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4f1d9bd8 NC |
1 | /* 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). | |
e4e42b45 | 4 | |
b3adc24a | 5 | Copyright (C) 2001-2020 Free Software Foundation, Inc. |
252b5132 | 6 | |
4f1d9bd8 NC |
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 | |
e4e42b45 | 9 | the Free Software Foundation; either version 3 of the License, or |
4f1d9bd8 | 10 | (at your option) any later version. |
e4e42b45 | 11 | |
4f1d9bd8 NC |
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. | |
e4e42b45 | 16 | |
4f1d9bd8 NC |
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 | |
e4e42b45 NC |
19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
20 | MA 02110-1301, USA. */ | |
4f1d9bd8 NC |
21 | |
22 | /* All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e., | |
23 | object code is generated on, and executed under the direction of a symbolic | |
24 | debugger running on, a host system. We do not want to be subject to the | |
25 | vagaries of which host it is or whether it supports COFF or a.out format, | |
26 | or anything else. We DO want to: | |
27 | ||
28 | o always generate the same format object files, regardless of host. | |
29 | ||
30 | o have an 'a.out' header that we can modify for our own purposes | |
31 | (the 80960 is typically an embedded processor and may require | |
32 | enhanced linker support that the normal a.out.h header can't | |
33 | accommodate). | |
34 | ||
35 | As for byte-ordering, the following rules apply: | |
36 | ||
37 | o Text and data that is actually downloaded to the target is always | |
38 | in i80960 (little-endian) order. | |
39 | ||
40 | o All other numbers (in the header, symbols, relocation directives) | |
41 | are in host byte-order: object files CANNOT be lifted from a | |
42 | little-end host and used on a big-endian (or vice versa) without | |
43 | modification. | |
44 | ==> THIS IS NO LONGER TRUE USING BFD. WE CAN GENERATE ANY BYTE ORDER | |
45 | FOR THE HEADER, AND READ ANY BYTE ORDER. PREFERENCE WOULD BE TO | |
46 | USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST. <== | |
47 | ||
48 | o The downloader ('comm960') takes care to generate a pseudo-header | |
49 | with correct (i80960) byte-ordering before shipping text and data | |
50 | off to the NINDY monitor in the target systems. Symbols and | |
51 | relocation info are never sent to the target. */ | |
252b5132 RH |
52 | |
53 | #define BMAGIC 0415 | |
54 | /* We don't accept the following (see N_BADMAG macro). | |
4f1d9bd8 | 55 | They're just here so GNU code will compile. */ |
252b5132 RH |
56 | #define OMAGIC 0407 /* old impure format */ |
57 | #define NMAGIC 0410 /* read-only text */ | |
58 | #define ZMAGIC 0413 /* demand load format */ | |
59 | ||
60 | /* FILE HEADER | |
4f1d9bd8 NC |
61 | All 'lengths' are given as a number of bytes. |
62 | All 'alignments' are for relinkable files only; an alignment of | |
63 | 'n' indicates the corresponding segment must begin at an | |
64 | address that is a multiple of (2**n). */ | |
65 | struct external_exec | |
66 | { | |
67 | /* Standard stuff */ | |
68 | unsigned char e_info[4]; /* Identifies this as a b.out file */ | |
69 | unsigned char e_text[4]; /* Length of text */ | |
70 | unsigned char e_data[4]; /* Length of data */ | |
71 | unsigned char e_bss[4]; /* Length of uninitialized data area */ | |
72 | unsigned char e_syms[4]; /* Length of symbol table */ | |
73 | unsigned char e_entry[4]; /* Runtime start address */ | |
74 | unsigned char e_trsize[4]; /* Length of text relocation info */ | |
75 | unsigned char e_drsize[4]; /* Length of data relocation info */ | |
252b5132 | 76 | |
4f1d9bd8 NC |
77 | /* Added for i960 */ |
78 | unsigned char e_tload[4]; /* Text runtime load address */ | |
79 | unsigned char e_dload[4]; /* Data runtime load address */ | |
80 | unsigned char e_talign[1]; /* Alignment of text segment */ | |
81 | unsigned char e_dalign[1]; /* Alignment of data segment */ | |
82 | unsigned char e_balign[1]; /* Alignment of bss segment */ | |
83 | unsigned char e_relaxable[1];/* Assembled with enough info to allow linker to relax */ | |
84 | }; | |
252b5132 RH |
85 | |
86 | #define EXEC_BYTES_SIZE (sizeof (struct external_exec)) | |
87 | ||
88 | /* These macros use the a_xxx field names, since they operate on the exec | |
4f1d9bd8 | 89 | structure after it's been byte-swapped and realigned on the host machine. */ |
bbb1afc8 | 90 | #define N_BADMAG(x) (((x)->a_info)!=BMAGIC) |
