~drizzle-trunk/drizzle/development : revision 8

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/* `a.out' object-file definitions, including extensions to 64-bit fields */

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#ifndef __A_OUT_64_H__

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#define __A_OUT_64_H__

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/* This is the layout on disk of the 32-bit or 64-bit exec header. */

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#ifndef external_exec

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struct external_exec

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{

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bfd_byte e_info[4]; /* magic number and stuff */

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bfd_byte e_text[BYTES_IN_WORD]; /* length of text section in bytes */

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bfd_byte e_data[BYTES_IN_WORD]; /* length of data section in bytes */

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bfd_byte e_bss[BYTES_IN_WORD]; /* length of bss area in bytes */

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bfd_byte e_syms[BYTES_IN_WORD]; /* length of symbol table in bytes */

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bfd_byte e_entry[BYTES_IN_WORD]; /* start address */

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bfd_byte e_trsize[BYTES_IN_WORD]; /* length of text relocation info */

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bfd_byte e_drsize[BYTES_IN_WORD]; /* length of data relocation info */

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};

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#define EXEC_BYTES_SIZE (4 + BYTES_IN_WORD * 7)

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/* Magic numbers for a.out files */

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#if ARCH_SIZE==64

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#define OMAGIC 0x1001 /* Code indicating object file */

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#define ZMAGIC 0x1002 /* Code indicating demand-paged executable. */

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#define NMAGIC 0x1003 /* Code indicating pure executable. */

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/* There is no 64-bit QMAGIC as far as I know. */

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#define N_BADMAG(x) (N_MAGIC(x) != OMAGIC \

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&& N_MAGIC(x) != NMAGIC \

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&& N_MAGIC(x) != ZMAGIC)

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#else

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#define OMAGIC 0407 /* ...object file or impure executable. */

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#define NMAGIC 0410 /* Code indicating pure executable. */

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#define ZMAGIC 0413 /* Code indicating demand-paged executable. */

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#define BMAGIC 0415 /* Used by a b.out object. */

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/* This indicates a demand-paged executable with the header in the text.

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It is used by 386BSD (and variants) and Linux, at least. */

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#ifndef QMAGIC

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#define QMAGIC 0314

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#endif

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# ifndef N_BADMAG

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# define N_BADMAG(x) (N_MAGIC(x) != OMAGIC \

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&& N_MAGIC(x) != NMAGIC \

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&& N_MAGIC(x) != ZMAGIC \

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&& N_MAGIC(x) != QMAGIC)

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# endif /* N_BADMAG */

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#endif

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#endif

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#ifdef QMAGIC

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#define N_IS_QMAGIC(x) (N_MAGIC (x) == QMAGIC)

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#else

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#define N_IS_QMAGIC(x) (0)

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#endif

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/* The difference between TARGET_PAGE_SIZE and N_SEGSIZE is that TARGET_PAGE_SIZE is

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the finest granularity at which you can page something, thus it

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controls the padding (if any) before the text segment of a ZMAGIC

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file. N_SEGSIZE is the resolution at which things can be marked as

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read-only versus read/write, so it controls the padding between the

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text segment and the data segment (in memory; on disk the padding

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between them is TARGET_PAGE_SIZE). TARGET_PAGE_SIZE and N_SEGSIZE are the same

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for most machines, but different for sun3. */

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/* By default, segment size is constant. But some machines override this

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to be a function of the a.out header (e.g. machine type). */

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#ifndef N_SEGSIZE

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#define N_SEGSIZE(x) SEGMENT_SIZE

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#endif

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/* Virtual memory address of the text section.

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This is getting very complicated. A good reason to discard a.out format

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for something that specifies these fields explicitly. But til then...

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* OMAGIC and NMAGIC files:

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(object files: text for "relocatable addr 0" right after the header)

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start at 0, offset is EXEC_BYTES_SIZE, size as stated.

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* The text address, offset, and size of ZMAGIC files depend

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on the entry point of the file:

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* entry point below TEXT_START_ADDR:

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(hack for SunOS shared libraries)

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start at 0, offset is 0, size as stated.

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* If N_HEADER_IN_TEXT(x) is true (which defaults to being the

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case when the entry point is EXEC_BYTES_SIZE or further into a page):

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no padding is needed; text can start after exec header. Sun

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considers the text segment of such files to include the exec header;

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for BFD's purposes, we don't, which makes more work for us.

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start at TEXT_START_ADDR + EXEC_BYTES_SIZE, offset is EXEC_BYTES_SIZE,

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size as stated minus EXEC_BYTES_SIZE.

