0,0 → 1,516 |
/* `a.out' object-file definitions, including extensions to 64-bit fields |
|
Copyright 1999, 2000, 2001, 2003, 2009, 2010 Free Software Foundation, Inc. |
|
This program is free software; you can redistribute it and/or modify |
it under the terms of the GNU General Public License as published by |
the Free Software Foundation; either version 3 of the License, or |
(at your option) any later version. |
|
This program is distributed in the hope that it will be useful, |
but WITHOUT ANY WARRANTY; without even the implied warranty of |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
GNU General Public License for more details. |
|
You should have received a copy of the GNU General Public License |
along with this program; if not, write to the Free Software |
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
MA 02110-1301, USA. */ |
|
#ifndef __A_OUT_64_H__ |
#define __A_OUT_64_H__ |
|
#ifndef BYTES_IN_WORD |
#define BYTES_IN_WORD 4 |
#endif |
|
/* This is the layout on disk of the 32-bit or 64-bit exec header. */ |
|
#ifndef external_exec |
struct external_exec |
{ |
bfd_byte e_info[4]; /* Magic number and stuff. */ |
bfd_byte e_text[BYTES_IN_WORD]; /* Length of text section in bytes. */ |
bfd_byte e_data[BYTES_IN_WORD]; /* Length of data section in bytes. */ |
bfd_byte e_bss[BYTES_IN_WORD]; /* Length of bss area in bytes. */ |
bfd_byte e_syms[BYTES_IN_WORD]; /* Length of symbol table in bytes. */ |
bfd_byte e_entry[BYTES_IN_WORD]; /* Start address. */ |
bfd_byte e_trsize[BYTES_IN_WORD]; /* Length of text relocation info. */ |
bfd_byte e_drsize[BYTES_IN_WORD]; /* Length of data relocation info. */ |
}; |
|
#define EXEC_BYTES_SIZE (4 + BYTES_IN_WORD * 7) |
|
/* Magic numbers for a.out files. */ |
|
#if ARCH_SIZE==64 |
#define OMAGIC 0x1001 /* Code indicating object file. */ |
#define ZMAGIC 0x1002 /* Code indicating demand-paged executable. */ |
#define NMAGIC 0x1003 /* Code indicating pure executable. */ |
|
/* There is no 64-bit QMAGIC as far as I know. */ |
|
#define N_BADMAG(x) (N_MAGIC(x) != OMAGIC \ |
&& N_MAGIC(x) != NMAGIC \ |
&& N_MAGIC(x) != ZMAGIC) |
#else |
#define OMAGIC 0407 /* Object file or impure executable. */ |
#define NMAGIC 0410 /* Code indicating pure executable. */ |
#define ZMAGIC 0413 /* Code indicating demand-paged executable. */ |
#define BMAGIC 0415 /* Used by a b.out object. */ |
|
/* This indicates a demand-paged executable with the header in the text. |
It is used by 386BSD (and variants) and Linux, at least. */ |
#ifndef QMAGIC |
#define QMAGIC 0314 |
#endif |
# ifndef N_BADMAG |
# define N_BADMAG(x) (N_MAGIC(x) != OMAGIC \ |
&& N_MAGIC(x) != NMAGIC \ |
&& N_MAGIC(x) != ZMAGIC \ |
&& N_MAGIC(x) != QMAGIC) |
# endif /* N_BADMAG */ |
#endif |
|
#endif |
|
#ifdef QMAGIC |
#define N_IS_QMAGIC(x) (N_MAGIC (x) == QMAGIC) |
#else |
#define N_IS_QMAGIC(x) (0) |
#endif |
|
/* The difference between TARGET_PAGE_SIZE and N_SEGSIZE is that TARGET_PAGE_SIZE is |
the finest granularity at which you can page something, thus it |
controls the padding (if any) before the text segment of a ZMAGIC |
file. N_SEGSIZE is the resolution at which things can be marked as |
read-only versus read/write, so it controls the padding between the |
text segment and the data segment (in memory; on disk the padding |
