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, 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.  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 /* Now define a symbol for the cpu type, if your compiler
  73    does not define it automatically:
  74    Ones defined so far include vax, m68000, ns16000, pyramid,
  75    orion, tahoe, APOLLO and many others */
  76
  77 #define INTEL386
  78
  79 /* Use type int rather than a union, to represent Lisp_Object */
  80
  81 #define NO_UNION_TYPE
  82
  83 /* crt0.c, if it is used, should use the i386-bsd style of entry.
  84    with no extra dummy args.  On USG and XENIX,
  85    NO_REMAP says this isn't used. */
  86
  87 #define CRT0_DUMMIES bogus_fp,
  88
  89 /* crt0.c should define a symbol `start' and do .globl with a dot.  */
  90
  91 #define DOT_GLOBAL_START
  92
  93 #ifdef XENIX
  94 /* Data type of load average, as read out of kmem.  */
  95 #define LOAD_AVE_TYPE short
  96
  97 /* Convert that into an integer that is 100 for a load average of 1.0  */
  98 #define LOAD_AVE_CVT(x) (((double) (x)) * 100.0 / FSCALE)
  99
 100 #define FSCALE 256.0         /* determined by experimentation...  */
 101 #endif
 102
 103 #ifdef USG5_4 /* Older USG systems do not support the load average.  */
 104 /* Data type of load average, as read out of kmem.  */
 105
 106 #define LOAD_AVE_TYPE long
 107
 108 /* Convert that into an integer that is 100 for a load average of 1.0  */
 109 /* This is totally uncalibrated. */
 110
 111 #define LOAD_AVE_CVT(x) ((int) (((double) (x)) * 100.0 / FSCALE))
 112 #define FSCALE 256.0
 113 #endif
 114
 115 /* Define CANNOT_DUMP on machines where unexec does not work.
 116    Then the function dump-emacs will not be defined
 117    and temacs will do (load "loadup") automatically unless told otherwise.  */
 118
 119 /* #define CANNOT_DUMP */
 120
 121 /* Define VIRT_ADDR_VARIES if the virtual addresses of
 122    pure and impure space as loaded can vary, and even their
 123    relative order cannot be relied on.
 124
 125    Otherwise Emacs assumes that text space precedes data space,
 126    numerically.  */
 127
 128 /* #define VIRT_ADDR_VARIES */
 129
 130 #ifdef XENIX
 131 #define VALBITS 26
 132 #define GCTYPEBITS 5
 133
 134 /* Define NO_REMAP if memory segmentation makes it not work well
 135    to change the boundary between the text section and data section
 136    when Emacs is dumped.  If you define this, the preloaded Lisp
 137    code will not be sharable; but that's better than failing completely.  */
 138
 139 #define NO_REMAP
 140
 141 #define STACK_DIRECTION -1
 142
 143 /* Since cannot purify, use standard Xenix 386 startup code. */
 144
 145 #define START_FILES     /lib/386/Sseg.o pre-crt0.o /lib/386/Scrt0.o
 146
 147 /* These really use terminfo.  */
 148
 149 #define LIBS_TERMCAP /lib/386/Slibcurses.a  \
 150    /lib/386/Slibtinfo.a /lib/386/Slibx.a
 151
 152 /* Standard libraries for this machine.  Since `-l' doesn't work in `ld'.  */
 153 /* '__fltused' is unresolved w/o Slibcfp.a */
 154 #define LIB_STANDARD /lib/386/Slibcfp.a /lib/386/Slibc.a
 155 #else /* not XENIX */
 156
 157 /* this brings in alloca() if we're using cc */
 158 #ifdef USG
 159 #ifndef LIB_STANDARD
 160 #ifdef USG5_4
 161 #define LIB_STANDARD -lc
 162 #else /* not USG5_4 */
 163 #define LIB_STANDARD -lPW -lc
 164 #endif /* not USG5_4 */
 165 #endif /* LIB_STANDARD */
 166
 167 #define HAVE_ALLOCA
 168 #define NO_REMAP
 169 #define TEXT_START 0
 170 #endif /* not USG */
 171 #endif /* not XENIX */
 172
 173 #ifdef BSD
 174 #define HAVE_ALLOCA
 175 #endif /* BSD */
 176
 177 /* If compiling with GCC, let GCC implement alloca.  */
 178 #if defined(__GNUC__) && !defined(alloca)
 179 #define alloca(n) __builtin_alloca(n)
 180 #define HAVE_ALLOCA
 181 #endif
 182
 183 #ifdef USG5_4
 184 #define DATA_SEG_BITS 0x08000000
 185 #endif