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* If N_HEADER_IN_TEXT(x) is false (which defaults to being the case when

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the entry point is less than EXEC_BYTES_SIZE into a page (e.g. page

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aligned)): (padding is needed so that text can start at a page boundary)

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start at TEXT_START_ADDR, offset TARGET_PAGE_SIZE, size as stated.

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Specific configurations may want to hardwire N_HEADER_IN_TEXT,

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for efficiency or to allow people to play games with the entry point.

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In that case, you would #define N_HEADER_IN_TEXT(x) as 1 for sunos,

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and as 0 for most other hosts (Sony News, Vax Ultrix, etc).

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(Do this in the appropriate bfd target file.)

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(The default is a heuristic that will break if people try changing

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the entry point, perhaps with the ld -e flag.)

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* QMAGIC is always like a ZMAGIC for which N_HEADER_IN_TEXT is true,

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and for which the starting address is TARGET_PAGE_SIZE (or should this be

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SEGMENT_SIZE?) (TEXT_START_ADDR only applies to ZMAGIC, not to QMAGIC).

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*/

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/* This macro is only relevant for ZMAGIC files; QMAGIC always has the header

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in the text. */

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#ifndef N_HEADER_IN_TEXT

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#define N_HEADER_IN_TEXT(x) (((x).a_entry & (TARGET_PAGE_SIZE-1)) >= EXEC_BYTES_SIZE)

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#endif

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/* Sun shared libraries, not linux. This macro is only relevant for ZMAGIC

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files. */

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#ifndef N_SHARED_LIB

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#define N_SHARED_LIB(x) ((x).a_entry < TEXT_START_ADDR)

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#endif

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/* Returning 0 not TEXT_START_ADDR for OMAGIC and NMAGIC is based on

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the assumption that we are dealing with a .o file, not an

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executable. This is necessary for OMAGIC (but means we don't work

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right on the output from ld -N); more questionable for NMAGIC. */

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#ifndef N_TXTADDR

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#define N_TXTADDR(x) \

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(/* The address of a QMAGIC file is always one page in, */ \

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/* with the header in the text. */ \

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N_IS_QMAGIC (x) ? TARGET_PAGE_SIZE + EXEC_BYTES_SIZE : \

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N_MAGIC(x) != ZMAGIC ? 0 : /* object file or NMAGIC */\

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N_SHARED_LIB(x) ? 0 : \

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N_HEADER_IN_TEXT(x) ? \

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TEXT_START_ADDR + EXEC_BYTES_SIZE : /* no padding */\

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TEXT_START_ADDR /* a page of padding */\

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)

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#endif

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/* If N_HEADER_IN_TEXT is not true for ZMAGIC, there is some padding

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to make the text segment start at a certain boundary. For most

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systems, this boundary is TARGET_PAGE_SIZE. But for Linux, in the

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time-honored tradition of crazy ZMAGIC hacks, it is 1024 which is

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not what TARGET_PAGE_SIZE needs to be for QMAGIC. */

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#ifndef ZMAGIC_DISK_BLOCK_SIZE

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#define ZMAGIC_DISK_BLOCK_SIZE TARGET_PAGE_SIZE

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#endif

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#define N_DISK_BLOCK_SIZE(x) \

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(N_MAGIC(x) == ZMAGIC ? ZMAGIC_DISK_BLOCK_SIZE : TARGET_PAGE_SIZE)

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/* Offset in an a.out of the start of the text section. */

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#ifndef N_TXTOFF

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#define N_TXTOFF(x) \

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(/* For {O,N,Q}MAGIC, no padding. */ \

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N_MAGIC(x) != ZMAGIC ? EXEC_BYTES_SIZE : \

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N_SHARED_LIB(x) ? 0 : \

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N_HEADER_IN_TEXT(x) ? \

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EXEC_BYTES_SIZE : /* no padding */\

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ZMAGIC_DISK_BLOCK_SIZE /* a page of padding */\

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)

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#endif

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/* Size of the text section. It's always as stated, except that we

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offset it to `undo' the adjustment to N_TXTADDR and N_TXTOFF

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for ZMAGIC files that nominally include the exec header

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as part of the first page of text. (BFD doesn't consider the

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exec header to be part of the text segment.) */

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#ifndef N_TXTSIZE

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#define N_TXTSIZE(x) \

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(/* For QMAGIC, we don't consider the header part of the text section. */\

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N_IS_QMAGIC (x) ? (x).a_text - EXEC_BYTES_SIZE : \

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(N_MAGIC(x) != ZMAGIC || N_SHARED_LIB(x)) ? (x).a_text : \

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N_HEADER_IN_TEXT(x) ? \

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(x).a_text - EXEC_BYTES_SIZE: /* no padding */\

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(x).a_text /* a page of padding */\

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)

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#endif

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/* The address of the data segment in virtual memory.

