bfd/doc/archures.texi

@section Architectures
BFD keeps one atom in a BFD describing the
architecture of the data attached to the BFD: a pointer to a
@code{bfd_arch_info_type}.

Pointers to structures can be requested independently of a BFD
so that an architecture's information can be interrogated
without access to an open BFD.

The architecture information is provided by each architecture package.
The set of default architectures is selected by the macro
@code{SELECT_ARCHITECTURES}.  This is normally set up in the
@file{config/@var{target}.mt} file of your choice.  If the name is not
defined, then all the architectures supported are included.

When BFD starts up, all the architectures are called with an
initialize method.  It is up to the architecture back end to
insert as many items into the list of architectures as it wants to;
generally this would be one for each machine and one for the
default case (an item with a machine field of 0).

BFD's idea of an architecture is implemented in @file{archures.c}.

@subsection bfd_architecture


@strong{Description}@*
This enum gives the object file's CPU architecture, in a
global sense---i.e., what processor family does it belong to?
Another field indicates which processor within
the family is in use.  The machine gives a number which
distinguishes different versions of the architecture,
containing, for example, 2 and 3 for Intel i960 KA and i960 KB,
and 68020 and 68030 for Motorola 68020 and 68030.
@example
enum bfd_architecture
@{
  bfd_arch_unknown,   /* File arch not known.  */
  bfd_arch_obscure,   /* Arch known, not one of these.  */
  bfd_arch_m68k,      /* Motorola 68xxx */
#define bfd_mach_m68000 1
#define bfd_mach_m68008 2
#define bfd_mach_m68010 3
#define bfd_mach_m68020 4
#define bfd_mach_m68030 5
#define bfd_mach_m68040 6
#define bfd_mach_m68060 7
#define bfd_mach_cpu32  8
#define bfd_mach_fido   9
#define bfd_mach_mcf_isa_a_nodiv 10
#define bfd_mach_mcf_isa_a 11
#define bfd_mach_mcf_isa_a_mac 12
#define bfd_mach_mcf_isa_a_emac 13
#define bfd_mach_mcf_isa_aplus 14
#define bfd_mach_mcf_isa_aplus_mac 15
#define bfd_mach_mcf_isa_aplus_emac 16
#define bfd_mach_mcf_isa_b_nousp 17
#define bfd_mach_mcf_isa_b_nousp_mac 18
#define bfd_mach_mcf_isa_b_nousp_emac 19
#define bfd_mach_mcf_isa_b 20
#define bfd_mach_mcf_isa_b_mac 21
#define bfd_mach_mcf_isa_b_emac 22
#define bfd_mach_mcf_isa_b_float 23
#define bfd_mach_mcf_isa_b_float_mac 24
#define bfd_mach_mcf_isa_b_float_emac 25
#define bfd_mach_mcf_isa_c 26
#define bfd_mach_mcf_isa_c_mac 27
#define bfd_mach_mcf_isa_c_emac 28
#define bfd_mach_mcf_isa_c_nodiv 29
#define bfd_mach_mcf_isa_c_nodiv_mac 30
#define bfd_mach_mcf_isa_c_nodiv_emac 31
  bfd_arch_vax,       /* DEC Vax */
  bfd_arch_i960,      /* Intel 960 */
    /* The order of the following is important.
       lower number indicates a machine type that
       only accepts a subset of the instructions
       available to machines with higher numbers.
       The exception is the "ca", which is
       incompatible with all other machines except
       "core".  */

#define bfd_mach_i960_core      1
#define bfd_mach_i960_ka_sa     2
#define bfd_mach_i960_kb_sb     3
#define bfd_mach_i960_mc        4
#define bfd_mach_i960_xa        5
#define bfd_mach_i960_ca        6
#define bfd_mach_i960_jx        7
#define bfd_mach_i960_hx        8

