1 /* ELF support for BFD.
2    Copyright 1991, 1992, 1993, 1994, 1995, 1997, 1998, 2000, 2001, 2002
3    Free Software Foundation, Inc.
4 
5    Written by Fred Fish @ Cygnus Support, from information published
6    in "UNIX System V Release 4, Programmers Guide: ANSI C and
7    Programming Support Tools".
8 
9 This file is part of BFD, the Binary File Descriptor library.
10 
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2 of the License, or
14 (at your option) any later version.
15 
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 GNU General Public License for more details.
20 
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
24 
25 
26 /* This file is part of ELF support for BFD, and contains the portions
27    that describe how ELF is represented internally in the BFD library.
28    I.E. it describes the in-memory representation of ELF.  It requires
29    the elf-common.h file which contains the portions that are common to
30    both the internal and external representations. */
31 
32 
33 /* NOTE that these structures are not kept in the same order as they appear
34    in the object file.  In some cases they've been reordered for more optimal
35    packing under various circumstances.  */
36 
37 #ifndef _ELF_INTERNAL_H
38 #define _ELF_INTERNAL_H
39 
40 /* ELF Header */
41 
42 #define EI_NIDENT	16		/* Size of e_ident[] */
43 
44 typedef struct elf_internal_ehdr {
45   unsigned char		e_ident[EI_NIDENT]; /* ELF "magic number" */
46   bfd_vma		e_entry;	/* Entry point virtual address */
47   bfd_size_type		e_phoff;	/* Program header table file offset */
48   bfd_size_type		e_shoff;	/* Section header table file offset */
49   unsigned long		e_version;	/* Identifies object file version */
50   unsigned long		e_flags;	/* Processor-specific flags */
51   unsigned short	e_type;		/* Identifies object file type */
52   unsigned short	e_machine;	/* Specifies required architecture */
53   unsigned int		e_ehsize;	/* ELF header size in bytes */
54   unsigned int		e_phentsize;	/* Program header table entry size */
55   unsigned int		e_phnum;	/* Program header table entry count */
56   unsigned int		e_shentsize;	/* Section header table entry size */
57   unsigned int		e_shnum;	/* Section header table entry count */
58   unsigned int		e_shstrndx;	/* Section header string table index */
59 } Elf_Internal_Ehdr;
60 
61 /* Program header */
62 
63 struct elf_internal_phdr {
64   unsigned long	p_type;			/* Identifies program segment type */
65   unsigned long	p_flags;		/* Segment flags */
66   bfd_vma	p_offset;		/* Segment file offset */
67   bfd_vma	p_vaddr;		/* Segment virtual address */
68   bfd_vma	p_paddr;		/* Segment physical address */
69   bfd_vma	p_filesz;		/* Segment size in file */
70   bfd_vma	p_memsz;		/* Segment size in memory */
71   bfd_vma	p_align;		/* Segment alignment, file & memory */
72 };
73 
74 typedef struct elf_internal_phdr Elf_Internal_Phdr;
75 
76 /* Section header */
77 
78 typedef struct elf_internal_shdr {
79   unsigned int	sh_name;		/* Section name, index in string tbl */
80   unsigned int	sh_type;		/* Type of section */
81   bfd_vma	sh_flags;		/* Miscellaneous section attributes */
82   bfd_vma	sh_addr;		/* Section virtual addr at execution */
83   bfd_size_type	sh_size;		/* Size of section in bytes */
84   bfd_size_type	sh_entsize;		/* Entry size if section holds table */
85   unsigned long	sh_link;		/* Index of another section */
86   unsigned long	sh_info;		/* Additional section information */
87   file_ptr	sh_offset;		/* Section file offset */
88   unsigned int	sh_addralign;		/* Section alignment */
89 
90   /* The internal rep also has some cached info associated with it. */
91   asection *	bfd_section;		/* Associated BFD section.  */
92   unsigned char *contents;		/* Section contents.  */
93 } Elf_Internal_Shdr;
94 
95 /* Symbol table entry */
96 
97 struct elf_internal_sym {
98   bfd_vma	st_value;		/* Value of the symbol */
99   bfd_vma	st_size;		/* Associated symbol size */
100   unsigned long	st_name;		/* Symbol name, index in string tbl */
101   unsigned char	st_info;		/* Type and binding attributes */
102   unsigned char	st_other;		/* Visibilty, and target specific */
103   unsigned int  st_shndx;		/* Associated section index */
104 };
105 
106 typedef struct elf_internal_sym Elf_Internal_Sym;
107 
108 /* Note segments */
109 
110 typedef struct elf_internal_note {
111   unsigned long	namesz;			/* Size of entry's owner string */
112   unsigned long	descsz;			/* Size of the note descriptor */
113   unsigned long	type;			/* Interpretation of the descriptor */
114   char *	namedata;		/* Start of the name+desc data */
115   char *	descdata;		/* Start of the desc data */
116   bfd_vma	descpos;		/* File offset of the descdata */
117 } Elf_Internal_Note;
118 
119 /* Relocation Entries */
120 
121 typedef struct elf_internal_rela {
122   bfd_vma	r_offset;	/* Location at which to apply the action */
123   bfd_vma	r_info;		/* Index and Type of relocation */
124   bfd_vma	r_addend;	/* Constant addend used to compute value */
125 } Elf_Internal_Rela;
126 
127 /* dynamic section structure */
128 
129 typedef struct elf_internal_dyn {
130   /* This needs to support 64-bit values in elf64.  */
