is 100 for a load average of 1.0  */
 117 /* This is totally uncalibrated. */
 118
 119 #define LOAD_AVE_CVT(x) ((int) (((double) (x)) * 100.0 / FSCALE))
 120 #define FSCALE 256.0
 121 #endif
 122
 123 /* Define CANNOT_DUMP on machines where unexec does not work.
 124    Then the function dump-emacs will not be defined
 125    and temacs will do (load "loadup") automatically unless told otherwise.  */
 126
 127 /* #define CANNOT_DUMP */
 128
 129 /* Define VIRT_ADDR_VARIES if the virtual addresses of
 130    pure and impure space as loaded can vary, and even their
 131    relative order cannot be relied on.
 132
 133    Otherwise Emacs assumes that text space precedes data space,
 134    numerically.  */
 135
 136 /* #define VIRT_ADDR_VARIES */
 137
 138 #ifdef XENIX
 139 #define VALBITS 26
 140 #define GCTYPEBITS 5
 141
 142 /* Define NO_REMAP if memory segmentation makes it not work well
 143    to change the boundary between the text section and data section
 144    when Emacs is dumped.  If you define this, the preloaded Lisp
 145    code will not be sharable; but that's better than failing completely.  */
 146
 147 #define NO_REMAP
 148
 149 #define STACK_DIRECTION -1
 150
 151 /* Since cannot purify, use standard Xenix 386 startup code. */
 152
 153 #define START_FILES     /lib/386/Sseg.o pre-crt0.o /lib/386/Scrt0.o
 154
 155 /* These really use terminfo.  */
 156
 157 #define LIBS_TERMCAP /lib/386/Slibcurses.a  \
 158    /lib/386/Slibtinfo.a /lib/386/Slibx.a
 159
 160 /* Standard libraries for this machine.  Since `-l' doesn't work in `ld'.  */
 161 /* '__fltused' is unresolved w/o Slibcfp.a */
 162 #define LIB_STANDARD /lib/386/Slibcfp.a /lib/386/Slibc.a
 163 #else /* not XENIX */
 164
 165 /* this brings in alloca() if we're using cc */
 166 #ifdef USG
 167 #ifndef LIB_STANDARD
 168 #ifdef USG5_4
 169 #define LIB_STANDARD -lc
 170 #else /* not USG5_4 */
 171 #define LIB_STANDARD -lPW -lc
 172 #endif /* not USG5_4 */
 173 #endif /* LIB_STANDARD */
 174
 175 #define HAVE_ALLOCA
 176 #define NO_REMAP
 177 #define TEXT_START 0
 178 #endif /* not USG */
 179 #endif /* not XENIX */
 180
 181 #ifdef BSD
 182 #define HAVE_ALLOCA
 183 #endif /* BSD */
 184
 185 /* If compiling with GCC, let GCC implement alloca.  */
 186 #if defined(__GNUC__) && !defined(alloca)
 187 #define alloca(n) __builtin_alloca(n)
 188 #define HAVE_ALLOCA
 189 #endif
 190
 191 #ifdef USG5_4
 192 #define DATA_SEG_BITS 0x08000000
 193 #endif