  bfd_arch_or32,      /* OpenRISC 32 */

  bfd_arch_sparc,     /* SPARC */
#define bfd_mach_sparc                 1
/* The difference between v8plus and v9 is that v9 is a true 64 bit env.  */
#define bfd_mach_sparc_sparclet        2
#define bfd_mach_sparc_sparclite       3
#define bfd_mach_sparc_v8plus          4
#define bfd_mach_sparc_v8plusa         5 /* with ultrasparc add'ns.  */
#define bfd_mach_sparc_sparclite_le    6
#define bfd_mach_sparc_v9              7
#define bfd_mach_sparc_v9a             8 /* with ultrasparc add'ns.  */
#define bfd_mach_sparc_v8plusb         9 /* with cheetah add'ns.  */
#define bfd_mach_sparc_v9b             10 /* with cheetah add'ns.  */
/* Nonzero if MACH has the v9 instruction set.  */
#define bfd_mach_sparc_v9_p(mach) \
  ((mach) >= bfd_mach_sparc_v8plus && (mach) <= bfd_mach_sparc_v9b \
   && (mach) != bfd_mach_sparc_sparclite_le)
/* Nonzero if MACH is a 64 bit sparc architecture.  */
#define bfd_mach_sparc_64bit_p(mach) \
  ((mach) >= bfd_mach_sparc_v9 && (mach) != bfd_mach_sparc_v8plusb)
  bfd_arch_spu,       /* PowerPC SPU */
#define bfd_mach_spu           256
  bfd_arch_mips,      /* MIPS Rxxxx */
#define bfd_mach_mips3000              3000
#define bfd_mach_mips3900              3900
#define bfd_mach_mips4000              4000
#define bfd_mach_mips4010              4010
#define bfd_mach_mips4100              4100
#define bfd_mach_mips4111              4111
#define bfd_mach_mips4120              4120
#define bfd_mach_mips4300              4300
#define bfd_mach_mips4400              4400
#define bfd_mach_mips4600              4600
#define bfd_mach_mips4650              4650
#define bfd_mach_mips5000              5000
#define bfd_mach_mips5400              5400
#define bfd_mach_mips5500              5500
#define bfd_mach_mips6000              6000
#define bfd_mach_mips7000              7000
#define bfd_mach_mips8000              8000
#define bfd_mach_mips9000              9000
#define bfd_mach_mips10000             10000
#define bfd_mach_mips12000             12000
#define bfd_mach_mips16                16
#define bfd_mach_mips5                 5
#define bfd_mach_mips_loongson_2e      3001
#define bfd_mach_mips_loongson_2f      3002
#define bfd_mach_mips_sb1              12310201 /* octal 'SB', 01 */
#define bfd_mach_mips_octeon           6501
#define bfd_mach_mipsisa32             32
#define bfd_mach_mipsisa32r2           33
#define bfd_mach_mipsisa64             64
#define bfd_mach_mipsisa64r2           65
  bfd_arch_i386,      /* Intel 386 */
#define bfd_mach_i386_i386 1
#define bfd_mach_i386_i8086 2
#define bfd_mach_i386_i386_intel_syntax 3
#define bfd_mach_x86_64 64
#define bfd_mach_x86_64_intel_syntax 65
  bfd_arch_we32k,     /* AT&T WE32xxx */
  bfd_arch_tahoe,     /* CCI/Harris Tahoe */
  bfd_arch_i860,      /* Intel 860 */
  bfd_arch_i370,      /* IBM 360/370 Mainframes */
  bfd_arch_romp,      /* IBM ROMP PC/RT */
  bfd_arch_convex,    /* Convex */
  bfd_arch_m88k,      /* Motorola 88xxx */
  bfd_arch_m98k,      /* Motorola 98xxx */
  bfd_arch_pyramid,   /* Pyramid Technology */
  bfd_arch_h8300,     /* Renesas H8/300 (formerly Hitachi H8/300) */
#define bfd_mach_h8300    1
#define bfd_mach_h8300h   2
#define bfd_mach_h8300s   3
#define bfd_mach_h8300hn  4
#define bfd_mach_h8300sn  5
#define bfd_mach_h8300sx  6
#define bfd_mach_h8300sxn 7
  bfd_arch_pdp11,     /* DEC PDP-11 */
  bfd_arch_powerpc,   /* PowerPC */
#define bfd_mach_ppc           32
#define bfd_mach_ppc64         64
#define bfd_mach_ppc_403       403
#define bfd_mach_ppc_403gc     4030
#define bfd_mach_ppc_505       505
#define bfd_mach_ppc_601       601
#define bfd_mach_ppc_602       602
#define bfd_mach_ppc_603       603
#define bfd_mach_ppc_ec603e    6031
