| 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 | #define OMAGIC 0407 /* old impure format */
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| 56 | #define NMAGIC 0410 /* read-only text */
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| 57 | #define ZMAGIC 0413 /* demand load format */
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| 58 |
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| 59 | /* FILE HEADER
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| 60 | All 'lengths' are given as a number of bytes.
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| 61 | All 'alignments' are for relinkable files only; an alignment of
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| 62 | 'n' indicates the corresponding segment must begin at an
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| 63 | address that is a multiple of (2**n). */
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| 64 | struct external_exec
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| 65 | {
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| 66 | /* Standard stuff */
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| 67 | unsigned char e_info[4]; /* Identifies this as a b.out file */
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| 68 | unsigned char e_text[4]; /* Length of text */
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| 69 | unsigned char e_data[4]; /* Length of data */
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| 70 | unsigned char e_bss[4]; /* Length of uninitialized data area */
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| 71 | unsigned char e_syms[4]; /* Length of symbol table */
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| 72 | unsigned char e_entry[4]; /* Runtime start address */
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| 73 | unsigned char e_trsize[4]; /* Length of text relocation info */
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| 74 | unsigned char e_drsize[4]; /* Length of data relocation info */
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| 75 |
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| 76 | /* Added for i960 */
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| 77 | unsigned char e_tload[4]; /* Text runtime load address */
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| 78 | unsigned char e_dload[4]; /* Data runtime load address */
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| 79 | unsigned char e_talign[1]; /* Alignment of text segment */
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| 80 | unsigned char e_dalign[1]; /* Alignment of data segment */
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| 81 | unsigned char e_balign[1]; /* Alignment of bss segment */
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| 82 | unsigned char e_relaxable[1];/* Assembled with enough info to allow linker to relax */
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| 83 | };
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| 84 |
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| 85 | #define EXEC_BYTES_SIZE (sizeof (struct external_exec))
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| 86 |
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| 87 | /* These macros use the a_xxx field names, since they operate on the exec
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| 88 | structure after it's been byte-swapped and realigned on the host machine. */
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| 89 | #define N_BADMAG(x) (((x).a_info)!=BMAGIC)
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| 90 | #define N_TXTOFF(x) EXEC_BYTES_SIZE
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| 91 | #define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text )
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| 92 | #define N_TROFF(x) ( N_DATOFF(x) + (x).a_data )
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| 93 | #define N_TRELOFF N_TROFF
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| 94 | #define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize )
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| 95 | #define N_DRELOFF N_DROFF
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| 96 | #define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize )
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| 97 | #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms )
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| 98 | #define N_DATADDR(x) ( (x).a_dload )
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| 99 |
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| 100 | /* Address of text segment in memory after it is loaded. */
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| 101 | #if !defined (N_TXTADDR)
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| 102 | #define N_TXTADDR(x) 0
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| 103 | #endif
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| 104 |
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| 105 | /* A single entry in the symbol table. */
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| 106 | struct nlist
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| 107 | {
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| 108 | union
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| 109 | {
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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 |
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| 115 | unsigned char n_type; /* See below */
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| 116 | char n_other; /* Used in i80960 support -- see below */
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| 117 | short n_desc;
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| 118 | unsigned long n_value;
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| 119 | };
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| 120 |
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| 121 |
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| 122 | /* Legal values of n_type. */
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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 | #define N_CALLNAME ((char)-1)
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| 163 | #define N_BALNAME ((char)-2)
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| 164 | #define IS_CALLNAME(x) (N_CALLNAME == (x))
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| 165 | #define IS_BALNAME(x) (N_BALNAME == (x))
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| 166 | #define IS_OTHER(x) ((x)>0 && (x) <=32)
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| 167 |
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| 168 | #define b_out_relocation_info relocation_info
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| 169 | struct relocation_info
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| 170 | {
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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 | r_pcrel:1, /* 1 => relocate PC-relative; else absolute
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| 180 | On i960, pc-relative implies 24-bit
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| 181 | address, absolute implies 32-bit. */
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| 182 | r_length:2, /* Number of bytes to relocate:
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| 183 | 0 => 1 byte
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| 184 | 1 => 2 bytes -- used for 13 bit pcrel
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| 185 | 2 => 4 bytes. */
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| 186 | r_extern:1,
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| 187 | r_bsr:1, /* Something for the GNU NS32K assembler. */
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| 188 | r_disp:1, /* Something for the GNU NS32K assembler. */
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| 189 | r_callj:1, /* 1 if relocation target is an i960 'callj'. */
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| 190 | r_relaxable:1; /* 1 if enough info is left to relax the data. */
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| 191 | };
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