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      1 /* This file is aout_gnu.h
      2 
      3    Copyright (C) 1987-2016 Free Software Foundation, Inc.
      4 
      5    This file is part of GAS, the GNU Assembler.
      6 
      7    GAS is free software; you can redistribute it and/or modify
      8    it under the terms of the GNU General Public License as published by
      9    the Free Software Foundation; either version 3, or (at your option)
     10    any later version.
     11 
     12    GAS is distributed in the hope that it will be useful,
     13    but WITHOUT ANY WARRANTY; without even the implied warranty of
     14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     15    GNU General Public License for more details.
     16 
     17    You should have received a copy of the GNU General Public License
     18    along with GAS; see the file COPYING.  If not, write to
     19    the Free Software Foundation, 51 Franklin Street - Fifth Floor,
     20    Boston, MA 02110-1301, USA.  */
     21 
     22 #ifndef __A_OUT_GNU_H__
     23 #define __A_OUT_GNU_H__
     24 
     25 /* There are two main flavours of a.out, one which uses the standard
     26    relocations, and one which uses extended relocations.
     27 
     28    Today, the extended reloc uses are
     29    TC_SPARC
     30 
     31    each must define the enum reloc_type
     32 
     33 */
     34 
     35 #define USE_EXTENDED_RELOC defined(TC_SPARC)
     36 
     37 #if defined(TC_SPARC)
     38 enum reloc_type
     39   {
     40     RELOC_8, RELOC_16, RELOC_32,/* simple relocations */
     41     RELOC_DISP8, RELOC_DISP16, RELOC_DISP32,	/* pc-rel displacement */
     42     RELOC_WDISP30, RELOC_WDISP22,
     43     RELOC_HI22, RELOC_22,
     44     RELOC_13, RELOC_LO10,
     45     RELOC_SFA_BASE, RELOC_SFA_OFF13,
     46     RELOC_BASE10, RELOC_BASE13, RELOC_BASE22,	/* P.I.C. (base-relative) */
     47     RELOC_PC10, RELOC_PC22,	/* for some sort of pc-rel P.I.C. (?) */
     48     RELOC_JMP_TBL,		/* P.I.C. jump table */
     49     RELOC_SEGOFF16,		/* reputedly for shared libraries somehow */
     50     RELOC_GLOB_DAT, RELOC_JMP_SLOT, RELOC_RELATIVE,
     51     RELOC_10, RELOC_11,
     52     RELOC_WDISP2_14,
     53     RELOC_WDISP19,
     54     RELOC_HHI22,
     55     RELOC_HLO10,
     56 
     57     /* 29K relocation types */
     58     RELOC_JUMPTARG, RELOC_CONST, RELOC_CONSTH,
     59 
     60     RELOC_WDISP14, RELOC_WDISP21,
     61 
     62     NO_RELOC
     63   };
     64 
     65 #endif /* TC_SPARC */
     66 
     67 #define __GNU_EXEC_MACROS__
     68 
     69 #ifndef __STRUCT_EXEC_OVERRIDE__
     70 
     71 /* This is the layout on disk of a Unix V7, Berkeley, SunOS, Vax Ultrix
     72    "struct exec".  Don't assume that on this machine, the "struct exec"
     73    will lay out the same sizes or alignments.  */
     74 
     75 struct exec_bytes
     76   {
     77     unsigned char a_info[4];
     78     unsigned char a_text[4];
     79     unsigned char a_data[4];
     80     unsigned char a_bss[4];
     81     unsigned char a_syms[4];
