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252b5132 | 1 | /* Yet Another Try at encapsulating bsd object files in coff. |
4f1d9bd8 | 2 | Copyright 1988, 1989, 1991 Free Software Foundation, Inc. |
252b5132 RH |
3 | Written by Pace Willisson 12/9/88 |
4 | ||
5 | This file is obsolete. It needs to be converted to just define a bunch | |
6 | of stuff that BFD can use to do coff-encapsulated files. --gnu@cygnus.com | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
e172dbf8 | 20 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
252b5132 RH |
21 | |
22 | /* | |
23 | * We only use the coff headers to tell the kernel | |
24 | * how to exec the file. Therefore, the only fields that need to | |
25 | * be filled in are the scnptr and vaddr for the text and data | |
26 | * sections, and the vaddr for the bss. As far as coff is concerned, | |
27 | * there is no symbol table, relocation, or line numbers. | |
28 | * | |
29 | * A normal bsd header (struct exec) is placed after the coff headers, | |
30 | * and before the real text. I defined a the new fields 'a_machtype' | |
31 | * and a_flags. If a_machtype is M_386, and a_flags & A_ENCAP is | |
32 | * true, then the bsd header is preceeded by a coff header. Macros | |
33 | * like N_TXTOFF and N_TXTADDR use this field to find the bsd header. | |
34 | * | |
35 | * The only problem is to track down the bsd exec header. The | |
36 | * macros HEADER_OFFSET, etc do this. | |
37 | */ | |
38 | ||
39 | #define N_FLAGS_COFF_ENCAPSULATE 0x20 /* coff header precedes bsd header */ | |
40 | ||
41 | /* Describe the COFF header used for encapsulation. */ | |
42 | ||
43 | struct coffheader | |
44 | { | |
45 | /* filehdr */ | |
46 | unsigned short f_magic; | |
47 | unsigned short f_nscns; | |
48 | long f_timdat; | |
49 | long f_symptr; | |
50 | long f_nsyms; | |
51 | unsigned short f_opthdr; | |
52 | unsigned short f_flags; | |
53 | /* aouthdr */ | |
54 | short magic; | |
55 | short vstamp; | |
56 | long tsize; | |
57 | long dsize; | |
58 | long bsize; | |
59 | long entry; | |
60 | long text_start; | |
61 | long data_start; | |
62 | struct coffscn | |
63 | { | |
64 | char s_name[8]; | |
65 | long s_paddr; | |
66 | long s_vaddr; | |
67 | long s_size; | |
68 | long s_scnptr; | |
69 | long s_relptr; | |
70 | long s_lnnoptr; | |
71 | unsigned short s_nreloc; | |
72 | unsigned short s_nlnno; | |
73 | long s_flags; | |
74 | } scns[3]; | |
75 | }; | |
76 | \f | |
77 | /* Describe some of the parameters of the encapsulation, | |
78 | including how to find the encapsulated BSD header. */ | |
79 | ||
80 | /* FIXME, this is dumb. The same tools can't handle a.outs for different | |
81 | architectures, just because COFF_MAGIC is different; so you need a | |
82 | separate GNU nm for every architecture!!? Unfortunately, it needs to | |
83 | be this way, since the COFF_MAGIC value is determined by the kernel | |
84 | we're trying to fool here. */ | |
85 | ||
86 | #define COFF_MAGIC_I386 0514 /* I386MAGIC */ | |
87 | #define COFF_MAGIC_M68K 0520 /* MC68MAGIC */ | |
252b5132 RH |
88 | |
89 | #ifdef COFF_MAGIC | |
90 | short __header_offset_temp; | |
91 | #define HEADER_OFFSET(f) \ | |
92 | (__header_offset_temp = 0, \ | |
93 | fread ((char *)&__header_offset_temp, sizeof (short), 1, (f)), \ | |
94 | fseek ((f), -sizeof (short), 1), \ | |
95 | __header_offset_temp==COFF_MAGIC ? sizeof(struct coffheader) : 0) | |
96 | #else | |
97 | #define HEADER_OFFSET(f) 0 | |
98 | #endif | |
99 | ||
100 | #define HEADER_SEEK(f) (fseek ((f), HEADER_OFFSET((f)), 1)) | |
101 | \f | |
102 | /* Describe the characteristics of the BSD header | |
103 | that appears inside the encapsulation. */ | |
104 | ||
105 | /* Encapsulated coff files that are linked ZMAGIC have a text segment | |
106 | offset just past the header (and a matching TXTADDR), excluding | |
107 | the headers from the text segment proper but keeping the physical | |
108 | layout and the virtual memory layout page-aligned. | |
109 | ||
110 | Non-encapsulated a.out files that are linked ZMAGIC have a text | |
111 | segment that starts at 0 and an N_TXTADR similarly offset to 0. | |
112 | They too are page-aligned with each other, but they include the | |
113 | a.out header as part of the text. | |
114 | ||
115 | The _N_HDROFF gets sizeof struct exec added to it, so we have | |
116 | to compensate here. See <a.out.gnu.h>. */ | |
117 | ||
118 | #undef _N_HDROFF | |
119 | #undef N_TXTADDR | |
120 | #undef N_DATADDR | |
121 | ||
122 | #define _N_HDROFF(x) ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ | |
123 | sizeof (struct coffheader) : 0) | |
124 | ||
125 | /* Address of text segment in memory after it is loaded. */ | |
126 | #define N_TXTADDR(x) \ | |
127 | ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ | |
128 | sizeof (struct coffheader) + sizeof (struct exec) : 0) | |
129 | #define SEGMENT_SIZE 0x400000 | |
130 | ||
131 | #define N_DATADDR(x) \ | |
132 | ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ | |
133 | (SEGMENT_SIZE + ((N_TXTADDR(x)+(x).a_text-1) & ~(SEGMENT_SIZE-1))) : \ | |
134 | (N_TXTADDR(x)+(x).a_text)) |