131   bfd_vma d_tag;		/* entry tag value */
132   union {
133     /* This needs to support 64-bit values in elf64.  */
134     bfd_vma	d_val;
135     bfd_vma	d_ptr;
136   } d_un;
137 } Elf_Internal_Dyn;
138 
139 /* This structure appears in a SHT_GNU_verdef section.  */
140 
141 typedef struct elf_internal_verdef {
142   unsigned short vd_version;	/* Version number of structure.  */
143   unsigned short vd_flags;	/* Flags (VER_FLG_*).  */
144   unsigned short vd_ndx;	/* Version index.  */
145   unsigned short vd_cnt;	/* Number of verdaux entries.  */
146   unsigned long	 vd_hash;	/* Hash of name.  */
147   unsigned long	 vd_aux;	/* Offset to verdaux entries.  */
148   unsigned long	 vd_next;	/* Offset to next verdef.  */
149 
150   /* These fields are set up when BFD reads in the structure.  FIXME:
151      It would be cleaner to store these in a different structure.  */
152   bfd			      *vd_bfd;		/* BFD.  */
153   const char		      *vd_nodename;	/* Version name.  */
154   struct elf_internal_verdef  *vd_nextdef;	/* vd_next as pointer.  */
155   struct elf_internal_verdaux *vd_auxptr;	/* vd_aux as pointer.  */
156   unsigned int		       vd_exp_refno;	/* Used by the linker.  */
157 } Elf_Internal_Verdef;
158 
159 /* This structure appears in a SHT_GNU_verdef section.  */
160 
161 typedef struct elf_internal_verdaux {
162   unsigned long vda_name;	/* String table offset of name.  */
163   unsigned long vda_next;	/* Offset to next verdaux.  */
164 
165   /* These fields are set up when BFD reads in the structure.  FIXME:
166      It would be cleaner to store these in a different structure.  */
167   const char *vda_nodename;			/* vda_name as pointer.  */
168   struct elf_internal_verdaux *vda_nextptr;	/* vda_next as pointer.  */
169 } Elf_Internal_Verdaux;
170 
171 /* This structure appears in a SHT_GNU_verneed section.  */
172 
173 typedef struct elf_internal_verneed {
174   unsigned short vn_version;	/* Version number of structure.  */
175   unsigned short vn_cnt;	/* Number of vernaux entries.  */
176   unsigned long	 vn_file;	/* String table offset of library name.  */
177   unsigned long	 vn_aux;	/* Offset to vernaux entries.  */
178   unsigned long	 vn_next;	/* Offset to next verneed.  */
179 
180   /* These fields are set up when BFD reads in the structure.  FIXME:
181      It would be cleaner to store these in a different structure.  */
182   bfd			      *vn_bfd;		/* BFD.  */
183   const char                  *vn_filename;	/* vn_file as pointer.  */
184   struct elf_internal_vernaux *vn_auxptr;	/* vn_aux as pointer.  */
185   struct elf_internal_verneed *vn_nextref;	/* vn_nextref as pointer.  */
186 } Elf_Internal_Verneed;
187 
188 /* This structure appears in a SHT_GNU_verneed section.  */
189 
190 typedef struct elf_internal_vernaux {
191   unsigned long	 vna_hash;	/* Hash of dependency name.  */
192   unsigned short vna_flags;	/* Flags (VER_FLG_*).  */
193   unsigned short vna_other;	/* Unused.  */
194   unsigned long	 vna_name;	/* String table offset to version name.  */
195   unsigned long	 vna_next;	/* Offset to next vernaux.  */
196 
197   /* These fields are set up when BFD reads in the structure.  FIXME:
198      It would be cleaner to store these in a different structure.  */
199   const char                  *vna_nodename;	/* vna_name as pointer.  */
200   struct elf_internal_vernaux *vna_nextptr;	/* vna_next as pointer.  */
201 } Elf_Internal_Vernaux;
202 
203 /* This structure appears in a SHT_GNU_versym section.  This is not a
204    standard ELF structure; ELF just uses Elf32_Half.  */
205 
206 typedef struct elf_internal_versym {
207   unsigned short vs_vers;
208 } Elf_Internal_Versym;
209 
210 /* Structure for syminfo section.  */
211 typedef struct
212 {
213   unsigned short int 	si_boundto;
214   unsigned short int	si_flags;
215 } Elf_Internal_Syminfo;
216 
217 /* This structure appears on the stack and in NT_AUXV core file notes.  */
218 typedef struct
219 {
220   bfd_vma a_type;
221   bfd_vma a_val;
222 } Elf_Internal_Auxv;
223 
224 
225 /* This structure is used to describe how sections should be assigned
226    to program segments.  */
227 
228 struct elf_segment_map
229 {
230   /* Next program segment.  */
231   struct elf_segment_map *next;
232   /* Program segment type.  */
233   unsigned long p_type;
234   /* Program segment flags.  */
235   unsigned long p_flags;
236   /* Program segment physical address.  */
237   bfd_vma p_paddr;
238   /* Whether the p_flags field is valid; if not, the flags are based
239      on the section flags.  */
240   unsigned int p_flags_valid : 1;
241   /* Whether the p_paddr field is valid; if not, the physical address
242      is based on the section lma values.  */
243   unsigned int p_paddr_valid : 1;
244   /* Whether this segment includes the file header.  */
245   unsigned int includes_filehdr : 1;
246   /* Whether this segment includes the program headers.  */
247   unsigned int includes_phdrs : 1;
248   /* Number of sections (may be 0).  */
249   unsigned int count;
250   /* Sections.  Actual number of elements is in count field.  */
251   asection *sections[1];
252 };
253 
254 #endif /* _ELF_INTERNAL_H */
255