between them is TARGET_PAGE_SIZE). TARGET_PAGE_SIZE and N_SEGSIZE are the same |
for most machines, but different for sun3. */ |
|
/* By default, segment size is constant. But some machines override this |
to be a function of the a.out header (e.g. machine type). */ |
|
#ifndef N_SEGSIZE |
#define N_SEGSIZE(x) SEGMENT_SIZE |
#endif |
|
/* Virtual memory address of the text section. |
This is getting very complicated. A good reason to discard a.out format |
for something that specifies these fields explicitly. But til then... |
|
* OMAGIC and NMAGIC files: |
(object files: text for "relocatable addr 0" right after the header) |
start at 0, offset is EXEC_BYTES_SIZE, size as stated. |
* The text address, offset, and size of ZMAGIC files depend |
on the entry point of the file: |
* entry point below TEXT_START_ADDR: |
(hack for SunOS shared libraries) |
start at 0, offset is 0, size as stated. |
* If N_HEADER_IN_TEXT(x) is true (which defaults to being the |
case when the entry point is EXEC_BYTES_SIZE or further into a page): |
no padding is needed; text can start after exec header. Sun |
considers the text segment of such files to include the exec header; |
for BFD's purposes, we don't, which makes more work for us. |
start at TEXT_START_ADDR + EXEC_BYTES_SIZE, offset is EXEC_BYTES_SIZE, |
size as stated minus EXEC_BYTES_SIZE. |
* If N_HEADER_IN_TEXT(x) is false (which defaults to being the case when |
the entry point is less than EXEC_BYTES_SIZE into a page (e.g. page |
aligned)): (padding is needed so that text can start at a page boundary) |
start at TEXT_START_ADDR, offset TARGET_PAGE_SIZE, size as stated. |
|
Specific configurations may want to hardwire N_HEADER_IN_TEXT, |
for efficiency or to allow people to play games with the entry point. |
In that case, you would #define N_HEADER_IN_TEXT(x) as 1 for sunos, |
and as 0 for most other hosts (Sony News, Vax Ultrix, etc). |
(Do this in the appropriate bfd target file.) |
(The default is a heuristic that will break if people try changing |
the entry point, perhaps with the ld -e flag.) |
|
* QMAGIC is always like a ZMAGIC for which N_HEADER_IN_TEXT is true, |
and for which the starting address is TARGET_PAGE_SIZE (or should this be |
SEGMENT_SIZE?) (TEXT_START_ADDR only applies to ZMAGIC, not to QMAGIC). */ |
|
/* This macro is only relevant for ZMAGIC files; QMAGIC always has the header |
in the text. */ |
#ifndef N_HEADER_IN_TEXT |
#define N_HEADER_IN_TEXT(x) \ |
(((x).a_entry & (TARGET_PAGE_SIZE-1)) >= EXEC_BYTES_SIZE) |
#endif |
|
/* Sun shared libraries, not linux. This macro is only relevant for ZMAGIC |
files. */ |
#ifndef N_SHARED_LIB |
#define N_SHARED_LIB(x) (0) |
#endif |
|
/* Returning 0 not TEXT_START_ADDR for OMAGIC and NMAGIC is based on |
the assumption that we are dealing with a .o file, not an |
executable. This is necessary for OMAGIC (but means we don't work |
right on the output from ld -N); more questionable for NMAGIC. */ |
|
#ifndef N_TXTADDR |
#define N_TXTADDR(x) \ |
(/* The address of a QMAGIC file is always one page in, \ |
with the header in the text. */ \ |
N_IS_QMAGIC (x) \ |
? (bfd_vma) TARGET_PAGE_SIZE + EXEC_BYTES_SIZE \ |
: (N_MAGIC (x) != ZMAGIC \ |
? (bfd_vma) 0 /* Object file or NMAGIC. */ \ |
