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1 | /* Another try at encapsulating bsd object files in coff. |
2 | Copyright (C) 1988, 1989, Free Software Foundation, Inc. |
3 | Written by Pace Willisson 12/9/88 |
4 | |
5 | This file is free software; you can redistribute it and/or modify |
6 | it under the terms of the GNU General Public License as published by |
7 | the Free Software Foundation; either version 1, or (at your option) |
8 | any later version. |
9 | |
10 | This file is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
13 | GNU General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU General Public License |
16 | along with this file; if not, write to the Free Software |
17 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
18 | |
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19 | /* |
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20 | * This time, we will only use the coff headers to tell the kernel |
21 | * how to exec the file. Therefore, the only fields that need to |
22 | * be filled in are the scnptr and vaddr for the text and data |
23 | * sections, and the vaddr for the bss. As far as coff is concerned, |
24 | * there is no symbol table, relocation, or line numbers. |
25 | * |
26 | * A normal bsd header (struct exec) is placed after the coff headers, |
27 | * and before the real text. I defined a the new fields 'a_machtype' |
28 | * and a_flags. If a_machtype is M_386, and a_flags & A_ENCAP is |
29 | * true, then the bsd header is preceeded by a coff header. Macros |
30 | * like N_TXTOFF and N_TXTADDR use this field to find the bsd header. |
31 | * |
32 | * The only problem is to track down the bsd exec header. The |
33 | * macros HEADER_OFFSET, etc do this. Look at nm.c, dis.c, etc |
34 | * for examples. |
35 | */ |
36 | |
37 | #include "a.out.gnu.h" |
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 | #ifdef i386 |
81 | #define COFF_MAGIC 0514 /* I386MAGIC */ |
82 | #endif |
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83 | #ifdef m68k |
84 | #define COFF_MAGIC 0520 /* MC68MAGIC */ |
85 | #endif |
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86 | |
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87 | #ifdef COFF_MAGIC |
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88 | short __header_offset_temp; |
89 | #define HEADER_OFFSET(f) \ |
90 | (__header_offset_temp = 0, \ |
91 | fread ((char *)&__header_offset_temp, sizeof (short), 1, (f)), \ |
92 | fseek ((f), -sizeof (short), 1), \ |
93 | __header_offset_temp==COFF_MAGIC ? sizeof(struct coffheader) : 0) |
94 | |
95 | #define HEADER_OFFSET_FD(fd) \ |
96 | (__header_offset_temp = 0, \ |
97 | read ((fd), (char *)&__header_offset_temp, sizeof (short)), \ |
98 | lseek ((fd), -sizeof (short), 1), \ |
99 | __header_offset_temp==COFF_MAGIC ? sizeof(struct coffheader) : 0) |
100 | |
101 | |
102 | #else |
103 | #define HEADER_OFFSET(f) 0 |
104 | #define HEADER_OFFSET_FD(fd) 0 |
105 | #endif |
106 | |
107 | #define HEADER_SEEK(f) (fseek ((f), HEADER_OFFSET((f)), 1)) |
108 | #define HEADER_SEEK_FD(fd) (lseek ((fd), HEADER_OFFSET_FD((fd)), 1)) |
109 | |
110 | \f |
111 | /* Describe the characteristics of the BSD header |
112 | that appears inside the encapsulation. */ |
113 | |
114 | #undef _N_HDROFF |
115 | #undef N_TXTADDR |
116 | #undef N_DATADDR |
117 | |
118 | #define _N_HDROFF(x) ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ |
119 | sizeof (struct coffheader) : 0) |
120 | |
121 | /* Address of text segment in memory after it is loaded. */ |
122 | #define N_TXTADDR(x) \ |
123 | ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ |
124 | sizeof (struct coffheader) + sizeof (struct exec) : 0) |
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125 | #define SEGMENT_SIZE 0x400000 |
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126 | |
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127 | #define N_DATADDR(x) \ |
128 | ((N_FLAGS(x) & N_FLAGS_COFF_ENCAPSULATE) ? \ |
129 | (SEGMENT_SIZE + ((N_TXTADDR(x)+(x).a_text-1) & ~(SEGMENT_SIZE-1))) : \ |
130 | (N_TXTADDR(x)+(x).a_text)) |