GNU tools modified to support the i80960 (or tools that operate on
object files created by such tools).
Copyright 2001, 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. */
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
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 */
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
{
unsigned char e_info[4];
unsigned char e_text[4];
unsigned char e_data[4];
unsigned char e_bss[4];
unsigned char e_syms[4];
unsigned char e_entry[4];
unsigned char e_trsize[4];
unsigned char e_drsize[4];
unsigned char e_tload[4];
unsigned char e_dload[4];
unsigned char e_talign[1];
unsigned char e_dalign[1];
unsigned char e_balign[1];
unsigned char e_relaxable[1];
};
#define EXEC_BYTES_SIZE (sizeof (struct external_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 )
#if !defined (N_TXTADDR)
#define N_TXTADDR(x) 0
#endif
struct nlist
{
union
{
char* n_name;
struct nlist * n_next;
long n_strx;
} n_un;
unsigned char n_type;
char n_other;
short n_desc;
unsigned long n_value;
};
#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 */
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;
unsigned
#define r_index r_symbolnum
r_symbolnum:24,
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,
On i960, pc-relative implies 24-bit
address, absolute implies 32-bit. */
r_length:2,
0 => 1 byte
1 => 2 bytes -- used for 13 bit pcrel
2 => 4 bytes. */
r_extern:1,
r_bsr:1,
r_disp:1,
r_callj:1,
r_relaxable:1;
};