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It is the text segment address, plus text segment size, rounded

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up to a N_SEGSIZE boundary for pure or pageable files. */

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#ifndef N_DATADDR

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#define N_DATADDR(x) \

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(N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+N_TXTSIZE(x)) \

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: (N_SEGSIZE(x) + ((N_TXTADDR(x)+N_TXTSIZE(x)-1) & ~(N_SEGSIZE(x)-1))))

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#endif

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/* The address of the BSS segment -- immediately after the data segment. */

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#define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)

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/* Offsets of the various portions of the file after the text segment. */

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/* For {Q,Z}MAGIC, there is padding to make the data segment start on

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a page boundary. Most of the time the a_text field (and thus

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N_TXTSIZE) already contains this padding. It is possible that for

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BSDI and/or 386BSD it sometimes doesn't contain the padding, and

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perhaps we should be adding it here. But this seems kind of

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questionable and probably should be BSDI/386BSD-specific if we do

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do it.

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For NMAGIC (at least for hp300 BSD, probably others), there is

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padding in memory only, not on disk, so we must *not* ever pad here

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for NMAGIC. */

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#ifndef N_DATOFF

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#define N_DATOFF(x) \

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(N_TXTOFF(x) + N_TXTSIZE(x))

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#endif

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#ifndef N_TRELOFF

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#define N_TRELOFF(x) ( N_DATOFF(x) + (x).a_data )

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#endif

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#ifndef N_DRELOFF

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#define N_DRELOFF(x) ( N_TRELOFF(x) + (x).a_trsize )

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#endif

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#ifndef N_SYMOFF

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#define N_SYMOFF(x) ( N_DRELOFF(x) + (x).a_drsize )

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#endif

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#ifndef N_STROFF

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#define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms )

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#endif

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/* Symbols */

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#ifndef external_nlist

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struct external_nlist {

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bfd_byte e_strx[BYTES_IN_WORD]; /* index into string table of name */

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bfd_byte e_type[1]; /* type of symbol */

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bfd_byte e_other[1]; /* misc info (usually empty) */

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bfd_byte e_desc[2]; /* description field */

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bfd_byte e_value[BYTES_IN_WORD]; /* value of symbol */

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};

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#define EXTERNAL_NLIST_SIZE (BYTES_IN_WORD+4+BYTES_IN_WORD)

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#endif

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struct internal_nlist {

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unsigned long n_strx; /* index into string table of name */

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unsigned char n_type; /* type of symbol */

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unsigned char n_other; /* misc info (usually empty) */

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unsigned short n_desc; /* description field */

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bfd_vma n_value; /* value of symbol */

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};

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/* The n_type field is the symbol type, containing: */

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#define N_UNDF 0 /* Undefined symbol */

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#define N_ABS 2 /* Absolute symbol -- defined at particular addr */

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#define N_TEXT 4 /* Text sym -- defined at offset in text seg */

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#define N_DATA 6 /* Data sym -- defined at offset in data seg */

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#define N_BSS 8 /* BSS sym -- defined at offset in zero'd seg */

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#define N_COMM 0x12 /* Common symbol (visible after shared lib dynlink) */

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#define N_FN 0x1f /* File name of .o file */

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#define N_FN_SEQ 0x0C /* N_FN from Sequent compilers (sigh) */

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/* Note: N_EXT can only be usefully OR-ed with N_UNDF, N_ABS, N_TEXT,

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N_DATA, or N_BSS. When the low-order bit of other types is set,

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(e.g. N_WARNING versus N_FN), they are two different types. */

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#define N_EXT 1 /* External symbol (as opposed to local-to-this-file) */

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#define N_TYPE 0x1e

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#define N_STAB 0xe0 /* If any of these bits are on, it's a debug symbol */

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#define N_INDR 0x0a

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/* The following symbols refer to set elements.

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All the N_SET[ATDB] symbols with the same name form one set.

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Space is allocated for the set in the text section, and each set

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elements value is stored into one word of the space.

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The first word of the space is the length of the set (number of elements).

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The address of the set is made into an N_SETV symbol

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whose name is the same as the name of the set.

