| 1 | /* This file is a modified version of 'a.out.h'.  It is to be used in all | 
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| 2 | GNU tools modified to support the i80960 (or tools that operate on | 
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| 3 | object files created by such tools). | 
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| 4 |  | 
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| 5 | Copyright 2001 Free Software Foundation, Inc. | 
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| 6 |  | 
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| 7 | This program is free software; you can redistribute it and/or modify | 
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| 8 | it under the terms of the GNU General Public License as published by | 
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| 9 | the Free Software Foundation; either version 2 of the License, or | 
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| 10 | (at your option) any later version. | 
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| 11 |  | 
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| 12 | This program is distributed in the hope that it will be useful, | 
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| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | 
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| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
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| 15 | GNU General Public License for more details. | 
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| 16 |  | 
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| 17 | You should have received a copy of the GNU General Public License | 
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| 18 | along with this program; if not, write to the Free Software | 
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| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */ | 
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| 20 |  | 
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| 21 | /* All i80960 development is done in a CROSS-DEVELOPMENT environment.  I.e., | 
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| 22 | object code is generated on, and executed under the direction of a symbolic | 
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| 23 | debugger running on, a host system.  We do not want to be subject to the | 
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| 24 | vagaries of which host it is or whether it supports COFF or a.out format, | 
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| 25 | or anything else.  We DO want to: | 
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| 26 |  | 
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| 27 | o always generate the same format object files, regardless of host. | 
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| 28 |  | 
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| 29 | o have an 'a.out' header that we can modify for our own purposes | 
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| 30 | (the 80960 is typically an embedded processor and may require | 
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| 31 | enhanced linker support that the normal a.out.h header can't | 
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| 32 | accommodate). | 
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| 33 |  | 
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| 34 | As for byte-ordering, the following rules apply: | 
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| 35 |  | 
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| 36 | o Text and data that is actually downloaded to the target is always | 
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| 37 | in i80960 (little-endian) order. | 
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| 38 |  | 
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| 39 | o All other numbers (in the header, symbols, relocation directives) | 
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| 40 | are in host byte-order:  object files CANNOT be lifted from a | 
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| 41 | little-end host and used on a big-endian (or vice versa) without | 
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| 42 | modification. | 
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| 43 | ==> THIS IS NO LONGER TRUE USING BFD.  WE CAN GENERATE ANY BYTE ORDER | 
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| 44 | FOR THE HEADER, AND READ ANY BYTE ORDER.  PREFERENCE WOULD BE TO | 
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| 45 | USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST.  <== | 
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| 46 |  | 
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| 47 | o The downloader ('comm960') takes care to generate a pseudo-header | 
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| 48 | with correct (i80960) byte-ordering before shipping text and data | 
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| 49 | off to the NINDY monitor in the target systems.  Symbols and | 
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| 50 | relocation info are never sent to the target.  */ | 
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| 51 |  | 
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| 52 | #define BMAGIC  0415 | 
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| 53 | /* We don't accept the following (see N_BADMAG macro). | 
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| 54 | * They're just here so GNU code will compile. | 
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| 55 | */ | 
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| 56 | #define OMAGIC  0407            /* old impure format */ | 
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| 57 | #define NMAGIC  0410            /* read-only text */ | 
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| 58 | #define ZMAGIC  0413            /* demand load format */ | 
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| 59 |  | 
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| 60 | /* FILE HEADER | 
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| 61 | *      All 'lengths' are given as a number of bytes. | 
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| 62 | *      All 'alignments' are for relinkable files only;  an alignment of | 
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| 63 | *              'n' indicates the corresponding segment must begin at an | 
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| 64 | *              address that is a multiple of (2**n). | 
