ARCH

Section: C Library Functions (3)
Updated: July 19, 1993
Index Return to Main Contents
 

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

hppa   CPU_TYPE_HPPA     CPU_SUBTYPE_HPPA_ALL      HP-PA

i386   CPU_TYPE_I386     CPU_SUBTYPE_I386_ALL      Intel 80x86

i860   CPU_TYPE_I860     CPU_SUBTYPE_I860_ALL      Intel 860

m68k   CPU_TYPE_MC680x0  CPU_SUBTYPE_MC680x0_ALL   Motorola 68K

m88k   CPU_TYPE_MC88000  CPU_SUBTYPE_MC88000_ALL   Motorola 88K

m98k   CPU_TYPE_MC98000  CPU_SUBTYPE_MC98000_ALL   Power PC

mips   CPU_TYPE_MIPS     CPU_SUBTYPE_MIPS_ALL      MIPS

sparc  CPU_TYPE_SPARC    CPU_SUBTYPE_SUN4_ALL      SPARC

vax    CPU_TYPE_VAX      CPU_SUBTYPE_VAX_ALL       DEC VAX

i486   CPU_TYPE_I386     CPU_SUBTYPE_486           Intel 486

i486SX CPU_TYPE_I386     CPU_SUBTYPE_486SX         Intel 486SX

i586   CPU_TYPE_I386     CPU_SUBTYPE_586           Intel 586

i586SX CPU_TYPE_I386     CPU_SUBTYPE_586SX         Intel 586SX

m68030 CPU_TYPE_MC680x0  CPU_SUBTYPE_MC68030_ONLY  Motorola 68030

m68040 CPU_TYPE_MC680x0  CPU_SUBTYPE_MC68040       Motorola 68040

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.


 

Index

NAME
SYNOPSIS
DESCRIPTION

This document was created by man2html, using the manual pages.
Time: 17:20:31 GMT, March 25, 2025