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This symbol acts like a N_DATA global symbol

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in that it can satisfy undefined external references. */

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/* These appear as input to LD, in a .o file. */

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#define N_SETA 0x14 /* Absolute set element symbol */

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#define N_SETT 0x16 /* Text set element symbol */

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#define N_SETD 0x18 /* Data set element symbol */

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#define N_SETB 0x1A /* Bss set element symbol */

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/* This is output from LD. */

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#define N_SETV 0x1C /* Pointer to set vector in data area. */

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/* Warning symbol. The text gives a warning message, the next symbol

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in the table will be undefined. When the symbol is referenced, the

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message is printed. */

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#define N_WARNING 0x1e

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/* Weak symbols. These are a GNU extension to the a.out format. The

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semantics are those of ELF weak symbols. Weak symbols are always

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externally visible. The N_WEAK? values are squeezed into the

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available slots. The value of a N_WEAKU symbol is 0. The values

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of the other types are the definitions. */

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#define N_WEAKU 0x0d /* Weak undefined symbol. */

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#define N_WEAKA 0x0e /* Weak absolute symbol. */

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#define N_WEAKT 0x0f /* Weak text symbol. */

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#define N_WEAKD 0x10 /* Weak data symbol. */

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#define N_WEAKB 0x11 /* Weak bss symbol. */

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/* Relocations

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There are two types of relocation flavours for a.out systems,

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standard and extended. The standard form is used on systems where the

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instruction has room for all the bits of an offset to the operand, whilst

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the extended form is used when an address operand has to be split over n

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instructions. Eg, on the 68k, each move instruction can reference

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the target with a displacement of 16 or 32 bits. On the sparc, move

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instructions use an offset of 14 bits, so the offset is stored in

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the reloc field, and the data in the section is ignored.

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*/

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/* This structure describes a single relocation to be performed.

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The text-relocation section of the file is a vector of these structures,

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all of which apply to the text section.

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Likewise, the data-relocation section applies to the data section. */

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struct reloc_std_external {

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bfd_byte r_address[BYTES_IN_WORD]; /* offset of of data to relocate */

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bfd_byte r_index[3]; /* symbol table index of symbol */

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bfd_byte r_type[1]; /* relocation type */

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};

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#define RELOC_STD_BITS_PCREL_BIG ((unsigned int) 0x80)

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#define RELOC_STD_BITS_PCREL_LITTLE ((unsigned int) 0x01)

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#define RELOC_STD_BITS_LENGTH_BIG ((unsigned int) 0x60)

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#define RELOC_STD_BITS_LENGTH_SH_BIG 5

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#define RELOC_STD_BITS_LENGTH_LITTLE ((unsigned int) 0x06)

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#define RELOC_STD_BITS_LENGTH_SH_LITTLE 1

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#define RELOC_STD_BITS_EXTERN_BIG ((unsigned int) 0x10)

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#define RELOC_STD_BITS_EXTERN_LITTLE ((unsigned int) 0x08)

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#define RELOC_STD_BITS_BASEREL_BIG ((unsigned int) 0x08)

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#define RELOC_STD_BITS_BASEREL_LITTLE ((unsigned int) 0x10)

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#define RELOC_STD_BITS_JMPTABLE_BIG ((unsigned int) 0x04)

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#define RELOC_STD_BITS_JMPTABLE_LITTLE ((unsigned int) 0x20)

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#define RELOC_STD_BITS_RELATIVE_BIG ((unsigned int) 0x02)

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#define RELOC_STD_BITS_RELATIVE_LITTLE ((unsigned int) 0x40)

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#define RELOC_STD_SIZE (BYTES_IN_WORD + 3 + 1) /* Bytes per relocation entry */

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struct reloc_std_internal

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{

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bfd_vma r_address; /* Address (within segment) to be relocated. */

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/* The meaning of r_symbolnum depends on r_extern. */

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unsigned int r_symbolnum:24;

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/* Nonzero means value is a pc-relative offset

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and it should be relocated for changes in its own address

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as well as for changes in the symbol or section specified. */

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unsigned int r_pcrel:1;

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/* Length (as exponent of 2) of the field to be relocated.

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Thus, a value of 2 indicates 1<<2 bytes. */

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unsigned int r_length:2;

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/* 1 => relocate with value of symbol.

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r_symbolnum is the index of the symbol

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in files the symbol table.

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0 => relocate with the address of a segment.