#define bfd_mach_ppc_604       604
#define bfd_mach_ppc_620       620
#define bfd_mach_ppc_630       630
#define bfd_mach_ppc_750       750
#define bfd_mach_ppc_860       860
#define bfd_mach_ppc_a35       35
#define bfd_mach_ppc_rs64ii    642
#define bfd_mach_ppc_rs64iii   643
#define bfd_mach_ppc_7400      7400
#define bfd_mach_ppc_e500      500
#define bfd_mach_ppc_e500mc    5001
  bfd_arch_rs6000,    /* IBM RS/6000 */
#define bfd_mach_rs6k          6000
#define bfd_mach_rs6k_rs1      6001
#define bfd_mach_rs6k_rsc      6003
#define bfd_mach_rs6k_rs2      6002
  bfd_arch_hppa,      /* HP PA RISC */
#define bfd_mach_hppa10        10
#define bfd_mach_hppa11        11
#define bfd_mach_hppa20        20
#define bfd_mach_hppa20w       25
  bfd_arch_d10v,      /* Mitsubishi D10V */
#define bfd_mach_d10v          1
#define bfd_mach_d10v_ts2      2
#define bfd_mach_d10v_ts3      3
  bfd_arch_d30v,      /* Mitsubishi D30V */
  bfd_arch_dlx,       /* DLX */
  bfd_arch_m68hc11,   /* Motorola 68HC11 */
  bfd_arch_m68hc12,   /* Motorola 68HC12 */
#define bfd_mach_m6812_default 0
#define bfd_mach_m6812         1
#define bfd_mach_m6812s        2
  bfd_arch_z8k,       /* Zilog Z8000 */
#define bfd_mach_z8001         1
#define bfd_mach_z8002         2
  bfd_arch_h8500,     /* Renesas H8/500 (formerly Hitachi H8/500) */
  bfd_arch_sh,        /* Renesas / SuperH SH (formerly Hitachi SH) */
#define bfd_mach_sh            1
#define bfd_mach_sh2        0x20
#define bfd_mach_sh_dsp     0x2d
#define bfd_mach_sh2a       0x2a
#define bfd_mach_sh2a_nofpu 0x2b
#define bfd_mach_sh2a_nofpu_or_sh4_nommu_nofpu 0x2a1
#define bfd_mach_sh2a_nofpu_or_sh3_nommu 0x2a2
#define bfd_mach_sh2a_or_sh4  0x2a3
#define bfd_mach_sh2a_or_sh3e 0x2a4
#define bfd_mach_sh2e       0x2e
#define bfd_mach_sh3        0x30
#define bfd_mach_sh3_nommu  0x31
#define bfd_mach_sh3_dsp    0x3d
#define bfd_mach_sh3e       0x3e
#define bfd_mach_sh4        0x40
#define bfd_mach_sh4_nofpu  0x41
#define bfd_mach_sh4_nommu_nofpu  0x42
#define bfd_mach_sh4a       0x4a
#define bfd_mach_sh4a_nofpu 0x4b
#define bfd_mach_sh4al_dsp  0x4d
#define bfd_mach_sh5        0x50
  bfd_arch_alpha,     /* Dec Alpha */
#define bfd_mach_alpha_ev4  0x10
#define bfd_mach_alpha_ev5  0x20
#define bfd_mach_alpha_ev6  0x30
  bfd_arch_arm,       /* Advanced Risc Machines ARM.  */
#define bfd_mach_arm_unknown   0
#define bfd_mach_arm_2         1
#define bfd_mach_arm_2a        2
#define bfd_mach_arm_3         3
#define bfd_mach_arm_3M        4
#define bfd_mach_arm_4         5
#define bfd_mach_arm_4T        6
#define bfd_mach_arm_5         7
#define bfd_mach_arm_5T        8
#define bfd_mach_arm_5TE       9
#define bfd_mach_arm_XScale    10
#define bfd_mach_arm_ep9312    11
#define bfd_mach_arm_iWMMXt    12
#define bfd_mach_arm_iWMMXt2   13
  bfd_arch_ns32k,     /* National Semiconductors ns32000 */
  bfd_arch_w65,       /* WDC 65816 */
  bfd_arch_tic30,     /* Texas Instruments TMS320C30 */
  bfd_arch_tic4x,     /* Texas Instruments TMS320C3X/4X */
#define bfd_mach_tic3x         30
#define bfd_mach_tic4x         40
  bfd_arch_tic54x,    /* Texas Instruments TMS320C54X */
  bfd_arch_tic80,     /* TI TMS320c80 (MVP) */
  bfd_arch_v850,      /* NEC V850 */
#define bfd_mach_v850          1
#define bfd_mach_v850e         'E'
#define bfd_mach_v850e1        '1'
  bfd_arch_arc,       /* ARC Cores */
#define bfd_mach_arc_5         5
#define bfd_mach_arc_6         6
#define bfd_mach_arc_7         7
#define bfd_mach_arc_8         8
 bfd_arch_m32c,     /* Renesas M16C/M32C.  */
#define bfd_mach_m16c        0x75
#define bfd_mach_m32c        0x78
  bfd_arch_m32r,      /* Renesas M32R (formerly Mitsubishi M32R/D) */
#define bfd_mach_m32r          1 /* For backwards compatibility.  */
