OpenCores
URL https://opencores.org/ocsvn/or1k/or1k/trunk

Subversion Repositories or1k

[/] [or1k/] [trunk/] [gdb-5.0/] [gdb/] [nindy-share/] [b.out.h] - Blame information for rev 1765

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 106 markom
/*  Copyright 1992 Free Software Foundation, Inc.
2
 *
3
 * This file is a modified version of 'a.out.h'.  It is to be used in all
4
 * all GNU tools modified to support the i80960 (or tools that operate on
5
 * object files created by such tools).
6
 *
7
 * All i80960 development is done in a CROSS-DEVELOPMENT environment.  I.e.,
8
 * object code is generated on, and executed under the direction of a symbolic
9
 * debugger running on, a host system.  We do not want to be subject to the
10
 * vagaries of which host it is or whether it supports COFF or a.out format,
11
 * or anything else.  We DO want to:
12
 *
13
 *      o always generate the same format object files, regardless of host.
14
 *
15
 *      o have an 'a.out' header that we can modify for our own purposes
16
 *        (the 80960 is typically an embedded processor and may require
17
 *        enhanced linker support that the normal a.out.h header can't
18
 *        accommodate).
19
 *
20
 * As for byte-ordering, the following rules apply:
21
 *
22
 *      o Text and data that is actually downloaded to the target is always
23
 *        in i80960 (little-endian) order.
24
 *
25
 *      o All other numbers (in the header, symbols, relocation directives)
26
 *        are in host byte-order:  object files CANNOT be lifted from a
27
 *        little-end host and used on a big-endian (or vice versa) without
28
 *        modification.
29
 *
30
 *      o The downloader ('comm960') takes care to generate a pseudo-header
31
 *        with correct (i80960) byte-ordering before shipping text and data
32
 *        off to the NINDY monitor in the target systems.  Symbols and
33
 *        relocation info are never sent to the target.
34
 */
35
 
36
 
37
#define BMAGIC  0415
38
/* We don't accept the following (see N_BADMAG macro).
39
 * They're just here so GNU code will compile.
40
 */
41
#define OMAGIC  0407            /* old impure format */
42
#define NMAGIC  0410            /* read-only text */
43
#define ZMAGIC  0413            /* demand load format */
44
 
45
/* FILE HEADER
46
 *      All 'lengths' are given as a number of bytes.
47
 *      All 'alignments' are for relinkable files only;  an alignment of
48
 *              'n' indicates the corresponding segment must begin at an
49
 *              address that is a multiple of (2**n).
50
 */
51
struct exec {
52
        /* Standard stuff */
53
        unsigned long a_magic;  /* Identifies this as a b.out file      */
54
        unsigned long a_text;   /* Length of text                       */
55
        unsigned long a_data;   /* Length of data                       */
56
        unsigned long a_bss;    /* Length of runtime uninitialized data area */
57
        unsigned long a_syms;   /* Length of symbol table               */
58
        unsigned long a_entry;  /* Runtime start address                */
59
        unsigned long a_trsize; /* Length of text relocation info       */
60
        unsigned long a_drsize; /* Length of data relocation info       */
61
 
62
        /* Added for i960 */
63
        unsigned long a_tload;  /* Text runtime load address            */
64
        unsigned long a_dload;  /* Data runtime load address            */
65
        unsigned char a_talign; /* Alignment of text segment            */
66
        unsigned char a_dalign; /* Alignment of data segment            */
67
        unsigned char a_balign; /* Alignment of bss segment             */
68
        unsigned char unused;   /* (Just to make struct size a multiple of 4) */
69
};
70
 
71
#define N_BADMAG(x)     (((x).a_magic)!=BMAGIC)
72
#define N_TXTOFF(x)     ( sizeof(struct exec) )
73
#define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text )
74
#define N_TROFF(x)      ( N_DATOFF(x) + (x).a_data )
75
#define N_DROFF(x)      ( N_TROFF(x) + (x).a_trsize )
76
#define N_SYMOFF(x)     ( N_DROFF(x) + (x).a_drsize )
77
#define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
78
 
79
/* A single entry in the symbol table
80
 */
81
struct nlist {
82
        union {
83
                char    *n_name;
84
                struct nlist *n_next;
85
                long    n_strx;         /* Index into string table      */
86
        } n_un;
87
        unsigned char n_type;   /* See below                            */
88
        char    n_other;        /* Used in i80960 support -- see below  */
89
        short   n_desc;
90
        unsigned long n_value;
91
};
92
 
93
 
94
/* Legal values of n_type
95
 */
96
#define N_UNDF  0        /* Undefined symbol     */
97
#define N_ABS   2       /* Absolute symbol      */
98
#define N_TEXT  4       /* Text symbol          */
99
#define N_DATA  6       /* Data symbol          */
100
#define N_BSS   8       /* BSS symbol           */
101
#define N_FN    31      /* Filename symbol      */
102
 
103
#define N_EXT   1       /* External symbol (OR'd in with one of above)  */
104
#define N_TYPE  036     /* Mask for all the type bits                   */
105
#define N_STAB  0340    /* Mask for all bits used for SDB entries       */
106
 
107
/* MEANING OF 'n_other'
108
 *
109
 * If non-zero, the 'n_other' fields indicates either a leaf procedure or
110
 * a system procedure, as follows:
111
 *
112
 *      1 <= n_other <= 32 :
113
 *              The symbol is the entry point to a system procedure.
114
 *              'n_value' is the address of the entry, as for any other
115
 *              procedure.  The system procedure number (which can be used in
116
 *              a 'calls' instruction) is (n_other-1).  These entries come from
117
 *              '.sysproc' directives.
118
 *
119
 *      n_other == N_CALLNAME
120
 *              the symbol is the 'call' entry point to a leaf procedure.
121
 *              The *next* symbol in the symbol table must be the corresponding
122
 *              'bal' entry point to the procedure (see following).  These
123
 *              entries come from '.leafproc' directives in which two different
124
 *              symbols are specified (the first one is represented here).
125
 *
126
 *
127
 *      n_other == N_BALNAME
128
 *              the symbol is the 'bal' entry point to a leaf procedure.
129
 *              These entries result from '.leafproc' directives in which only
130
 *              one symbol is specified, or in which the same symbol is
131
 *              specified twice.
132
 *
133
 * Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry,
134
 * but not every N_BALNAME entry must have an N_CALLNAME entry.
135
 */
136
#define N_CALLNAME      -1
137
#define N_BALNAME       -2
138
 
139
 
140
struct relocation_info {
141
        int      r_address;     /* File address of item to be relocated */
142
        unsigned
143
                r_symbolnum:24,/* Index of symbol on which relocation is based*/
144
                r_pcrel:1,      /* 1 => relocate PC-relative; else absolute
145
                                 *      On i960, pc-relative implies 24-bit
146
                                 *      address, absolute implies 32-bit.
147
                                 */
148
                r_length:2,     /* Number of bytes to relocate:
149
                                 *      0 => 1 byte
150
                                 *      1 => 2 bytes
151
                                 *      2 => 4 bytes -- only value used for i960
152
                                 */
153
                r_extern:1,
154
                r_bsr:1,        /* Something for the GNU NS32K assembler */
155
                r_disp:1,       /* Something for the GNU NS32K assembler */
156
                r_callj:1,      /* 1 if relocation target is an i960 'callj' */
157
                nuthin:1;       /* Unused                               */
158
};

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.