     82     unsigned char a_entry[4];
     83     unsigned char a_trsize[4];
     84     unsigned char a_drsize[4];
     85   };
     86 
     87 /* How big the "struct exec" is on disk */
     88 #define	EXEC_BYTES_SIZE	(8 * 4)
     89 
     90 /* This is the layout in memory of a "struct exec" while we process it.  */
     91 
     92 struct exec
     93 {
     94   unsigned long a_info;		/* Use macros N_MAGIC, etc for access */
     95   unsigned a_text;		/* length of text, in bytes */
     96   unsigned a_data;		/* length of data, in bytes */
     97   unsigned a_bss;		/* length of uninitialized data area for file, in bytes */
     98   unsigned a_syms;		/* length of symbol table data in file, in bytes */
     99   unsigned a_entry;		/* start address */
    100   unsigned a_trsize;		/* length of relocation info for text, in bytes */
    101   unsigned a_drsize;		/* length of relocation info for data, in bytes */
    102 };
    103 
    104 #endif /* __STRUCT_EXEC_OVERRIDE__ */
    105 
    106 /* these go in the N_MACHTYPE field */
    107 /* These symbols could be defined by code from Suns...punt 'em */
    108 #undef M_UNKNOWN
    109 #undef M_68010
    110 #undef M_68020
    111 #undef M_SPARC
    112 enum machine_type
    113   {
    114     M_UNKNOWN = 0,
    115     M_68010 = 1,
    116     M_68020 = 2,
    117     M_SPARC = 3,
    118     /* skip a bunch so we don't run into any of sun's numbers */
    119     M_386 = 100,
    120     M_29K = 101,
    121     M_RS6000 = 102,		/* IBM RS/6000 */
    122     M_VAX4K_NETBSD = 150,
    123     /* HP/BSD formats */
    124     M_HP200 = 200,		/* hp200 (68010) BSD binary */
    125     M_HP300 = 300,		/* hp300 (68020+68881) BSD binary */
    126     M_HPUX23 = 0x020C		/* hp200/300 HPUX binary */
    127   };
    128 
    129 #define N_MAGIC(execp) ((execp)->a_info & 0xffff)
    130 #define N_MACHTYPE(execp) ((enum machine_type)(((execp)->a_info >> 16) & 0xff))
    131 #define N_FLAGS(execp) (((execp)->a_info >> 24) & 0xff)
    132 #define N_SET_INFO(execp, magic, type, flags) \
    133     ((execp)->a_info = ((magic) & 0xffff) \
    134      | (((int)(type) & 0xff) << 16) \
    135      | (((flags) & 0xff) << 24))
    136 #define N_SET_MAGIC(execp, magic) \
    137     ((execp)->a_info = (((execp)->a_info & 0xffff0000) | ((magic) & 0xffff)))
    138 
    139 #define N_SET_MACHTYPE(execp, machtype) \
    140     ((execp)->a_info = \
    141      ((execp)->a_info & 0xff00ffff) | ((((int) (machtype)) & 0xff) << 16))
    142 
    143 #define N_SET_FLAGS(execp, flags) \
    144     ((execp)->a_info = \
    145      ((execp)->a_info & 0x00ffffff) | (((flags) & 0xff) << 24))
    146 
    147 /* Code indicating object file or impure executable.  */
    148 #ifndef OMAGIC
    149 #define OMAGIC 0407
    150 #endif
    151 /* Code indicating pure executable.  */
    152 #define NMAGIC 0410
    153 /* Code indicating demand-paged executable.  */
    154 #define ZMAGIC 0413
    155 
    156 /* Virtual Address of text segment from the a.out file.  For OMAGIC,
    157    (almost always "unlinked .o's" these days), should be zero.