: (N_SHARED_LIB (x) \ |
? (bfd_vma) 0 \ |
: (N_HEADER_IN_TEXT (x) \ |
? (bfd_vma) TEXT_START_ADDR + EXEC_BYTES_SIZE \ |
: (bfd_vma) TEXT_START_ADDR)))) |
#endif |
|
/* If N_HEADER_IN_TEXT is not true for ZMAGIC, there is some padding |
to make the text segment start at a certain boundary. For most |
systems, this boundary is TARGET_PAGE_SIZE. But for Linux, in the |
time-honored tradition of crazy ZMAGIC hacks, it is 1024 which is |
not what TARGET_PAGE_SIZE needs to be for QMAGIC. */ |
|
#ifndef ZMAGIC_DISK_BLOCK_SIZE |
#define ZMAGIC_DISK_BLOCK_SIZE TARGET_PAGE_SIZE |
#endif |
|
#define N_DISK_BLOCK_SIZE(x) \ |
(N_MAGIC(x) == ZMAGIC ? ZMAGIC_DISK_BLOCK_SIZE : TARGET_PAGE_SIZE) |
|
/* Offset in an a.out of the start of the text section. */ |
#ifndef N_TXTOFF |
#define N_TXTOFF(x) \ |
(/* For {O,N,Q}MAGIC, no padding. */ \ |
N_MAGIC (x) != ZMAGIC \ |
? EXEC_BYTES_SIZE \ |
: (N_SHARED_LIB (x) \ |
? 0 \ |
: (N_HEADER_IN_TEXT (x) \ |
? EXEC_BYTES_SIZE /* No padding. */ \ |
: ZMAGIC_DISK_BLOCK_SIZE /* A page of padding. */))) |
#endif |
/* Size of the text section. It's always as stated, except that we |
offset it to `undo' the adjustment to N_TXTADDR and N_TXTOFF |
for ZMAGIC files that nominally include the exec header |
as part of the first page of text. (BFD doesn't consider the |
exec header to be part of the text segment.) */ |
#ifndef N_TXTSIZE |
#define N_TXTSIZE(x) \ |
(/* For QMAGIC, we don't consider the header part of the text section. */\ |
N_IS_QMAGIC (x) \ |
? (x).a_text - EXEC_BYTES_SIZE \ |
: ((N_MAGIC (x) != ZMAGIC || N_SHARED_LIB (x)) \ |
? (x).a_text \ |
: (N_HEADER_IN_TEXT (x) \ |
? (x).a_text - EXEC_BYTES_SIZE /* No padding. */ \ |
: (x).a_text /* A page of padding. */ ))) |
#endif |
/* The address of the data segment in virtual memory. |
It is the text segment address, plus text segment size, rounded |
up to a N_SEGSIZE boundary for pure or pageable files. */ |
#ifndef N_DATADDR |
#define N_DATADDR(x) \ |
(N_MAGIC (x) == OMAGIC \ |
? (N_TXTADDR (x) + N_TXTSIZE (x)) \ |
: (N_SEGSIZE (x) + ((N_TXTADDR (x) + N_TXTSIZE (x) - 1) \ |
& ~ (bfd_vma) (N_SEGSIZE (x) - 1)))) |
#endif |
/* The address of the BSS segment -- immediately after the data segment. */ |
|
#define N_BSSADDR(x) (N_DATADDR (x) + (x).a_data) |
|
/* Offsets of the various portions of the file after the text segment. */ |
|
/* For {Q,Z}MAGIC, there is padding to make the data segment start on |
a page boundary. Most of the time the a_text field (and thus |
N_TXTSIZE) already contains this padding. It is possible that for |
BSDI and/or 386BSD it sometimes doesn't contain the padding, and |
perhaps we should be adding it here. But this seems kind of |
questionable and probably should be BSDI/386BSD-specific if we do |
do it. |
|
For NMAGIC (at least for hp300 BSD, probably others), there is |
padding in memory only, not on disk, so we must *not* ever pad here |
for NMAGIC. */ |
|
#ifndef N_DATOFF |
#define N_DATOFF(x) (N_TXTOFF (x) + N_TXTSIZE (x)) |
#endif |
#ifndef N_TRELOFF |
#define N_TRELOFF(x) (N_DATOFF (x) + (x).a_data) |
#endif |
#ifndef N_DRELOFF |
#define N_DRELOFF(x) (N_TRELOFF (x) + (x).a_trsize) |
#endif |
#ifndef N_SYMOFF |
#define N_SYMOFF(x) (N_DRELOFF (x) + (x).a_drsize) |
#endif |
#ifndef N_STROFF |
