1 /* `a.out.adobe' differences from standard a.out files
2 
3    Copyright (C) 2001-2016 Free Software Foundation, Inc.
4 
5    This program 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 3 of the License, or
8    (at your option) any later version.
9 
10    This program 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 program; if not, write to the Free Software
17    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
18    MA 02110-1301, USA.  */
19 
20 #ifndef __A_OUT_ADOBE_H__
21 #define __A_OUT_ADOBE_H__
22 
23 #define	BYTES_IN_WORD	4
24 
25 /* Struct external_exec is the same.  */
26 
27 /* This is the layout on disk of the 32-bit or 64-bit exec header. */
28 
29 struct external_exec
30 {
31   bfd_byte e_info[4];		/* magic number and stuff		*/
32   bfd_byte e_text[BYTES_IN_WORD]; /* length of text section in bytes	*/
33   bfd_byte e_data[BYTES_IN_WORD]; /* length of data section in bytes	*/
34   bfd_byte e_bss[BYTES_IN_WORD]; /* length of bss area in bytes 	*/
35   bfd_byte e_syms[BYTES_IN_WORD]; /* length of symbol table in bytes 	*/
36   bfd_byte e_entry[BYTES_IN_WORD]; /* start address 			*/
37   bfd_byte e_trsize[BYTES_IN_WORD]; /* length of text relocation info	*/
38   bfd_byte e_drsize[BYTES_IN_WORD]; /* length of data relocation info 	*/
39 };
40 
41 #define	EXEC_BYTES_SIZE	(4 + BYTES_IN_WORD * 7)
42 
43 /* Magic numbers for a.out files */
44 
45 #undef	ZMAGIC
46 #define	ZMAGIC	0xAD0BE		/* Cute, eh?  */
47 #undef	OMAGIC
48 #undef	NMAGIC
49 
50 #define N_BADMAG(x)	  ((x)->a_info != ZMAGIC)
51 
52 /* By default, segment size is constant.  But some machines override this
53    to be a function of the a.out header (e.g. machine type).  */
54 #ifndef	N_SEGSIZE
55 #define	N_SEGSIZE(x)	SEGMENT_SIZE
56 #endif
57 #undef N_SEGSIZE   /* FIXMEXXXX */
58 
59 /* Segment information for the a.out.Adobe format is specified after the
60    file header.  It contains N segment descriptors, followed by one with
61    a type of zero.
62 
63    The actual text of the segments starts at N_TXTOFF in the file,
64    regardless of how many or how few segment headers there are.  */
65 
66 struct external_segdesc {
67 	unsigned char e_type[1];
68 	unsigned char e_size[3];
69 	unsigned char e_virtbase[4];
70 	unsigned char e_filebase[4];
71 };
72 
73 struct internal_segdesc {
74 	unsigned int	a_type:8;	/* Segment type N_TEXT, N_DATA, 0 */
75 	unsigned int 	a_size:24;	/* Segment size */
76 	bfd_vma		a_virtbase;	/* Virtual address */
77 	unsigned int	a_filebase;	/* Base address in object file */
78 };
79 
80 #define N_TXTADDR(x) is_this_really_unused?
81 
82 /* This is documented to be at 1024, but appears to really be at 2048.
83    FIXME?!  */
84 #define N_TXTOFF(x)	2048
85 
86 #define	N_TXTSIZE(x) ((x)->a_text)
87 
88 #define N_DATADDR(x) is_this_really_unused?
89 
90 #define N_BSSADDR(x) is_this_really_unused?
91 
92 /* Offsets of the various portions of the file after the text segment.  */
93 
94 #define N_DATOFF(x)	( N_TXTOFF(x) + N_TXTSIZE(x) )
95 #define N_TRELOFF(x)	( N_DATOFF(x) + (x)->a_data )
96 #define N_DRELOFF(x)	( N_TRELOFF(x) + (x)->a_trsize )
97 #define N_SYMOFF(x)	( N_DRELOFF(x) + (x)->a_drsize )
98 #define N_STROFF(x)	( N_SYMOFF(x) + (x)->a_syms )
99 
100 /* Symbols */
101 struct external_nlist {
102   bfd_byte e_strx[BYTES_IN_WORD];	/* index into string table of name */
103   bfd_byte e_type[1];			/* type of symbol */
104   bfd_byte e_other[1];			/* misc info (usually empty) */
105   bfd_byte e_desc[2];			/* description field */
106   bfd_byte e_value[BYTES_IN_WORD];	/* value of symbol */
107 };
108 
109 #define EXTERNAL_NLIST_SIZE (BYTES_IN_WORD+4+BYTES_IN_WORD)
110 
111 struct internal_nlist {
112   unsigned long n_strx;			/* index into string table of name */
113   unsigned char n_type;			/* type of symbol */
114   unsigned char n_other;		/* misc info (usually empty) */
115   unsigned short n_desc;		/* description field */
116   bfd_vma n_value;			/* value of symbol */
117 };
118 
119 /* The n_type field is the symbol type, containing:  */
120 
121 #define N_UNDF	0	/* Undefined symbol */
122 #define N_ABS 	2	/* Absolute symbol -- defined at particular addr */
123 #define N_TEXT 	4	/* Text sym -- defined at offset in text seg */
124 #define N_DATA 	6	/* Data sym -- defined at offset in data seg */
125 #define N_BSS 	8	/* BSS  sym -- defined at offset in zero'd seg */
126 #define	N_COMM	0x12	/* Common symbol (visible after shared lib dynlink) */
127 #define N_FN	0x1f	/* File name of .o file */
128 #define	N_FN_SEQ 0x0C	/* N_FN from Sequent compilers (sigh) */
129 /* Note: N_EXT can only be usefully OR-ed with N_UNDF, N_ABS, N_TEXT,
130    N_DATA, or N_BSS.  When the low-order bit of other types is set,
131    (e.g. N_WARNING versus N_FN), they are two different types.  */
132 #define N_EXT 	1	/* External symbol (as opposed to local-to-this-file) */
133 #define N_TYPE  0x1e
134 #define N_STAB 	0xe0	/* If any of these bits are on, it's a debug symbol */
135 
136 #define N_INDR 0x0a
137 
138 /* The following symbols refer to set elements.
