192 lines
7.6 KiB
C
192 lines
7.6 KiB
C
|
/* This file is a modified version of 'a.out.h'. It is to be used in all
|
||
|
|
GNU tools modified to support the i80960 (or tools that operate on
|
||
|
|
object files created by such tools).
|
||
|
|
|
||
|
|
Copyright 2001 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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
||
|
|
|
||
|
|
/* All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e.,
|
||
|
|
object code is generated on, and executed under the direction of a symbolic
|
||
|
|
debugger running on, a host system. We do not want to be subject to the
|
||
|
|
vagaries of which host it is or whether it supports COFF or a.out format,
|
||
|
|
or anything else. We DO want to:
|
||
|
|
|
||
|
|
o always generate the same format object files, regardless of host.
|
||
|
|
|
||
|
|
o have an 'a.out' header that we can modify for our own purposes
|
||
|
|
(the 80960 is typically an embedded processor and may require
|
||
|
|
enhanced linker support that the normal a.out.h header can't
|
||
|
|
accommodate).
|
||
|
|
|
||
|
|
As for byte-ordering, the following rules apply:
|
||
|
|
|
||
|
|
o Text and data that is actually downloaded to the target is always
|
||
|
|
in i80960 (little-endian) order.
|
||
|
|
|
||
|
|
o All other numbers (in the header, symbols, relocation directives)
|
||
|
|
are in host byte-order: object files CANNOT be lifted from a
|
||
|
|
little-end host and used on a big-endian (or vice versa) without
|
||
|
|
modification.
|
||
|
|
==> THIS IS NO LONGER TRUE USING BFD. WE CAN GENERATE ANY BYTE ORDER
|
||
|
|
FOR THE HEADER, AND READ ANY BYTE ORDER. PREFERENCE WOULD BE TO
|
||
|
|
USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST. <==
|
||
|
|
|
||
|
|
o The downloader ('comm960') takes care to generate a pseudo-header
|
||
|
|
with correct (i80960) byte-ordering before shipping text and data
|
||
|
|
off to the NINDY monitor in the target systems. Symbols and
|
||
|
|
relocation info are never sent to the target. */
|
||
|
|
|
||
|
|
#define BMAGIC 0415
|
||
|
|
/* We don't accept the following (see N_BADMAG macro).
|
||
|
|
They're just here so GNU code will compile. */
|
||
|
|
#define OMAGIC 0407 /* old impure format */
|
||
|
|
#define NMAGIC 0410 /* read-only text */
|
||
|
|
#define ZMAGIC 0413 /* demand load format */
|
||
|
|
|
||
|
|
/* FILE HEADER
|
||
|
|
All 'lengths' are given as a number of bytes.
|
||
|
|
All 'alignments' are for relinkable files only; an alignment of
|
||
|
|
'n' indicates the corresponding segment must begin at an
|
||
|
|
address that is a multiple of (2**n). */
|
||
|
|
struct external_exec
|
||
|
|
{
|
||
|
|
/* Standard stuff */
|
||
|
|
unsigned char e_info[4]; /* Identifies this as a b.out file */
|
||
|
|
unsigned char e_text[4]; /* Length of text */
|
||
|
|
unsigned char e_data[4]; /* Length of data */
|
||
|
|
unsigned char e_bss[4]; /* Length of uninitialized data area */
|
||
|
|
unsigned char e_syms[4]; /* Length of symbol table */
|
||
|
|
unsigned char e_entry[4]; /* Runtime start address */
|
||
|
|
unsigned char e_trsize[4]; /* Length of text relocation info */
|
||
|
|
unsigned char e_drsize[4]; /* Length of data relocation info */
|
||
|
|
|
||
|
|
/* Added for i960 */
|
||
|
|
unsigned char e_tload[4]; /* Text runtime load address */
|
||
|
|
unsigned char e_dload[4]; /* Data runtime load address */
|
||
|
|
unsigned char e_talign[1]; /* Alignment of text segment */
|
||
|
|
unsigned char e_dalign[1]; /* Alignment of data segment */
|
||
|
|
unsigned char e_balign[1]; /* Alignment of bss segment */
|
||
|
|
unsigned char e_relaxable[1];/* Assembled with enough info to allow linker to relax */
|
||
|
|
};
|
||
|
|
|
||
|
|
#define EXEC_BYTES_SIZE (sizeof (struct external_exec))
|
||
|
|
|
||
|
|
/* These macros use the a_xxx field names, since they operate on the exec
|
||
|
|
structure after it's been byte-swapped and realigned on the host machine. */
|
||
|
|
#define N_BADMAG(x) (((x).a_info)!=BMAGIC)
|
||
|
|
#define N_TXTOFF(x) EXEC_BYTES_SIZE
|
||
|
|
#define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text )
|
||
|
|