#define N_STROFF(x) (N_SYMOFF (x) + (x).a_syms) |
#endif |
|
/* Symbols */ |
#ifndef external_nlist |
struct external_nlist |
{ |
bfd_byte e_strx[BYTES_IN_WORD]; /* Index into string table of name. */ |
bfd_byte e_type[1]; /* Type of symbol. */ |
bfd_byte e_other[1]; /* Misc info (usually empty). */ |
bfd_byte e_desc[2]; /* Description field. */ |
bfd_byte e_value[BYTES_IN_WORD]; /* Value of symbol. */ |
}; |
#define EXTERNAL_NLIST_SIZE (BYTES_IN_WORD+4+BYTES_IN_WORD) |
#endif |
|
struct internal_nlist |
{ |
unsigned long n_strx; /* Index into string table of name. */ |
unsigned char n_type; /* Type of symbol. */ |
unsigned char n_other; /* Misc info (usually empty). */ |
unsigned short n_desc; /* Description field. */ |
bfd_vma n_value; /* Value of symbol. */ |
}; |
|
/* The n_type field is the symbol type, containing: */ |
|
#define N_UNDF 0 /* Undefined symbol. */ |
#define N_ABS 2 /* Absolute symbol -- defined at particular addr. */ |
#define N_TEXT 4 /* Text sym -- defined at offset in text seg. */ |
#define N_DATA 6 /* Data sym -- defined at offset in data seg. */ |
#define N_BSS 8 /* BSS sym -- defined at offset in zero'd seg. */ |
#define N_COMM 0x12 /* Common symbol (visible after shared lib dynlink). */ |
#define N_FN 0x1f /* File name of .o file. */ |
#define N_FN_SEQ 0x0C /* N_FN from Sequent compilers (sigh). */ |
/* Note: N_EXT can only be usefully OR-ed with N_UNDF, N_ABS, N_TEXT, |
N_DATA, or N_BSS. When the low-order bit of other types is set, |
(e.g. N_WARNING versus N_FN), they are two different types. */ |
#define N_EXT 1 /* External symbol (as opposed to local-to-this-file). */ |
#define N_TYPE 0x1e |
#define N_STAB 0xe0 /* If any of these bits are on, it's a debug symbol. */ |
|
#define N_INDR 0x0a |
|
/* The following symbols refer to set elements. |
All the N_SET[ATDB] symbols with the same name form one set. |
Space is allocated for the set in the text section, and each set |
elements value is stored into one word of the space. |
The first word of the space is the length of the set (number of elements). |
|
The address of the set is made into an N_SETV symbol |
whose name is the same as the name of the set. |
This symbol acts like a N_DATA global symbol |
in that it can satisfy undefined external references. */ |
|
/* These appear as input to LD, in a .o file. */ |
#define N_SETA 0x14 /* Absolute set element symbol. */ |
#define N_SETT 0x16 /* Text set element symbol. */ |
#define N_SETD 0x18 /* Data set element symbol. */ |
#define N_SETB 0x1A /* Bss set element symbol. */ |
|
/* This is output from LD. */ |
#define N_SETV 0x1C /* Pointer to set vector in data area. */ |
|
/* Warning symbol. The text gives a warning message, the next symbol |
in the table will be undefined. When the symbol is referenced, the |
message is printed. */ |
|
#define N_WARNING 0x1e |
|
/* Weak symbols. These are a GNU extension to the a.out format. The |
semantics are those of ELF weak symbols. Weak symbols are always |
externally visible. The N_WEAK? values are squeezed into the |
available slots. The value of a N_WEAKU symbol is 0. The values |
of the other types are the definitions. */ |
#define N_WEAKU 0x0d /* Weak undefined symbol. */ |
#define N_WEAKA 0x0e /* Weak absolute symbol. */ |