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| 65 | */ | 
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| 66 | struct external_exec { | 
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| 67 | /* Standard stuff */ | 
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| 68 | unsigned char e_info[4];        /* Identifies this as a b.out file */ | 
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| 69 | unsigned char e_text[4];        /* Length of text */ | 
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| 70 | unsigned char e_data[4];        /* Length of data */ | 
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| 71 | unsigned char e_bss[4];         /* Length of uninitialized data area */ | 
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| 72 | unsigned char e_syms[4];        /* Length of symbol table */ | 
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| 73 | unsigned char e_entry[4];       /* Runtime start address */ | 
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| 74 | unsigned char e_trsize[4];      /* Length of text relocation info */ | 
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| 75 | unsigned char e_drsize[4];      /* Length of data relocation info */ | 
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| 76 |  | 
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| 77 | /* Added for i960 */ | 
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| 78 | unsigned char e_tload[4];       /* Text runtime load address */ | 
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| 79 | unsigned char e_dload[4];       /* Data runtime load address */ | 
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| 80 | unsigned char e_talign[1];      /* Alignment of text segment */ | 
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| 81 | unsigned char e_dalign[1];      /* Alignment of data segment */ | 
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| 82 | unsigned char e_balign[1];      /* Alignment of bss segment */ | 
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| 83 | unsigned char e_relaxable[1];   /* Assembled with enough info to allow linker to relax */ | 
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| 84 | }; | 
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| 85 |  | 
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| 86 | #define EXEC_BYTES_SIZE (sizeof (struct external_exec)) | 
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| 87 |  | 
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| 88 | /* These macros use the a_xxx field names, since they operate on the exec | 
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| 89 | structure after it's been byte-swapped and realigned on the host machine. */ | 
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| 90 | #define N_BADMAG(x)     (((x).a_info)!=BMAGIC) | 
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| 91 | #define N_TXTOFF(x)     EXEC_BYTES_SIZE | 
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| 92 | #define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text ) | 
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| 93 | #define N_TROFF(x)      ( N_DATOFF(x) + (x).a_data ) | 
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| 94 | #define N_TRELOFF       N_TROFF | 
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| 95 | #define N_DROFF(x)      ( N_TROFF(x) + (x).a_trsize ) | 
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| 96 | #define N_DRELOFF       N_DROFF | 
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| 97 | #define N_SYMOFF(x)     ( N_DROFF(x) + (x).a_drsize ) | 
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| 98 | #define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms ) | 
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| 99 | #define N_DATADDR(x)    ( (x).a_dload ) | 
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| 100 |  | 
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| 101 | /* Address of text segment in memory after it is loaded.  */ | 
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| 102 | #if !defined (N_TXTADDR) | 
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| 103 | #define N_TXTADDR(x) 0 | 
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| 104 | #endif | 
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| 105 |  | 
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| 106 | /* A single entry in the symbol table | 
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| 107 | */ | 
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| 108 | struct nlist { | 
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| 109 | union { | 
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| 110 | char    *n_name; | 
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| 111 | struct nlist *n_next; | 
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| 112 | long    n_strx;         /* Index into string table      */ | 
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| 113 | } n_un; | 
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| 114 | unsigned char n_type;   /* See below                            */ | 
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| 115 | char    n_other;        /* Used in i80960 support -- see below  */ | 
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| 116 | short   n_desc; | 
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| 117 | unsigned long n_value; | 
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| 118 | }; | 
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| 119 |  | 
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| 120 |  | 
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| 121 | /* Legal values of n_type | 
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| 122 | */ | 
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| 123 | #define N_UNDF  0       /* Undefined symbol     */ | 
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| 124 | #define N_ABS   2       /* Absolute symbol      */ | 
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| 125 | #define N_TEXT  4       /* Text symbol          */ | 
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| 126 | #define N_DATA  6       /* Data symbol          */ | 
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| 127 | #define N_BSS   8       /* BSS symbol           */ | 
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| 128 | #define N_FN    31      /* Filename symbol      */ | 
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| 129 |  | 
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| 130 | #define N_EXT   1       /* External symbol (OR'd in with one of above)  */ | 