#define bfd_mach_m32rx         'x'
#define bfd_mach_m32r2         '2'
  bfd_arch_mn10200,   /* Matsushita MN10200 */
  bfd_arch_mn10300,   /* Matsushita MN10300 */
#define bfd_mach_mn10300               300
#define bfd_mach_am33          330
#define bfd_mach_am33_2        332
  bfd_arch_fr30,
#define bfd_mach_fr30          0x46523330
  bfd_arch_frv,
#define bfd_mach_frv           1
#define bfd_mach_frvsimple     2
#define bfd_mach_fr300         300
#define bfd_mach_fr400         400
#define bfd_mach_fr450         450
#define bfd_mach_frvtomcat     499     /* fr500 prototype */
#define bfd_mach_fr500         500
#define bfd_mach_fr550         550
  bfd_arch_mcore,
  bfd_arch_mep,
#define bfd_mach_mep           1
#define bfd_mach_mep_h1        0x6831
  bfd_arch_ia64,      /* HP/Intel ia64 */
#define bfd_mach_ia64_elf64    64
#define bfd_mach_ia64_elf32    32
  bfd_arch_ip2k,      /* Ubicom IP2K microcontrollers. */
#define bfd_mach_ip2022        1
#define bfd_mach_ip2022ext     2
 bfd_arch_iq2000,     /* Vitesse IQ2000.  */
#define bfd_mach_iq2000        1
#define bfd_mach_iq10          2
  bfd_arch_mt,
#define bfd_mach_ms1           1
#define bfd_mach_mrisc2        2
#define bfd_mach_ms2           3
  bfd_arch_pj,
  bfd_arch_avr,       /* Atmel AVR microcontrollers.  */
#define bfd_mach_avr1          1
#define bfd_mach_avr2          2
#define bfd_mach_avr25         25
#define bfd_mach_avr3          3
#define bfd_mach_avr31         31
#define bfd_mach_avr35         35
#define bfd_mach_avr4          4
#define bfd_mach_avr5          5
#define bfd_mach_avr51         51
#define bfd_mach_avr6          6
  bfd_arch_bfin,        /* ADI Blackfin */
#define bfd_mach_bfin          1
  bfd_arch_cr16,       /* National Semiconductor CompactRISC (ie CR16). */
#define bfd_mach_cr16          1
  bfd_arch_cr16c,       /* National Semiconductor CompactRISC. */
#define bfd_mach_cr16c         1
  bfd_arch_crx,       /*  National Semiconductor CRX.  */
#define bfd_mach_crx           1
  bfd_arch_cris,      /* Axis CRIS */
#define bfd_mach_cris_v0_v10   255
#define bfd_mach_cris_v32      32
#define bfd_mach_cris_v10_v32  1032
  bfd_arch_s390,      /* IBM s390 */
#define bfd_mach_s390_31       31
#define bfd_mach_s390_64       64
  bfd_arch_score,     /* Sunplus score */
  bfd_arch_openrisc,  /* OpenRISC */
  bfd_arch_mmix,      /* Donald Knuth's educational processor.  */
  bfd_arch_xstormy16,
#define bfd_mach_xstormy16     1
  bfd_arch_msp430,    /* Texas Instruments MSP430 architecture.  */
#define bfd_mach_msp11          11
#define bfd_mach_msp110         110
#define bfd_mach_msp12          12
#define bfd_mach_msp13          13
#define bfd_mach_msp14          14
#define bfd_mach_msp15          15
#define bfd_mach_msp16          16
#define bfd_mach_msp21          21
#define bfd_mach_msp31          31
#define bfd_mach_msp32          32
#define bfd_mach_msp33          33
#define bfd_mach_msp41          41
#define bfd_mach_msp42          42
#define bfd_mach_msp43          43
#define bfd_mach_msp44          44
  bfd_arch_xc16x,     /* Infineon's XC16X Series.               */
#define bfd_mach_xc16x         1
#define bfd_mach_xc16xl        2
#define bfd_mach_xc16xs         3
  bfd_arch_xtensa,    /* Tensilica's Xtensa cores.  */
#define bfd_mach_xtensa        1
   bfd_arch_maxq,     /* Dallas MAXQ 10/20 */
#define bfd_mach_maxq10    10
#define bfd_mach_maxq20    20
  bfd_arch_z80,
#define bfd_mach_z80strict      1 /* No undocumented opcodes.  */
#define bfd_mach_z80            3 /* With ixl, ixh, iyl, and iyh.  */
#define bfd_mach_z80full        7 /* All undocumented instructions.  */
#define bfd_mach_r800           11 /* R800: successor with multiplication.  */
  bfd_arch_last
  @};
@end example