#define N_WEAKT 0x0f /* Weak text symbol. */ |
#define N_WEAKD 0x10 /* Weak data symbol. */ |
#define N_WEAKB 0x11 /* Weak bss symbol. */ |
|
/* Relocations |
|
There are two types of relocation flavours for a.out systems, |
standard and extended. The standard form is used on systems where the |
instruction has room for all the bits of an offset to the operand, whilst |
the extended form is used when an address operand has to be split over n |
instructions. Eg, on the 68k, each move instruction can reference |
the target with a displacement of 16 or 32 bits. On the sparc, move |
instructions use an offset of 14 bits, so the offset is stored in |
the reloc field, and the data in the section is ignored. */ |
|
/* This structure describes a single relocation to be performed. |
The text-relocation section of the file is a vector of these structures, |
all of which apply to the text section. |
Likewise, the data-relocation section applies to the data section. */ |
|
struct reloc_std_external |
{ |
bfd_byte r_address[BYTES_IN_WORD]; /* Offset of of data to relocate. */ |
bfd_byte r_index[3]; /* Symbol table index of symbol. */ |
bfd_byte r_type[1]; /* Relocation type. */ |
}; |
|
#define RELOC_STD_BITS_PCREL_BIG ((unsigned int) 0x80) |
#define RELOC_STD_BITS_PCREL_LITTLE ((unsigned int) 0x01) |
|
#define RELOC_STD_BITS_LENGTH_BIG ((unsigned int) 0x60) |
#define RELOC_STD_BITS_LENGTH_SH_BIG 5 |
#define RELOC_STD_BITS_LENGTH_LITTLE ((unsigned int) 0x06) |
#define RELOC_STD_BITS_LENGTH_SH_LITTLE 1 |
|
#define RELOC_STD_BITS_EXTERN_BIG ((unsigned int) 0x10) |
#define RELOC_STD_BITS_EXTERN_LITTLE ((unsigned int) 0x08) |
|
#define RELOC_STD_BITS_BASEREL_BIG ((unsigned int) 0x08) |
#define RELOC_STD_BITS_BASEREL_LITTLE ((unsigned int) 0x10) |
|
#define RELOC_STD_BITS_JMPTABLE_BIG ((unsigned int) 0x04) |
#define RELOC_STD_BITS_JMPTABLE_LITTLE ((unsigned int) 0x20) |
|
#define RELOC_STD_BITS_RELATIVE_BIG ((unsigned int) 0x02) |
#define RELOC_STD_BITS_RELATIVE_LITTLE ((unsigned int) 0x40) |
|
#define RELOC_STD_SIZE (BYTES_IN_WORD + 3 + 1) /* Bytes per relocation entry. */ |
|
struct reloc_std_internal |
{ |
bfd_vma r_address; /* Address (within segment) to be relocated. */ |
/* The meaning of r_symbolnum depends on r_extern. */ |
unsigned int r_symbolnum:24; |
/* Nonzero means value is a pc-relative offset |
and it should be relocated for changes in its own address |
as well as for changes in the symbol or section specified. */ |
unsigned int r_pcrel:1; |
/* Length (as exponent of 2) of the field to be relocated. |
Thus, a value of 2 indicates 1<<2 bytes. */ |
unsigned int r_length:2; |
/* 1 => relocate with value of symbol. |
r_symbolnum is the index of the symbol |
in files the symbol table. |
0 => relocate with the address of a segment. |
r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS |
(the N_EXT bit may be set also, but signifies nothing). */ |
unsigned int r_extern:1; |
/* The next three bits are for SunOS shared libraries, and seem to |
be undocumented. */ |
unsigned int r_baserel:1; /* Linkage table relative. */ |
unsigned int r_jmptable:1; /* pc-relative to jump table. */ |
unsigned int r_relative:1; /* "relative relocation". */ |
/* unused */ |
unsigned int r_pad:1; /* Padding -- set to zero. */ |
