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

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-old/] [gdb-7.1/] [include/] [bout.h] - Blame information for rev 842

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 227 jeremybenn
/* This file is a modified version of 'a.out.h'.  It is to be used in all
2
   GNU tools modified to support the i80960 (or tools that operate on
3
   object files created by such tools).
4
 
5
   Copyright 2001 Free Software Foundation, Inc.
6
 
7
   This program is free software; you can redistribute it and/or modify
8
   it under the terms of the GNU General Public License as published by
9
   the Free Software Foundation; either version 2 of the License, or
10
   (at your option) any later version.
11
 
12
   This program is distributed in the hope that it will be useful,
13
   but WITHOUT ANY WARRANTY; without even the implied warranty of
14
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15
   GNU General Public License for more details.
16
 
17
   You should have received a copy of the GNU General Public License
18
   along with this program; if not, write to the Free Software
19
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
20
 
21
/* All i80960 development is done in a CROSS-DEVELOPMENT environment.  I.e.,
22
   object code is generated on, and executed under the direction of a symbolic
23
   debugger running on, a host system.  We do not want to be subject to the
24
   vagaries of which host it is or whether it supports COFF or a.out format,
25
   or anything else.  We DO want to:
26
 
27
        o always generate the same format object files, regardless of host.
28
 
29
        o have an 'a.out' header that we can modify for our own purposes
30
          (the 80960 is typically an embedded processor and may require
31
          enhanced linker support that the normal a.out.h header can't
32
          accommodate).
33
 
34
  As for byte-ordering, the following rules apply:
35
 
36
        o Text and data that is actually downloaded to the target is always
37
          in i80960 (little-endian) order.
38
 
39
        o All other numbers (in the header, symbols, relocation directives)
40
          are in host byte-order:  object files CANNOT be lifted from a
41
          little-end host and used on a big-endian (or vice versa) without
42
          modification.
43
  ==> THIS IS NO LONGER TRUE USING BFD.  WE CAN GENERATE ANY BYTE ORDER
44
      FOR THE HEADER, AND READ ANY BYTE ORDER.  PREFERENCE WOULD BE TO
45
      USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST.  <==
46
 
47
        o The downloader ('comm960') takes care to generate a pseudo-header
48
          with correct (i80960) byte-ordering before shipping text and data
49
          off to the NINDY monitor in the target systems.  Symbols and
50
          relocation info are never sent to the target.  */
51
 
52
#define BMAGIC  0415
53
/* We don't accept the following (see N_BADMAG macro).
54
   They're just here so GNU code will compile.  */
55
#define OMAGIC  0407            /* old impure format */
56
#define NMAGIC  0410            /* read-only text */
57
#define ZMAGIC  0413            /* demand load format */
58
 
59
/* FILE HEADER
60
        All 'lengths' are given as a number of bytes.
61
        All 'alignments' are for relinkable files only;  an alignment of
62
                'n' indicates the corresponding segment must begin at an
63
                address that is a multiple of (2**n).  */
64
struct external_exec
65
  {
66
    /* Standard stuff */
67
    unsigned char e_info[4];    /* Identifies this as a b.out file */
68
    unsigned char e_text[4];    /* Length of text */
69
    unsigned char e_data[4];    /* Length of data */
70
    unsigned char e_bss[4];     /* Length of uninitialized data area */
71
    unsigned char e_syms[4];    /* Length of symbol table */
72
    unsigned char e_entry[4];   /* Runtime start address */
73
    unsigned char e_trsize[4];  /* Length of text relocation info */
74
    unsigned char e_drsize[4];  /* Length of data relocation info */
75
 
76
    /* Added for i960 */
77
    unsigned char e_tload[4];   /* Text runtime load address */
78
    unsigned char e_dload[4];   /* Data runtime load address */
79
    unsigned char e_talign[1];  /* Alignment of text segment */
80
    unsigned char e_dalign[1];  /* Alignment of data segment */
81
    unsigned char e_balign[1];  /* Alignment of bss segment */
82
    unsigned char e_relaxable[1];/* Assembled with enough info to allow linker to relax */
83
  };
84
 
