xref: /freebsd/sys/amd64/include/elf.h (revision a220d00e74dd245b4fca59c5eca0c53963686325)
1 /*-
2  * Copyright (c) 1996-1997 John D. Polstra.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _MACHINE_ELF_H_
30 #define	_MACHINE_ELF_H_ 1
31 
32 /*
33  * ELF definitions for the i386 architecture.
34  */
35 
36 #include <sys/elf32.h>	/* Definitions common to all 32 bit architectures. */
37 
38 #define	__ELF_WORD_SIZE	32	/* Used by <sys/elf_generic.h> */
39 #include <sys/elf_generic.h>
40 
41 #define	ELF_ARCH	EM_386
42 
43 #define	ELF_MACHINE_OK(x) ((x) == EM_386 || (x) == EM_486)
44 
45 /*
46  * Auxiliary vector entries for passing information to the interpreter.
47  *
48  * The i386 supplement to the SVR4 ABI specification names this "auxv_t",
49  * but POSIX lays claim to all symbols ending with "_t".
50  */
51 
52 typedef struct {	/* Auxiliary vector entry on initial stack */
53 	int	a_type;			/* Entry type. */
54 	union {
55 		long	a_val;		/* Integer value. */
56 		void	*a_ptr;		/* Address. */
57 		void	(*a_fcn)(void);	/* Function pointer (not used). */
58 	} a_un;
59 } Elf32_Auxinfo;
60 
61 __ElfType(Auxinfo);
62 
63 /*
64  * Types of dynamic symbol hash table bucket and chain elements.
65  *
66  * This is inconsistent among 64 bit architectures, so a machine dependent
67  * typedef is required.
68  */
69 
70 typedef Elf32_Off Elf32_Hashelt;
71 
72 __ElfType(Hashelt);
73 
74 /* Values for a_type. */
75 #define	AT_NULL		0	/* Terminates the vector. */
76 #define	AT_IGNORE	1	/* Ignored entry. */
77 #define	AT_EXECFD	2	/* File descriptor of program to load. */
78 #define	AT_PHDR		3	/* Program header of program already loaded. */
79 #define	AT_PHENT	4	/* Size of each program header entry. */
80 #define	AT_PHNUM	5	/* Number of program header entries. */
81 #define	AT_PAGESZ	6	/* Page size in bytes. */
82 #define	AT_BASE		7	/* Interpreter's base address. */
83 #define	AT_FLAGS	8	/* Flags (unused for i386). */
84 #define	AT_ENTRY	9	/* Where interpreter should transfer control. */
85 
86 /*
87  * The following non-standard values are used for passing information
88  * from John Polstra's testbed program to the dynamic linker.  These
89  * are expected to go away soon.
90  *
91  * Unfortunately, these overlap the Linux non-standard values, so they
92  * must not be used in the same context.
93  */
94 #define	AT_BRK		10	/* Starting point for sbrk and brk. */
95 #define	AT_DEBUG	11	/* Debugging level. */
96 
97 /*
98  * The following non-standard values are used in Linux ELF binaries.
99  */
100 #define	AT_NOTELF	10	/* Program is not ELF ?? */
101 #define	AT_UID		11	/* Real uid. */
102 #define	AT_EUID		12	/* Effective uid. */
103 #define	AT_GID		13	/* Real gid. */
104 #define	AT_EGID		14	/* Effective gid. */
105 
106 #define	AT_COUNT	15	/* Count of defined aux entry types. */
107 
108 /*
109  * Relocation types.
110  */
111 
112 #define	R_386_NONE	0	/* No relocation. */
113 #define	R_386_32	1	/* Add symbol value. */
114 #define	R_386_PC32	2	/* Add PC-relative symbol value. */
115 #define	R_386_GOT32	3	/* Add PC-relative GOT offset. */
116 #define	R_386_PLT32	4	/* Add PC-relative PLT offset. */
117 #define	R_386_COPY	5	/* Copy data from shared object. */
118 #define	R_386_GLOB_DAT	6	/* Set GOT entry to data address. */
119 #define	R_386_JMP_SLOT	7	/* Set GOT entry to code address. */
120 #define	R_386_RELATIVE	8	/* Add load address of shared object. */
121 #define	R_386_GOTOFF	9	/* Add GOT-relative symbol address. */
122 #define	R_386_GOTPC	10	/* Add PC-relative GOT table address. */
123 
124 #define	R_386_COUNT	11	/* Count of defined relocation types. */
125 
126 /* Define "machine" characteristics */
127 #define	ELF_TARG_CLASS	ELFCLASS32
128 #define	ELF_TARG_DATA	ELFDATA2LSB
129 #define	ELF_TARG_MACH	EM_386
130 #define	ELF_TARG_VER	1
131 
132 #ifdef _KERNEL
133 
134 /*
135  * On the i386 we load the dynamic linker where a userland call
136  * to mmap(0, ...) would put it.  The rationale behind this
137  * calculation is that it leaves room for the heap to grow to
138  * its maximum allowed size.
139  */
140 #define ELF_RTLD_ADDR(vmspace) \
141     (round_page((vm_offset_t)(vmspace)->vm_daddr + maxdsiz))
142 
143 #endif /* _KERNEL */
144 #endif /* !_MACHINE_ELF_H_ */
145