}; |
|
|
/* EXTENDED RELOCS. */ |
|
struct reloc_ext_external |
{ |
bfd_byte r_address[BYTES_IN_WORD]; /* Offset of of data to relocate. */ |
bfd_byte r_index[3]; /* Symbol table index of symbol. */ |
bfd_byte r_type[1]; /* Relocation type. */ |
bfd_byte r_addend[BYTES_IN_WORD]; /* Datum addend. */ |
}; |
|
#ifndef RELOC_EXT_BITS_EXTERN_BIG |
#define RELOC_EXT_BITS_EXTERN_BIG ((unsigned int) 0x80) |
#endif |
|
#ifndef RELOC_EXT_BITS_EXTERN_LITTLE |
#define RELOC_EXT_BITS_EXTERN_LITTLE ((unsigned int) 0x01) |
#endif |
|
#ifndef RELOC_EXT_BITS_TYPE_BIG |
#define RELOC_EXT_BITS_TYPE_BIG ((unsigned int) 0x1F) |
#endif |
|
#ifndef RELOC_EXT_BITS_TYPE_SH_BIG |
#define RELOC_EXT_BITS_TYPE_SH_BIG 0 |
#endif |
|
#ifndef RELOC_EXT_BITS_TYPE_LITTLE |
#define RELOC_EXT_BITS_TYPE_LITTLE ((unsigned int) 0xF8) |
#endif |
|
#ifndef RELOC_EXT_BITS_TYPE_SH_LITTLE |
#define RELOC_EXT_BITS_TYPE_SH_LITTLE 3 |
#endif |
|
/* Bytes per relocation entry. */ |
#define RELOC_EXT_SIZE (BYTES_IN_WORD + 3 + 1 + BYTES_IN_WORD) |
|
enum reloc_type |
{ |
/* Simple relocations. */ |
RELOC_8, /* data[0:7] = addend + sv */ |
RELOC_16, /* data[0:15] = addend + sv */ |
RELOC_32, /* data[0:31] = addend + sv */ |
/* PC-rel displacement. */ |
RELOC_DISP8, /* data[0:7] = addend - pc + sv */ |
RELOC_DISP16, /* data[0:15] = addend - pc + sv */ |
RELOC_DISP32, /* data[0:31] = addend - pc + sv */ |
/* Special. */ |
RELOC_WDISP30, /* data[0:29] = (addend + sv - pc)>>2 */ |
RELOC_WDISP22, /* data[0:21] = (addend + sv - pc)>>2 */ |
RELOC_HI22, /* data[0:21] = (addend + sv)>>10 */ |
RELOC_22, /* data[0:21] = (addend + sv) */ |
RELOC_13, /* data[0:12] = (addend + sv) */ |
RELOC_LO10, /* data[0:9] = (addend + sv) */ |
RELOC_SFA_BASE, |
RELOC_SFA_OFF13, |
/* P.I.C. (base-relative). */ |
RELOC_BASE10, /* Not sure - maybe we can do this the */ |
RELOC_BASE13, /* right way now */ |
RELOC_BASE22, |
/* For some sort of pc-rel P.I.C. (?) */ |
RELOC_PC10, |
RELOC_PC22, |
/* P.I.C. jump table. */ |
RELOC_JMP_TBL, |
/* Reputedly for shared libraries somehow. */ |
RELOC_SEGOFF16, |
RELOC_GLOB_DAT, |
RELOC_JMP_SLOT, |
RELOC_RELATIVE, |
|
RELOC_11, |
RELOC_WDISP2_14, |
RELOC_WDISP19, |
RELOC_HHI22, /* data[0:21] = (addend + sv) >> 42 */ |
RELOC_HLO10, /* data[0:9] = (addend + sv) >> 32 */ |
|
/* 29K relocation types. */ |
RELOC_JUMPTARG, |
RELOC_CONST, |
RELOC_CONSTH, |
|
/* All the new ones I can think of, for sparc v9. */ |
RELOC_64, /* data[0:63] = addend + sv */ |
RELOC_DISP64, /* data[0:63] = addend - pc + sv */ |
RELOC_WDISP21, /* data[0:20] = (addend + sv - pc)>>2 */ |
RELOC_DISP21, /* data[0:20] = addend - pc + sv */ |
RELOC_DISP14, /* data[0:13] = addend - pc + sv */ |
/* Q . |
What are the other ones, |
Since this is a clean slate, can we throw away the ones we dont |
understand ? Should we sort the values ? What about using a |
microcode format like the 68k ? */ |
NO_RELOC |
}; |
|
|
struct reloc_internal |
{ |
bfd_vma r_address; /* Offset of of data to relocate. */ |
long r_index; /* Symbol table index of symbol. */ |
enum reloc_type r_type; /* Relocation type. */ |
bfd_vma r_addend; /* Datum addend. */ |
}; |
|
/* Q. |
Should the length of the string table be 4 bytes or 8 bytes ? |
|
Q. |
What about archive indexes ? */ |
|
#endif /* __A_OUT_64_H__ */ |