    158    For linked files, should reflect reality if we know it.  */
    159 
    160 #ifndef N_TXTADDR
    161 #define N_TXTADDR(x)	(N_MAGIC(x)==OMAGIC? 0 : TEXT_START_ADDR)
    162 #endif
    163 
    164 #ifndef N_BADMAG
    165 #define N_BADMAG(x)	  (N_MAGIC(x) != OMAGIC		\
    166 			   && N_MAGIC(x) != NMAGIC		\
    167 			   && N_MAGIC(x) != ZMAGIC)
    168 #endif
    169 
    170 /* By default, segment size is constant.  But on some machines, it can
    171    be a function of the a.out header (e.g. machine type).  */
    172 #ifndef	N_SEGSIZE
    173 #define	N_SEGSIZE(x)	SEGMENT_SIZE
    174 #endif
    175 
    176 /* This complexity is for encapsulated COFF support */
    177 #ifndef _N_HDROFF
    178 #define _N_HDROFF(x)	(N_SEGSIZE(x) - sizeof (struct exec))
    179 #endif
    180 
    181 #ifndef N_TXTOFF
    182 #define N_TXTOFF(x)	(N_MAGIC(x) == ZMAGIC ?	\
    183 			 _N_HDROFF((x)) + sizeof (struct exec) :	\
    184 			 sizeof (struct exec))
    185 #endif
    186 
    187 #ifndef N_DATOFF
    188 #define N_DATOFF(x)	( N_TXTOFF(x) + (x)->a_text )
    189 #endif
    190 
    191 #ifndef N_TRELOFF
    192 #define N_TRELOFF(x)	( N_DATOFF(x) + (x)->a_data )
    193 #endif
    194 
    195 #ifndef N_DRELOFF
    196 #define N_DRELOFF(x)	( N_TRELOFF(x) + (x)->a_trsize )
    197 #endif
    198 
    199 #ifndef N_SYMOFF
    200 #define N_SYMOFF(x)	( N_DRELOFF(x) + (x)->a_drsize )
    201 #endif
    202 
    203 #ifndef N_STROFF
    204 #define N_STROFF(x)	( N_SYMOFF(x) + (x)->a_syms )
    205 #endif
    206 
    207 /* Address of text segment in memory after it is loaded.  */
    208 #ifndef N_TXTADDR
    209 #define	N_TXTADDR(x)	0
    210 #endif
    211 
    212 #ifndef N_DATADDR
    213 #define N_DATADDR(x) \
    214     (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+(x)->a_text) \
    215      :  (N_SEGSIZE(x) + ((N_TXTADDR(x)+(x)->a_text-1) & ~(N_SEGSIZE(x)-1))))
    216 #endif
    217 
    218 /* Address of bss segment in memory after it is loaded.  */
    219 #define N_BSSADDR(x) (N_DATADDR(x) + (x)->a_data)
    220 
    221 struct nlist
    223   {
    224     union
    225       {
    226 	char *n_name;
    227 	struct nlist *n_next;
    228 	long n_strx;
    229       }
    230     n_un;
    231     unsigned char n_type;
    232     char n_other;
    233     short n_desc;
    234     unsigned long n_value;
    235   };
    236 
    237 #define N_UNDF 0
    238 #define N_ABS 2
    239 #define N_TEXT 4
    240 #define N_DATA 6
    241 #define N_BSS 8
    242 #define	N_COMM	0x12		/* common (visible in shared lib commons) */
    243 #define N_FN 0x1F		/* File name of a .o file */
    244 
    245 /* Note: N_EXT can only usefully be OR-ed with N_UNDF, N_ABS, N_TEXT,
    246    N_DATA, or N_BSS.  When the low-order bit of other types is set,
    247    (e.g. N_WARNING versus N_FN), they are two different types.  */
    248 #define N_EXT 1
    249 #define N_TYPE 036
    250 #define N_STAB 0340
    251 
    252 /* The following type indicates the definition of a symbol as being
    253    an indirect reference to another symbol.  The other symbol
    254    appears as an undefined reference, immediately following this symbol.
    255 
    256    Indirection is asymmetrical.  The other symbol's value will be used
    257    to satisfy requests for the indirect symbol, but not vice versa.
    258    If the other symbol does not have a definition, libraries will
    259    be searched to find a definition.  */
    260 
    261 #define N_INDR 0xa
    262 
    263 /* The following symbols refer to set elements.
    264    All the N_SET[ATDB] symbols with the same name form one set.
    265    Space is allocated for the set in the text section, and each set
    266    element's value is stored into one word of the space.
    267    The first word of the space is the length of the set (number of elements).
    268 
    269    The address of the set is made into an N_SETV symbol
    270    whose name is the same as the name of the set.