85
#define EXEC_BYTES_SIZE (sizeof (struct external_exec))
86
 
87
/* These macros use the a_xxx field names, since they operate on the exec
88
   structure after it's been byte-swapped and realigned on the host machine.  */
89
#define N_BADMAG(x)     (((x).a_info)!=BMAGIC)
90
#define N_TXTOFF(x)     EXEC_BYTES_SIZE
91
#define N_DATOFF(x)     ( N_TXTOFF(x) + (x).a_text )
92
#define N_TROFF(x)      ( N_DATOFF(x) + (x).a_data )
93
#define N_TRELOFF       N_TROFF
94
#define N_DROFF(x)      ( N_TROFF(x) + (x).a_trsize )
95
#define N_DRELOFF       N_DROFF
96
#define N_SYMOFF(x)     ( N_DROFF(x) + (x).a_drsize )
97
#define N_STROFF(x)     ( N_SYMOFF(x) + (x).a_syms )
98
#define N_DATADDR(x)    ( (x).a_dload )    
99
 
100
/* Address of text segment in memory after it is loaded.  */
101
#if !defined (N_TXTADDR)
102
#define N_TXTADDR(x) 0
103
#endif
104
 
105
/* A single entry in the symbol table.  */
106
struct nlist
107
  {
108
    union
109
      {
110
        char*          n_name;
111
        struct nlist * n_next;
112
        long           n_strx;  /* Index into string table      */
113
      } n_un;
114
 
115
    unsigned char n_type;       /* See below                            */
116
    char          n_other;      /* Used in i80960 support -- see below  */
117
    short         n_desc;
118
    unsigned long n_value;
119
  };
120
 
121
 
122
/* Legal values of n_type.  */
123
#define N_UNDF  0        /* Undefined symbol     */
124
#define N_ABS   2       /* Absolute symbol      */
125
#define N_TEXT  4       /* Text symbol          */
126
#define N_DATA  6       /* Data symbol          */
127
#define N_BSS   8       /* BSS symbol           */
128
#define N_FN    31      /* Filename symbol      */
129
 
130
#define N_EXT   1       /* External symbol (OR'd in with one of above)  */
131
#define N_TYPE  036     /* Mask for all the type bits                   */
132
#define N_STAB  0340    /* Mask for all bits used for SDB entries       */
133
 
134
/* MEANING OF 'n_other'
135
 
136
  If non-zero, the 'n_other' fields indicates either a leaf procedure or
137
  a system procedure, as follows:
138
 
139
        1 <= n_other <= 32 :
140
                The symbol is the entry point to a system procedure.
141
                'n_value' is the address of the entry, as for any other
142
                procedure.  The system procedure number (which can be used in
143
                a 'calls' instruction) is (n_other-1).  These entries come from
144
                '.sysproc' directives.
145
 
146
        n_other == N_CALLNAME
147
                the symbol is the 'call' entry point to a leaf procedure.
148
                The *next* symbol in the symbol table must be the corresponding
149
                'bal' entry point to the procedure (see following).  These
150
                entries come from '.leafproc' directives in which two different
151
                symbols are specified (the first one is represented here).
152
 
153
 
154
        n_other == N_BALNAME
155
                the symbol is the 'bal' entry point to a leaf procedure.
156
                These entries result from '.leafproc' directives in which only
157
                one symbol is specified, or in which the same symbol is
158
                specified twice.
159
 
160
  Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry,
161
  but not every N_BALNAME entry must have an N_CALLNAME entry.  */
162
#define N_CALLNAME      ((char)-1)
163
#define N_BALNAME       ((char)-2)
164
#define IS_CALLNAME(x)  (N_CALLNAME == (x))
165
#define IS_BALNAME(x)   (N_BALNAME == (x))
166
#define IS_OTHER(x)     ((x)>0 && (x) <=32)
167
 
168
#define b_out_relocation_info relocation_info
169
struct relocation_info
170
  {
171
    int  r_address;     /* File address of item to be relocated.  */
172
    unsigned
173
#define r_index r_symbolnum
174
    r_symbolnum:24,     /* Index of symbol on which relocation is based,
175
                           if r_extern is set.  Otherwise set to
176
                           either N_TEXT, N_DATA, or N_BSS to
177
                           indicate section on which relocation is
178
                           based.  */
179
      r_pcrel:1,        /* 1 => relocate PC-relative; else absolute
180
                           On i960, pc-relative implies 24-bit
181
                           address, absolute implies 32-bit.  */
182
      r_length:2,       /* Number of bytes to relocate:
183
 
184
                           1 => 2 bytes -- used for 13 bit pcrel
185
                           2 => 4 bytes.  */
186
      r_extern:1,
187
      r_bsr:1,          /* Something for the GNU NS32K assembler.  */
188
      r_disp:1,         /* Something for the GNU NS32K assembler.  */
189
      r_callj:1,        /* 1 if relocation target is an i960 'callj'.  */
190
      r_relaxable:1;    /* 1 if enough info is left to relax the data.  */
191
};

powered by: WebSVN 2.1.0

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