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getaddressconf(2)
NAME
  getaddressconf - Gets information about system address space configuration

SYNOPSIS
  #include <sys/types.h>
  #include <sys/addrconf.h>
  int getaddressconf (
	  struct addressconf *buffer,
	  size_t length );

PARAMETERS
  buffer    Points to an array of addressconf structures.

  length    Specifies the size in bytes of the array pointed to by the buffer
	    parameter.

DESCRIPTION
  The getaddressconf() function fills in the array of structures pointed to
  by the buffer parameter with information describing the configuration of
  process address spaces on this system.  This information is intended to be
  used by programs such as the program loader, which need to manage the
  contents of a process' address space using the memory management primitives
  such as the mmap() function.

  The buffer parameter points to an array of addressconf structures,
  occupying a total of length bytes.  Each element of the array describes a
  single area of the process address space.  The addressconf structure is
  defined in the sys/addrconf.h header file, and it contains the following
  members:
       caddr_t ac_base;
       unsigned ac_flags;

  ac_bas    The base virtual address of the area.  For an upward-growing
	    area, this is the lowest virtual address in the area; for a
	    downward-growing area, this is the lowest virtual address above
	    the area.

  ac_flags  The flags describe the area.  They are also defined in the
	    sys/addrconf.h header file, and are described as follows:

	    AC_UPWARD The area grows towards higher addresses.	The base
		      address specified is the lowest address in the area.

	    AC_DOWNWARD
		      The area grows towards lower addresses.  The base
		      address specified is the lowest address above the area.

	    AC_FIXED  The area always starts at the specified base address.
		      For example, on many machines the text area is a fixed
		      area.

	    AC_FLOAT  The area floats to the first available virtual address
		      above the specified base address.	 For example, on many
		      machines, the data area floats above the text area.

  Each element in the array of addressconf structures describes a separate
  area of the process' address space.  These areas have been defined in the
  sys/addrconf.h header file; other areas may be defined in the future or on
  other machine types.	The array elements are indexed with the following
  constants:

  AC_TEXT   The area that normally contains the text region of an absolute
	    executable program.

  AC_DATA   The area that normally contains the data region of an absolute
	    executable program.

  AC_BSS    The area that normally contains the bss region of an absolute
	    executable program.

  AC_STACK  The area that normally contains the process' user-mode stack.

  AC_LDR_TEXT
	    The area reserved for the text region of the default program
	    loader see the exec_with_loader() function.

  AC_LDR_DATA
	    The area reserved for the data region of the default program
	    loader.

  AC_LDR_BSS
	    The area reserved for the bss region of the default program
	    loader.

  AC_MMAP_TEXT
	    The area that normally contains text regions of relocatable files
	    loaded by the program loader, or otherwise mapped using the
	    mmap() function.

  AC_MMAP_DATA
	    The area that normally contains data regions of relocatable files
	    loaded by the program loader, or otherwise mapped using the
	    mmap() function.

  AC_MMAP_BSS
	    The area that normally contains the bss regions of relocatable
	    files loaded by the program loader, or anonymous regions mapped
	    using the mmap() function.

  The sys/addrconf.h header file also defines the AC_N_AREAS symbol to be the
  number of distinct areas currently defined for this system.  Normally, the
  buffer parameter supplied to the getaddressconf() function should be large
  enough to hold information for AC_N_AREAS regions.  If buffer is not large
  enough, the remaining information is truncated.  The getaddressconf() call
  fills in the first AC_N_AREAS records in the	user-supplied buffer with the
  address configuration information for this system, as described above.

RETURN VALUES
  Upon successful completion, the number of bytes actually written to the
  user's buffer is returned.  If an error occurs, -1 is returned, and errno
  is set to indicate the error.



ERRORS
  If the getaddressconf() function fails, errno may be set to the following
  value:

  [EFAULT]  The address specified for buffer is not valid.

RELATED INFORMATION
  Functions: mmap(2), exec(2), exec_with_loader(2), brk(2)

Index for Section 2

Alphabetical listing for G

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