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r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS

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(the N_EXT bit may be set also, but signifies nothing). */

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unsigned int r_extern:1;

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/* The next three bits are for SunOS shared libraries, and seem to

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be undocumented. */

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unsigned int r_baserel:1; /* Linkage table relative */

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unsigned int r_jmptable:1; /* pc-relative to jump table */

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unsigned int r_relative:1; /* "relative relocation" */

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/* unused */

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unsigned int r_pad:1; /* Padding -- set to zero */

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};

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/* EXTENDED RELOCS */

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struct reloc_ext_external {

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bfd_byte r_address[BYTES_IN_WORD]; /* offset of of data to relocate */

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bfd_byte r_index[3]; /* symbol table index of symbol */

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bfd_byte r_type[1]; /* relocation type */

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bfd_byte r_addend[BYTES_IN_WORD]; /* datum addend */

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};

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#define RELOC_EXT_BITS_EXTERN_BIG ((unsigned int) 0x80)

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#define RELOC_EXT_BITS_EXTERN_LITTLE ((unsigned int) 0x01)

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#define RELOC_EXT_BITS_TYPE_BIG ((unsigned int) 0x1F)

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#define RELOC_EXT_BITS_TYPE_SH_BIG 0

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#define RELOC_EXT_BITS_TYPE_LITTLE ((unsigned int) 0xF8)

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#define RELOC_EXT_BITS_TYPE_SH_LITTLE 3

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/* Bytes per relocation entry */

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#define RELOC_EXT_SIZE (BYTES_IN_WORD + 3 + 1 + BYTES_IN_WORD)

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enum reloc_type

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{

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/* simple relocations */

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RELOC_8, /* data[0:7] = addend + sv */

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RELOC_16, /* data[0:15] = addend + sv */

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RELOC_32, /* data[0:31] = addend + sv */

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/* pc-rel displacement */

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RELOC_DISP8, /* data[0:7] = addend - pc + sv */

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RELOC_DISP16, /* data[0:15] = addend - pc + sv */

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RELOC_DISP32, /* data[0:31] = addend - pc + sv */

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/* Special */

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RELOC_WDISP30, /* data[0:29] = (addend + sv - pc)>>2 */

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RELOC_WDISP22, /* data[0:21] = (addend + sv - pc)>>2 */

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RELOC_HI22, /* data[0:21] = (addend + sv)>>10 */

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RELOC_22, /* data[0:21] = (addend + sv) */

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RELOC_13, /* data[0:12] = (addend + sv) */

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RELOC_LO10, /* data[0:9] = (addend + sv) */

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RELOC_SFA_BASE,

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RELOC_SFA_OFF13,

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/* P.I.C. (base-relative) */

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RELOC_BASE10, /* Not sure - maybe we can do this the */

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RELOC_BASE13, /* right way now */

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RELOC_BASE22,

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/* for some sort of pc-rel P.I.C. (?) */

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RELOC_PC10,

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RELOC_PC22,

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/* P.I.C. jump table */

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RELOC_JMP_TBL,

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/* reputedly for shared libraries somehow */

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RELOC_SEGOFF16,

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RELOC_GLOB_DAT,

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RELOC_JMP_SLOT,

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RELOC_RELATIVE,

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RELOC_11,

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RELOC_WDISP2_14,

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RELOC_WDISP19,

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RELOC_HHI22, /* data[0:21] = (addend + sv) >> 42 */

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RELOC_HLO10, /* data[0:9] = (addend + sv) >> 32 */

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/* 29K relocation types */

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RELOC_JUMPTARG,

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RELOC_CONST,

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RELOC_CONSTH,

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/* All the new ones I can think of, for sparc v9 */

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RELOC_64, /* data[0:63] = addend + sv */

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RELOC_DISP64, /* data[0:63] = addend - pc + sv */

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RELOC_WDISP21, /* data[0:20] = (addend + sv - pc)>>2 */

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RELOC_DISP21, /* data[0:20] = addend - pc + sv */

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RELOC_DISP14, /* data[0:13] = addend - pc + sv */

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/* Q .

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What are the other ones,

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Since this is a clean slate, can we throw away the ones we dont

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understand ? Should we sort the values ? What about using a

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microcode format like the 68k ?

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*/

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NO_RELOC

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};

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struct reloc_internal {

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bfd_vma r_address; /* offset of of data to relocate */

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long r_index; /* symbol table index of symbol */

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enum reloc_type r_type; /* relocation type */

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bfd_vma r_addend; /* datum addend */

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};

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/* Q.

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Should the length of the string table be 4 bytes or 8 bytes ?

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Q.

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What about archive indexes ?

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*/

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#endif /* __A_OUT_64_H__ */