@subsection bfd_arch_info


@strong{Description}@*
This structure contains information on architectures for use
within BFD.
@example

typedef struct bfd_arch_info
@{
  int bits_per_word;
  int bits_per_address;
  int bits_per_byte;
  enum bfd_architecture arch;
  unsigned long mach;
  const char *arch_name;
  const char *printable_name;
  unsigned int section_align_power;
  /* TRUE if this is the default machine for the architecture.
     The default arch should be the first entry for an arch so that
     all the entries for that arch can be accessed via @code{next}.  */
  bfd_boolean the_default;
  const struct bfd_arch_info * (*compatible)
    (const struct bfd_arch_info *a, const struct bfd_arch_info *b);

  bfd_boolean (*scan) (const struct bfd_arch_info *, const char *);

  const struct bfd_arch_info *next;
@}
bfd_arch_info_type;

@end example

@findex bfd_printable_name
@subsubsection @code{bfd_printable_name}
@strong{Synopsis}
@example
const char *bfd_printable_name (bfd *abfd);
@end example
@strong{Description}@*
Return a printable string representing the architecture and machine
from the pointer to the architecture info structure.

@findex bfd_scan_arch
@subsubsection @code{bfd_scan_arch}
@strong{Synopsis}
@example
const bfd_arch_info_type *bfd_scan_arch (const char *string);
@end example
@strong{Description}@*
Figure out if BFD supports any cpu which could be described with
the name @var{string}.  Return a pointer to an @code{arch_info}
structure if a machine is found, otherwise NULL.

@findex bfd_arch_list
@subsubsection @code{bfd_arch_list}
@strong{Synopsis}
@example
const char **bfd_arch_list (void);
@end example
@strong{Description}@*
Return a freshly malloced NULL-terminated vector of the names
of all the valid BFD architectures.  Do not modify the names.

@findex bfd_arch_get_compatible
@subsubsection @code{bfd_arch_get_compatible}
@strong{Synopsis}
@example
const bfd_arch_info_type *bfd_arch_get_compatible
   (const bfd *abfd, const bfd *bbfd, bfd_boolean accept_unknowns);
@end example
@strong{Description}@*
Determine whether two BFDs' architectures and machine types
are compatible.  Calculates the lowest common denominator
between the two architectures and machine types implied by
the BFDs and returns a pointer to an @code{arch_info} structure
describing the compatible machine.

@findex bfd_default_arch_struct
@subsubsection @code{bfd_default_arch_struct}
@strong{Description}@*
The @code{bfd_default_arch_struct} is an item of
@code{bfd_arch_info_type} which has been initialized to a fairly
generic state.  A BFD starts life by pointing to this
structure, until the correct back end has determined the real
architecture of the file.
@example
extern const bfd_arch_info_type bfd_default_arch_struct;
@end example

@findex bfd_set_arch_info
@subsubsection @code{bfd_set_arch_info}
@strong{Synopsis}
@example
void bfd_set_arch_info (bfd *abfd, const bfd_arch_info_type *arg);
@end example
@strong{Description}@*
Set the architecture info of @var{abfd} to @var{arg}.