    271    This symbol acts like a N_DATA global symbol
    272    in that it can satisfy undefined external references.  */
    273 
    274 /* These appear as input to LD, in a .o file.  */
    275 #define	N_SETA	0x14		/* Absolute set element symbol */
    276 #define	N_SETT	0x16		/* Text set element symbol */
    277 #define	N_SETD	0x18		/* Data set element symbol */
    278 #define	N_SETB	0x1A		/* Bss set element symbol */
    279 
    280 /* This is output from LD.  */
    281 #define N_SETV	0x1C		/* Pointer to set vector in data area.  */
    282 
    283 /* Warning symbol. The text gives a warning message, the next symbol
    284    in the table will be undefined. When the symbol is referenced, the
    285    message is printed.  */
    286 
    287 #define	N_WARNING 0x1e
    288 
    289 /* Weak symbols.  These are a GNU extension to the a.out format.  The
    290    semantics are those of ELF weak symbols.  Weak symbols are always
    291    externally visible.  The N_WEAK? values are squeezed into the
    292    available slots.  The value of a N_WEAKU symbol is 0.  The values
    293    of the other types are the definitions.  */
    294 #define N_WEAKU	0x0d		/* Weak undefined symbol.  */
    295 #define N_WEAKA 0x0e		/* Weak absolute symbol.  */
    296 #define N_WEAKT 0x0f		/* Weak text symbol.  */
    297 #define N_WEAKD 0x10		/* Weak data symbol.  */
    298 #define N_WEAKB 0x11		/* Weak bss symbol.  */
    299 
    300 /* This structure describes a single relocation to be performed.
    302    The text-relocation section of the file is a vector of these structures,
    303    all of which apply to the text section.
    304    Likewise, the data-relocation section applies to the data section.  */
    305 
    306 /* The following enum and struct were borrowed from SunOS's
    307    /usr/include/sun4/a.out.h  and extended to handle
    308    other machines.  It is currently used on SPARC and AMD 29000.
    309 
    310    reloc_ext_bytes is how it looks on disk.  reloc_info_extended is
    311    how we might process it on a native host.  */
    312 #if USE_EXTENDED_RELOC
    313 
    314 struct reloc_ext_bytes
    315   {
    316     unsigned char r_address[4];
    317     unsigned char r_index[3];
    318     unsigned char r_bits[1];
    319     unsigned char r_addend[4];
    320   };
    321 
    322 #define	RELOC_EXT_BITS_EXTERN_BIG	0x80
    323 #define	RELOC_EXT_BITS_EXTERN_LITTLE	0x01
    324 
    325 #define	RELOC_EXT_BITS_TYPE_BIG		0x1F
    326 #define	RELOC_EXT_BITS_TYPE_SH_BIG	0
    327 #define	RELOC_EXT_BITS_TYPE_LITTLE	0xF8
    328 #define	RELOC_EXT_BITS_TYPE_SH_LITTLE	3
    329 
    330 #define	RELOC_EXT_SIZE	12	/* Bytes per relocation entry */
    331 
    332 struct reloc_info_extended
    333 {
    334   unsigned long r_address;
    335   unsigned int r_index:24;
    336 # define	r_symbolnum  r_index
    337   unsigned r_extern:1;
    338   unsigned:2;
    339   /*  RS/6000 compiler does not support enum bitfield
    340 	    enum reloc_type r_type:5; */
    341   enum reloc_type r_type;
    342   long int r_addend;
    343 };
    344 
    345 #else
    346 
    347 /* The standard, old-fashioned, Berkeley compatible relocation struct */
    348 
    349 #ifdef TC_I860
    350 /* NOTE: three bits max, see struct reloc_info_i860.r_type */
    351 enum i860_reloc_type
    352   {
    353     NO_RELOC = 0, BRADDR, LOW0, LOW1, LOW2, LOW3, LOW4, SPLIT0, SPLIT1, SPLIT2, RELOC_32,
    354   };
    355 
    356 typedef enum i860_reloc_type reloc_type;
    357 
