ARCH(3) 						   BSD Library Functions Manual 						   ARCH(3)

NAME

     NXGetAllArchInfos, NXGetLocalArchInfo, NXGetArchInfoFromName, NXGetArchInfoFromCpuType, NXFindBestFatArch, NXCombineCpuSubtypes -- get archi-
     tecture information

SYNOPSIS

     #include <mach-o/arch.h>

     extern const NXArchInfo *
     NXGetAllArchInfos(void);

     extern const NXArchInfo *
     NXGetLocalArchInfo(void);

     extern const NXArchInfo *
     NXGetArchInfoFromName(const char *name);

     extern const NXArchInfo *
     NXGetArchInfoFromCpuType(cpu_type_t cputype, cpu_subtype_t cpusubtype);

     extern struct fat_arch *
     NXFindBestFatArch(cpu_type_t cputype, cpu_subtype_t cpusubtype, struct fat_arch *fat_archs, unsigned long nfat_archs);

     extern cpu_subtype_t
     NXCombineCpuSubtypes(cpu_type_t cputype, cpu_subtype_t cpusubtype1, cpu_subtype_t cpusubtype2);

DESCRIPTION

     These functions are intended for use in programs that have to deal with fat files or programs that can target multiple architectures.  Typi-
     cally, a program will use a command-line argument that starts with ``-arch name'', where this specifies an architecture.  These functions and
     data structures provide some help for processing architecture flags and then processing the contents of a fat file.

     The structure NXArchInfo is defined in <mach-o/arch.h>:

		   typedef struct {
			   const char *name;
			   cpu_type_t cputype;
			   cpu_subtype_t cpusubtype;
			   enum NXByteOrder byteorder;
			   const char *description;
		   } NXArchInfo;
     It is used to hold the name of the architecture and the corresponding CPU type and CPU subtype, together with the architecture's byte order
     and a brief description string.

     The currently known architectures are:

     Name	   CPU Type	       CPU Subtype		   Description
     ppc	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_ALL	   PowerPC
     i386	   CPU_TYPE_I386       CPU_SUBTYPE_I386_ALL	   Intel 80x86
     m68k	   CPU_TYPE_MC680x0    CPU_SUBTYPE_MC680x0_ALL	   Motorola 68K
     hppa	   CPU_TYPE_HPPA       CPU_SUBTYPE_HPPA_ALL	   HP-PA
     i860	   CPU_TYPE_I860       CPU_SUBTYPE_I860_ALL	   Intel 860
     m88k	   CPU_TYPE_MC88000    CPU_SUBTYPE_MC88000_ALL	   Motorola 88K
     sparc	   CPU_TYPE_SPARC      CPU_SUBTYPE_SPARC_ALL	   SPARC
     ppc601	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_601	   PowerPC 601
     ppc603	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_603	   PowerPC 603
     ppc604	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_604	   PowerPC 604
     ppc604e	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_604e    PowerPC 604e
     ppc750	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_750	   PowerPC 750
     ppc7400	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_7400    PowerPC 7400
     ppc7450	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_7450    PowerPC 7450
     ppc970	   CPU_TYPE_POWERPC    CPU_SUBTYPE_POWERPC_970	   PowerPC 970
     i486	   CPU_TYPE_I386       CPU_SUBTYPE_486		   Intel 486
     i486SX	   CPU_TYPE_I386       CPU_SUBTYPE_486SX	   Intel 486SX
     pentium	   CPU_TYPE_I386       CPU_SUBTYPE_PENT 	   Intel Pentium
     i586	   CPU_TYPE_I386       CPU_SUBTYPE_586		   Intel 586
     pentpro	   CPU_TYPE_I386       CPU_SUBTYPE_PENTPRO	   Intel Pentium Pro
     i686	   CPU_TYPE_I386       CPU_SUBTYPE_PENTPRO	   Intel Pentium Pro
     pentIIm3	   CPU_TYPE_I386       CPU_SUBTYPE_PENTII_M3	   Intel Pentium II Model 3
     pentIIm5	   CPU_TYPE_I386       CPU_SUBTYPE_PENTII_M5	   Intel Pentium II Model 5
     m68030	   CPU_TYPE_MC680x0    CPU_SUBTYPE_MC68030_ONLY    Motorola 68030
     m68040	   CPU_TYPE_MC680x0    CPU_SUBTYPE_MC68040	   Motorola 68040
     hppa7100LC    CPU_TYPE_HPPA       CPU_SUBTYPE_HPPA_7100LC	   HP-PA 7100LC

     The first set of entries are used for the architecture family.  The second set of entries are used for a specific architecture, when more
     than one specific architecture is supported in a family of architectures.

     NXGetAllArchInfos() returns a pointer to an array of all known NXArchInfo structures.  The last NXArchInfo is marked by a NULL name.

     NXGetLocalArchInfo() returns the NXArchInfo for the local host, or NULL if none is known.

     NXGetArchInfoFromName() and NXGetArchInfoFromCpuType() return the NXArchInfo from the architecture's name or CPU type/CPU subtype combina-
     tion.  A CPU subtype of CPU_SUBTYPE_MULTIPLE can be used to request the most general NXArchInfo known for the given CPU type.  NULL is
     returned if no matching NXArchInfo can be found.

     NXFindBestFatArch() is passed a CPU type and CPU subtype and a set of fat_arch structs.  It selects the best one that matches (if any), and
     returns a pointer to that fat_arch struct (or NULL).  The fat_arch structs must be in the host byte order and correct such that fat_archs
     really points to enough memory for nfat_archs structs.  It is possible that this routine could fail if new CPU types or CPU subtypes are
     added and an old version of this routine is used.	But if there is an exact match between the CPU type and CPU subtype and one of the
     fat_arch structs, this routine will always succeed.

     NXCombineCpuSubtypes() returns the resulting CPU subtype when combining two different CPU subtypes for the specified CPU type.  If the two
     CPU subtypes can't be combined (the specific subtypes are mutually exclusive), -1 is returned, indicating it is an error to combine them.
     This can also fail and return -1 if new CPU types or CPU subtypes are added and an old version of this routine is used.  But if the CPU sub-
     types are the same, they can always be combined and this routine will return the CPU subtype passed in.

SEE ALSO

     arch(1)

								   May 21, 2003