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| 131 | #define N_TYPE  036     /* Mask for all the type bits                   */ | 
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| 132 | #define N_STAB  0340    /* Mask for all bits used for SDB entries       */ | 
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| 133 |  | 
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| 134 | /* MEANING OF 'n_other' | 
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| 135 | * | 
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| 136 | * If non-zero, the 'n_other' fields indicates either a leaf procedure or | 
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| 137 | * a system procedure, as follows: | 
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| 138 | * | 
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| 139 | *      1 <= n_other <= 32 : | 
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| 140 | *              The symbol is the entry point to a system procedure. | 
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| 141 | *              'n_value' is the address of the entry, as for any other | 
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| 142 | *              procedure.  The system procedure number (which can be used in | 
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| 143 | *              a 'calls' instruction) is (n_other-1).  These entries come from | 
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| 144 | *              '.sysproc' directives. | 
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| 145 | * | 
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| 146 | *      n_other == N_CALLNAME | 
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| 147 | *              the symbol is the 'call' entry point to a leaf procedure. | 
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| 148 | *              The *next* symbol in the symbol table must be the corresponding | 
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| 149 | *              'bal' entry point to the procedure (see following).  These | 
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| 150 | *              entries come from '.leafproc' directives in which two different | 
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| 151 | *              symbols are specified (the first one is represented here). | 
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| 152 | * | 
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| 153 | * | 
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| 154 | *      n_other == N_BALNAME | 
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| 155 | *              the symbol is the 'bal' entry point to a leaf procedure. | 
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| 156 | *              These entries result from '.leafproc' directives in which only | 
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| 157 | *              one symbol is specified, or in which the same symbol is | 
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| 158 | *              specified twice. | 
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| 159 | * | 
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| 160 | * Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry, | 
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| 161 | * but not every N_BALNAME entry must have an N_CALLNAME entry. | 
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| 162 | */ | 
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| 163 | #define N_CALLNAME      ((char)-1) | 
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| 164 | #define N_BALNAME       ((char)-2) | 
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| 165 | #define IS_CALLNAME(x)  (N_CALLNAME == (x)) | 
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| 166 | #define IS_BALNAME(x)   (N_BALNAME == (x)) | 
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| 167 | #define IS_OTHER(x)     ((x)>0 && (x) <=32) | 
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| 168 |  | 
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| 169 | #define b_out_relocation_info relocation_info | 
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| 170 | struct relocation_info { | 
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| 171 | int      r_address;     /* File address of item to be relocated */ | 
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| 172 | unsigned | 
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| 173 | #define r_index r_symbolnum | 
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| 174 | r_symbolnum:24,/* Index of symbol on which relocation is based, | 
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| 175 | *       if r_extern is set.  Otherwise set to | 
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| 176 | *       either N_TEXT, N_DATA, or N_BSS to | 
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| 177 | *       indicate section on which relocation is | 
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| 178 | *       based. | 
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| 179 | */ | 
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| 180 | r_pcrel:1,      /* 1 => relocate PC-relative; else absolute | 
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| 181 | *      On i960, pc-relative implies 24-bit | 
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| 182 | *      address, absolute implies 32-bit. | 
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| 183 | */ | 
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| 184 | r_length:2,     /* Number of bytes to relocate: | 
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| 185 | *      0 => 1 byte | 
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| 186 | *      1 => 2 bytes -- used for 13 bit pcrel | 
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| 187 | *      2 => 4 bytes | 
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| 188 | */ | 
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| 189 | r_extern:1, | 
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| 190 | r_bsr:1,        /* Something for the GNU NS32K assembler */ | 
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| 191 | r_disp:1,       /* Something for the GNU NS32K assembler */ | 
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| 192 | r_callj:1,      /* 1 if relocation target is an i960 'callj' */ | 
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| 193 | r_relaxable:1;  /* 1 if enough info is left to relax | 
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| 194 | the data */ | 
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| 195 | }; | 
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