#define N_TROFF(x) ( N_DATOFF(x) + (x).a_data )
|
||
|
|
#define N_TRELOFF N_TROFF
|
||
|
|
#define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize )
|
||
|
|
#define N_DRELOFF N_DROFF
|
||
|
|
#define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize )
|
||
|
|
#define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms )
|
||
|
|
#define N_DATADDR(x) ( (x).a_dload )
|
||
|
|
|
||
|
|
/* Address of text segment in memory after it is loaded. */
|
||
|
|
#if !defined (N_TXTADDR)
|
||
|
|
#define N_TXTADDR(x) 0
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* A single entry in the symbol table. */
|
||
|
|
struct nlist
|
||
|
|
{
|
||
|
|
union
|
||
|
|
{
|
||
|
|
char* n_name;
|
||
|
|
struct nlist * n_next;
|
||
|
|
long n_strx; /* Index into string table */
|
||
|
|
} n_un;
|
||
|
|
|
||
|
|
unsigned char n_type; /* See below */
|
||
|
|
char n_other; /* Used in i80960 support -- see below */
|
||
|
|
short n_desc;
|
||
|
|
unsigned long n_value;
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
/* Legal values of n_type. */
|
||
|
|
#define N_UNDF 0 /* Undefined symbol */
|
||
|
|
#define N_ABS 2 /* Absolute symbol */
|
||
|
|
#define N_TEXT 4 /* Text symbol */
|
||
|
|
#define N_DATA 6 /* Data symbol */
|
||
|
|
#define N_BSS 8 /* BSS symbol */
|
||
|
|
#define N_FN 31 /* Filename symbol */
|
||
|
|
|
||
|
|
#define N_EXT 1 /* External symbol (OR'd in with one of above) */
|
||
|
|
#define N_TYPE 036 /* Mask for all the type bits */
|
||
|
|
#define N_STAB 0340 /* Mask for all bits used for SDB entries */
|
||
|
|
|
||
|
|
/* MEANING OF 'n_other'
|
||
|
|
|
||
|
|
If non-zero, the 'n_other' fields indicates either a leaf procedure or
|
||
|
|
a system procedure, as follows:
|
||
|
|
|
||
|
|
1 <= n_other <= 32 :
|
||
|
|
The symbol is the entry point to a system procedure.
|
||
|
|
'n_value' is the address of the entry, as for any other
|
||
|
|
procedure. The system procedure number (which can be used in
|
||
|
|
a 'calls' instruction) is (n_other-1). These entries come from
|
||
|
|
'.sysproc' directives.
|
||
|
|
|
||
|
|
n_other == N_CALLNAME
|
||
|
|
the symbol is the 'call' entry point to a leaf procedure.
|
||
|
|
The *next* symbol in the symbol table must be the corresponding
|
||
|
|
'bal' entry point to the procedure (see following). These
|
||
|
|
entries come from '.leafproc' directives in which two different
|
||
|
|
symbols are specified (the first one is represented here).
|
||
|
|
|
||
|
|
|
||
|
|
n_other == N_BALNAME
|
||
|
|
the symbol is the 'bal' entry point to a leaf procedure.
|
||
|
|
These entries result from '.leafproc' directives in which only
|
||
|
|
one symbol is specified, or in which the same symbol is
|
||
|
|
specified twice.
|
||
|
|
|
||
|
|
Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry,
|
||
|
|
but not every N_BALNAME entry must have an N_CALLNAME entry. */
|
||
|
|
#define N_CALLNAME ((char)-1)
|
||
|
|
#define N_BALNAME ((char)-2)
|
||
|
|
#define IS_CALLNAME(x) (N_CALLNAME == (x))
|
||
|
|
#define IS_BALNAME(x) (N_BALNAME == (x))
|
||
|
|
#define IS_OTHER(x) ((x)>0 && (x) <=32)
|
||
|
|
|
||
|
|
#define b_out_relocation_info relocation_info
|
||
|
|
struct relocation_info
|
||
|
|
{
|
||
|
|
int r_address; /* File address of item to be relocated. */
|
||
|
|
unsigned
|
||
|
|
#define r_index r_symbolnum
|
||
|
|
r_symbolnum:24, /* Index of symbol on which relocation is based,
|
||
|
|
if r_extern is set. Otherwise set to
|
||
|
|
either N_TEXT, N_DATA, or N_BSS to
|
||
|
|
indicate section on which relocation is
|
||
|
|
based. */
|
||
|
|
r_pcrel:1, /* 1 => relocate PC-relative; else absolute
|
||
|
|
On i960, pc-relative implies 24-bit
|
||
|
|
address, absolute implies 32-bit. */
|
||
|
|
r_length:2, /* Number of bytes to relocate:
|
||
|
|
0 => 1 byte
|
||
|
|
1 => 2 bytes -- used for 13 bit pcrel
|
||
|
|
2 => 4 bytes. */
|
||
|
|
r_extern:1,
|
||
|
|
r_bsr:1, /* Something for the GNU NS32K assembler. */
|
||
|
|
r_disp:1, /* Something for the GNU NS32K assembler. */
|
||
|
|
r_callj:1, /* 1 if relocation target is an i960 'callj'. */
|
||
|
|
r_relaxable:1; /* 1 if enough info is left to relax the data. */
|
||
|
|
};
|