    358 /* NOTE: two bits max, see reloc_info_i860.r_type */
    359 enum highlow_type
    360   {
    361     NO_SPEC = 0, PAIR, HIGH, HIGHADJ,
    362   };
    363 
    364 struct reloc_info_i860
    365 {
    366   unsigned long r_address;
    367   /*
    368 	 * Using bit fields here is a bad idea because the order is not portable. :-(
    369 	 */
    370   unsigned int r_symbolnum:24;
    371   unsigned int r_pcrel:1;
    372   unsigned int r_extern:1;
    373   /* combining the two field simplifies the argument passing in "new_fix()" */
    374   /* and is compatible with the existing Sparc #ifdef's */
    375   /* r_type:  highlow_type - bits 5,4; reloc_type - bits 3-0 */
    376   unsigned int r_type:6;
    377   long r_addend;
    378 };
    379 
    380 #endif /* TC_I860 */
    381 
    382 struct reloc_std_bytes
    383   {
    384     unsigned char r_address[4];
    385     unsigned char r_index[3];
    386     unsigned char r_bits[1];
    387   };
    388 
    389 #define	RELOC_STD_BITS_PCREL_BIG	0x80
    390 #define	RELOC_STD_BITS_PCREL_LITTLE	0x01
    391 
    392 #define	RELOC_STD_BITS_LENGTH_BIG	0x60
    393 #define	RELOC_STD_BITS_LENGTH_SH_BIG	5	/* To shift to units place */
    394 #define	RELOC_STD_BITS_LENGTH_LITTLE	0x06
    395 #define	RELOC_STD_BITS_LENGTH_SH_LITTLE	1
    396 
    397 #define	RELOC_STD_BITS_EXTERN_BIG	0x10
    398 #define	RELOC_STD_BITS_EXTERN_LITTLE	0x08
    399 
    400 #define	RELOC_STD_BITS_BASEREL_BIG	0x08
    401 #define	RELOC_STD_BITS_BASEREL_LITTLE	0x08
    402 
    403 #define	RELOC_STD_BITS_JMPTABLE_BIG	0x04
    404 #define	RELOC_STD_BITS_JMPTABLE_LITTLE	0x04
    405 
    406 #define	RELOC_STD_BITS_RELATIVE_BIG	0x02
    407 #define	RELOC_STD_BITS_RELATIVE_LITTLE	0x02
    408 
    409 #define	RELOC_STD_SIZE	8	/* Bytes per relocation entry */
    410 
    411 #endif /* USE_EXTENDED_RELOC */
    412 
    413 #ifndef CUSTOM_RELOC_FORMAT
    414 struct relocation_info
    415 {
    416   /* Address (within segment) to be relocated.  */
    417   int r_address;
    418   /* The meaning of r_symbolnum depends on r_extern.  */
    419   unsigned int r_symbolnum:24;
    420   /* Nonzero means value is a pc-relative offset
    421 	   and it should be relocated for changes in its own address
    422 	   as well as for changes in the symbol or section specified.  */
    423   unsigned int r_pcrel:1;
    424   /* Length (as exponent of 2) of the field to be relocated.
    425 	   Thus, a value of 2 indicates 1<<2 bytes.  */
    426   unsigned int r_length:2;
    427   /* 1 => relocate with value of symbol.
    428 	   r_symbolnum is the index of the symbol
    429 	   in file's the symbol table.
    430 	   0 => relocate with the address of a segment.
    431 	   r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
    432 	   (the N_EXT bit may be set also, but signifies nothing).  */
    433   unsigned int r_extern:1;
    434   /* The next three bits are for SunOS shared libraries, and seem to
    435 	   be undocumented.  */
    436 #ifdef TC_NS32K
    437   unsigned int r_bsr:1;
    438   unsigned int r_disp:2;
    439 #else
    440   unsigned int r_baserel:1;	/* Linkage table relative */
    441   unsigned int r_jmptable:1;	/* pc-relative to jump table */
    442   unsigned int r_relative:1;	/* "relative relocation" */
    443 #endif /* TC_NS32K */
    444   /* unused */
    445   unsigned int r_pad:1;		/* Padding -- set to zero */
    446 };
    447 
    448 #endif /* CUSTOM_RELOC_FORMAT */
    449 
    450 #endif /* __A_OUT_GNU_H__ */
    451 
    452 /* end of aout_gnu.h */
    453