ARCH(3)

NAME
NXGetAllArchInfos, NXGetLocalArchInfo, NXGetArchInfoFromName, NXGetArchInfoFromCpuType, NXFindBestFatArch, NXCombineCpuSubtypes - get architecture 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. Typically, 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> as follows:
	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
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
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 combination. 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_arch 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 subtypes are the same, they can always be combined and this routine will return the CPU subtype passed in.