139    All the N_SET[ATDB] symbols with the same name form one set.
140    Space is allocated for the set in the text section, and each set
141    elements value is stored into one word of the space.
142    The first word of the space is the length of the set (number of elements).
143 
144    The address of the set is made into an N_SETV symbol
145    whose name is the same as the name of the set.
146    This symbol acts like a N_DATA global symbol
147    in that it can satisfy undefined external references.  */
148 
149 /* These appear as input to LD, in a .o file.  */
150 #define	N_SETA	0x14		/* Absolute set element symbol */
151 #define	N_SETT	0x16		/* Text set element symbol */
152 #define	N_SETD	0x18		/* Data set element symbol */
153 #define	N_SETB	0x1A		/* Bss set element symbol */
154 
155 /* This is output from LD.  */
156 #define N_SETV	0x1C		/* Pointer to set vector in data area.  */
157 
158 /* Warning symbol. The text gives a warning message, the next symbol
159    in the table will be undefined. When the symbol is referenced, the
160    message is printed.  */
161 
162 #define	N_WARNING 0x1e
163 
164 /* Relocations
165 
166   There	are two types of relocation flavours for a.out systems,
167   standard and extended. The standard form is used on systems where the
168   instruction has room for all the bits of an offset to the operand, whilst
169   the extended form is used when an address operand has to be split over n
170   instructions. Eg, on the 68k, each move instruction can reference
171   the target with a displacement of 16 or 32 bits. On the sparc, move
172   instructions use an offset of 14 bits, so the offset is stored in
173   the reloc field, and the data in the section is ignored.
174 */
175 
176 /* This structure describes a single relocation to be performed.
177    The text-relocation section of the file is a vector of these structures,
178    all of which apply to the text section.
179    Likewise, the data-relocation section applies to the data section.  */
180 
181 struct reloc_std_external {
182   bfd_byte r_address[BYTES_IN_WORD];	/* offset of of data to relocate */
183   bfd_byte r_index[3];	/* symbol table index of symbol 	*/
184   bfd_byte r_type[1];	/* relocation type			*/
185 };
186 
187 #define	RELOC_STD_BITS_PCREL_BIG	0x80
188 #define	RELOC_STD_BITS_PCREL_LITTLE	0x01
189 
190 #define	RELOC_STD_BITS_LENGTH_BIG	0x60
191 #define	RELOC_STD_BITS_LENGTH_SH_BIG	5	/* To shift to units place */
192 #define	RELOC_STD_BITS_LENGTH_LITTLE	0x06
193 #define	RELOC_STD_BITS_LENGTH_SH_LITTLE	1
194 
195 #define	RELOC_STD_BITS_EXTERN_BIG	0x10
196 #define	RELOC_STD_BITS_EXTERN_LITTLE	0x08
197 
198 #define	RELOC_STD_BITS_BASEREL_BIG	0x08
199 #define	RELOC_STD_BITS_BASEREL_LITTLE	0x08
200 
201 #define	RELOC_STD_BITS_JMPTABLE_BIG	0x04
202 #define	RELOC_STD_BITS_JMPTABLE_LITTLE	0x04
203 
204 #define	RELOC_STD_BITS_RELATIVE_BIG	0x02
205 #define	RELOC_STD_BITS_RELATIVE_LITTLE	0x02
206 
207 #define	RELOC_STD_SIZE	(BYTES_IN_WORD + 3 + 1)		/* Bytes per relocation entry */
208 
209 struct reloc_std_internal
210 {
211   bfd_vma r_address;		/* Address (within segment) to be relocated.  */
212   /* The meaning of r_symbolnum depends on r_extern.  */
213   unsigned int r_symbolnum:24;
214   /* Nonzero means value is a pc-relative offset
215      and it should be relocated for changes in its own address
216      as well as for changes in the symbol or section specified.  */
217   unsigned int r_pcrel:1;
218   /* Length (as exponent of 2) of the field to be relocated.