@findex bfd_default_set_arch_mach
@subsubsection @code{bfd_default_set_arch_mach}
@strong{Synopsis}
@example
bfd_boolean bfd_default_set_arch_mach
   (bfd *abfd, enum bfd_architecture arch, unsigned long mach);
@end example
@strong{Description}@*
Set the architecture and machine type in BFD @var{abfd}
to @var{arch} and @var{mach}.  Find the correct
pointer to a structure and insert it into the @code{arch_info}
pointer.

@findex bfd_get_arch
@subsubsection @code{bfd_get_arch}
@strong{Synopsis}
@example
enum bfd_architecture bfd_get_arch (bfd *abfd);
@end example
@strong{Description}@*
Return the enumerated type which describes the BFD @var{abfd}'s
architecture.

@findex bfd_get_mach
@subsubsection @code{bfd_get_mach}
@strong{Synopsis}
@example
unsigned long bfd_get_mach (bfd *abfd);
@end example
@strong{Description}@*
Return the long type which describes the BFD @var{abfd}'s
machine.

@findex bfd_arch_bits_per_byte
@subsubsection @code{bfd_arch_bits_per_byte}
@strong{Synopsis}
@example
unsigned int bfd_arch_bits_per_byte (bfd *abfd);
@end example
@strong{Description}@*
Return the number of bits in one of the BFD @var{abfd}'s
architecture's bytes.

@findex bfd_arch_bits_per_address
@subsubsection @code{bfd_arch_bits_per_address}
@strong{Synopsis}
@example
unsigned int bfd_arch_bits_per_address (bfd *abfd);
@end example
@strong{Description}@*
Return the number of bits in one of the BFD @var{abfd}'s
architecture's addresses.

@findex bfd_default_compatible
@subsubsection @code{bfd_default_compatible}
@strong{Synopsis}
@example
const bfd_arch_info_type *bfd_default_compatible
   (const bfd_arch_info_type *a, const bfd_arch_info_type *b);
@end example
@strong{Description}@*
The default function for testing for compatibility.

@findex bfd_default_scan
@subsubsection @code{bfd_default_scan}
@strong{Synopsis}
@example
bfd_boolean bfd_default_scan
   (const struct bfd_arch_info *info, const char *string);
@end example
@strong{Description}@*
The default function for working out whether this is an
architecture hit and a machine hit.

@findex bfd_get_arch_info
@subsubsection @code{bfd_get_arch_info}
@strong{Synopsis}
@example
const bfd_arch_info_type *bfd_get_arch_info (bfd *abfd);
@end example
@strong{Description}@*
Return the architecture info struct in @var{abfd}.

@findex bfd_lookup_arch
@subsubsection @code{bfd_lookup_arch}
@strong{Synopsis}
@example
const bfd_arch_info_type *bfd_lookup_arch
   (enum bfd_architecture arch, unsigned long machine);
@end example
@strong{Description}@*
Look for the architecture info structure which matches the
arguments @var{arch} and @var{machine}. A machine of 0 matches the
machine/architecture structure which marks itself as the
default.

@findex bfd_printable_arch_mach
@subsubsection @code{bfd_printable_arch_mach}
@strong{Synopsis}
@example
const char *bfd_printable_arch_mach
   (enum bfd_architecture arch, unsigned long machine);
@end example
@strong{Description}@*
Return a printable string representing the architecture and
machine type.

This routine is depreciated.

@findex bfd_octets_per_byte
@subsubsection @code{bfd_octets_per_byte}
@strong{Synopsis}
@example
unsigned int bfd_octets_per_byte (bfd *abfd);
@end example
@strong{Description}@*
Return the number of octets (8-bit quantities) per target byte
(minimum addressable unit).  In most cases, this will be one, but some
DSP targets have 16, 32, or even 48 bits per byte.

@findex bfd_arch_mach_octets_per_byte
@subsubsection @code{bfd_arch_mach_octets_per_byte}
@strong{Synopsis}
@example
unsigned int bfd_arch_mach_octets_per_byte
   (enum bfd_architecture arch, unsigned long machine);
@end example
@strong{Description}@*
See bfd_octets_per_byte.

This routine is provided for those cases where a bfd * is not
available