252b5132 | 91 | #define N_TXTOFF(x) EXEC_BYTES_SIZE |
bbb1afc8 AM |
92 | #define N_DATOFF(x) ( N_TXTOFF(x) + (x)->a_text ) |
93 | #define N_TROFF(x) ( N_DATOFF(x) + (x)->a_data ) | |
252b5132 | 94 | #define N_TRELOFF N_TROFF |
bbb1afc8 | 95 | #define N_DROFF(x) ( N_TROFF(x) + (x)->a_trsize ) |
252b5132 | 96 | #define N_DRELOFF N_DROFF |
bbb1afc8 AM |
97 | #define N_SYMOFF(x) ( N_DROFF(x) + (x)->a_drsize ) |
98 | #define N_STROFF(x) ( N_SYMOFF(x) + (x)->a_syms ) | |
99 | #define N_DATADDR(x) ( (x)->a_dload ) | |
252b5132 RH |
100 | |
101 | /* Address of text segment in memory after it is loaded. */ | |
102 | #if !defined (N_TXTADDR) | |
103 | #define N_TXTADDR(x) 0 | |
104 | #endif | |
105 | ||
4f1d9bd8 NC |
106 | /* A single entry in the symbol table. */ |
107 | struct nlist | |
108 | { | |
109 | union | |
110 | { | |
111 | char* n_name; | |
112 | struct nlist * n_next; | |
113 | long n_strx; /* Index into string table */ | |
114 | } n_un; | |
115 | ||
116 | unsigned char n_type; /* See below */ | |
117 | char n_other; /* Used in i80960 support -- see below */ | |
118 | short n_desc; | |
119 | unsigned long n_value; | |
120 | }; | |
252b5132 RH |
121 | |
122 | ||
4f1d9bd8 | 123 | /* Legal values of n_type. */ |
252b5132 RH |
124 | #define N_UNDF 0 /* Undefined symbol */ |
125 | #define N_ABS 2 /* Absolute symbol */ | |
126 | #define N_TEXT 4 /* Text symbol */ | |
127 | #define N_DATA 6 /* Data symbol */ | |
128 | #define N_BSS 8 /* BSS symbol */ | |
129 | #define N_FN 31 /* Filename symbol */ | |
130 | ||
131 | #define N_EXT 1 /* External symbol (OR'd in with one of above) */ | |
132 | #define N_TYPE 036 /* Mask for all the type bits */ | |
133 | #define N_STAB 0340 /* Mask for all bits used for SDB entries */ | |
134 | ||
135 | /* MEANING OF 'n_other' | |
4f1d9bd8 NC |
136 | |
137 | If non-zero, the 'n_other' fields indicates either a leaf procedure or | |
138 | a system procedure, as follows: | |
139 | ||
140 | 1 <= n_other <= 32 : | |
141 | The symbol is the entry point to a system procedure. | |
142 | 'n_value' is the address of the entry, as for any other | |
143 | procedure. The system procedure number (which can be used in | |
144 | a 'calls' instruction) is (n_other-1). These entries come from | |
145 | '.sysproc' directives. | |
146 | ||
147 | n_other == N_CALLNAME | |
148 | the symbol is the 'call' entry point to a leaf procedure. | |
149 | The *next* symbol in the symbol table must be the corresponding | |
150 | 'bal' entry point to the procedure (see following). These | |
151 | entries come from '.leafproc' directives in which two different | |
152 | symbols are specified (the first one is represented here). | |
153 | ||
154 | ||
155 | n_other == N_BALNAME | |
156 | the symbol is the 'bal' entry point to a leaf procedure. | |
157 | These entries result from '.leafproc' directives in which only | |
158 | one symbol is specified, or in which the same symbol is | |
159 | specified twice. | |
160 | ||
161 | Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry, | |
162 | but not every N_BALNAME entry must have an N_CALLNAME entry. */ | |
252b5132 RH |
163 | #define N_CALLNAME ((char)-1) |
164 | #define N_BALNAME ((char)-2) | |
165 | #define IS_CALLNAME(x) (N_CALLNAME == (x)) | |
166 | #define IS_BALNAME(x) (N_BALNAME == (x)) | |
167 | #define IS_OTHER(x) ((x)>0 && (x) <=32) | |
168 | ||
169 | #define b_out_relocation_info relocation_info | |
4f1d9bd8 NC |
170 | struct relocation_info |
171 | { | |
172 | int r_address; /* File address of item to be relocated. */ | |
173 | unsigned | |
252b5132 | 174 | #define r_index r_symbolnum |
4f1d9bd8 NC |
175 | r_symbolnum:24, /* Index of symbol on which relocation is based, |
176 | if r_extern is set. Otherwise set to | |
177 | either N_TEXT, N_DATA, or N_BSS to | |
178 | indicate section on which relocation is | |
179 | based. */ | |
180 | r_pcrel:1, /* 1 => relocate PC-relative; else absolute | |
181 | On i960, pc-relative implies 24-bit | |
182 | address, absolute implies 32-bit. */ | |
183 | r_length:2, /* Number of bytes to relocate: | |
184 | 0 => 1 byte | |
185 | 1 => 2 bytes -- used for 13 bit pcrel | |
186 | 2 => 4 bytes. */ | |
187 | r_extern:1, | |
188 | r_bsr:1, /* Something for the GNU NS32K assembler. */ | |
189 | r_disp:1, /* Something for the GNU NS32K assembler. */ | |
190 | r_callj:1, /* 1 if relocation target is an i960 'callj'. */ | |
191 | r_relaxable:1; /* 1 if enough info is left to relax the data. */ | |
252b5132 | 192 | }; |