219      Thus, a value of 2 indicates 1<<2 bytes.  */
220   unsigned int r_length:2;
221   /* 1 => relocate with value of symbol.
222      r_symbolnum is the index of the symbol
223      in files the symbol table.
224      0 => relocate with the address of a segment.
225      r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
226      (the N_EXT bit may be set also, but signifies nothing).  */
227   unsigned int r_extern:1;
228   /* The next three bits are for SunOS shared libraries, and seem to
229      be undocumented.  */
230   unsigned int r_baserel:1;	/* Linkage table relative */
231   unsigned int r_jmptable:1;	/* pc-relative to jump table */
232   unsigned int r_relative:1;	/* "relative relocation" */
233   /* unused */
234   unsigned int r_pad:1;		/* Padding -- set to zero */
235 };
236 
237 
238 /* EXTENDED RELOCS  */
239 
240 struct reloc_ext_external {
241   bfd_byte r_address[BYTES_IN_WORD];	/* offset of of data to relocate 	*/
242   bfd_byte r_index[3];	/* symbol table index of symbol 	*/
243   bfd_byte r_type[1];	/* relocation type			*/
244   bfd_byte r_addend[BYTES_IN_WORD];	/* datum addend				*/
245 };
246 
247 #define	RELOC_EXT_BITS_EXTERN_BIG	0x80
248 #define	RELOC_EXT_BITS_EXTERN_LITTLE	0x01
249 
250 #define	RELOC_EXT_BITS_TYPE_BIG		0x1F
251 #define	RELOC_EXT_BITS_TYPE_SH_BIG	0
252 #define	RELOC_EXT_BITS_TYPE_LITTLE	0xF8
253 #define	RELOC_EXT_BITS_TYPE_SH_LITTLE	3
254 
255 /* Bytes per relocation entry */
256 #define	RELOC_EXT_SIZE	(BYTES_IN_WORD + 3 + 1 + BYTES_IN_WORD)
257 
258 enum reloc_type
259 {
260   /* simple relocations */
261   RELOC_8,			/* data[0:7] = addend + sv 		*/
262   RELOC_16,			/* data[0:15] = addend + sv 		*/
263   RELOC_32,			/* data[0:31] = addend + sv 		*/
264   /* pc-rel displacement */
265   RELOC_DISP8,			/* data[0:7] = addend - pc + sv 	*/
266   RELOC_DISP16,			/* data[0:15] = addend - pc + sv 	*/
267   RELOC_DISP32,			/* data[0:31] = addend - pc + sv 	*/
268   /* Special */
269   RELOC_WDISP30,		/* data[0:29] = (addend + sv - pc)>>2 	*/
270   RELOC_WDISP22,		/* data[0:21] = (addend + sv - pc)>>2 	*/
271   RELOC_HI22,			/* data[0:21] = (addend + sv)>>10 	*/
272   RELOC_22,			/* data[0:21] = (addend + sv) 		*/
273   RELOC_13,			/* data[0:12] = (addend + sv)		*/
274   RELOC_LO10,			/* data[0:9] = (addend + sv)		*/
275   RELOC_SFA_BASE,
276   RELOC_SFA_OFF13,
277   /* P.I.C. (base-relative) */
278   RELOC_BASE10,  		/* Not sure - maybe we can do this the */
279   RELOC_BASE13,			/* right way now */
280   RELOC_BASE22,
281   /* for some sort of pc-rel P.I.C. (?) */
282   RELOC_PC10,
283   RELOC_PC22,
284   /* P.I.C. jump table */
285   RELOC_JMP_TBL,
286   /* reputedly for shared libraries somehow */
287   RELOC_SEGOFF16,
288   RELOC_GLOB_DAT,
289   RELOC_JMP_SLOT,
290   RELOC_RELATIVE,
291 
292   RELOC_11,
293   RELOC_WDISP2_14,
294   RELOC_WDISP19,
295   RELOC_HHI22,			/* data[0:21] = (addend + sv) >> 42     */
296   RELOC_HLO10,			/* data[0:9] = (addend + sv) >> 32      */
297 
298   /* 29K relocation types */
299   RELOC_JUMPTARG,
300   RELOC_CONST,
301   RELOC_CONSTH,
302 
303   NO_RELOC
304   };
305 
306 
307 struct reloc_internal {
308   bfd_vma r_address;		/* offset of of data to relocate 	*/
309   long	r_index;		/* symbol table index of symbol 	*/
310   enum reloc_type r_type;	/* relocation type			*/
311   bfd_vma r_addend;		/* datum addend				*/
312 };
313 
314 #endif				/* __A_OUT_ADOBE_H__ */
315