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ws_map_region(9r)
NAME
  ws_map_region - Graphics: Maps kernel addresses into the process virtual
  address space

SYNOPSIS
  caddr_t ws_map_region(
	  caddr_t kaddr,
	  caddr_t uaddr,
	  register int nbytes,
	  int how,
	  int *erroraddr );

ARGUMENTS
  kaddr
      Specifies the kernel address of the memory to be mapped.

  uaddr
      Specifies the address of the current process where kaddr is to be
      mapped.  This argument should be NULL unless you need to map kernel
      addresses to a specific location in the process's address.

  nbytes
      Specifies the size (in bytes) of the memory to be mapped.

  how Specifies the access mode in octal for the physical memory segment.

  erroraddr
      Specifies a pointer to the error number (errno) address, which returns
      NULL if the memory cannot be mapped.

DESCRIPTION
  The ws_map_region routine takes the physical addresses that kaddr specifies
  and maps them into the current process's virtual address space. This
  routine is typcially called by map_unmap_screen to map the physical address
  of the defined screen into virtual address space.

NOTES
  Each call to this routine allocates one memory segment. Because shared
  memory segments are expensive system resources, you should minimize the
  number of separate areas mapped.









RETURN VALUES
  On success, the ws_map_region routine returns the address of the memory
  map. If the memory could not be mapped, it returns a NULL pointer.


EXAMPLES
  The following example shows how the myvga_map_unmap_screen function calls
  ws_map_region to map I/O registers to user space:

       int
       myvga_map_unmap_screen(caddr_t screen_handle,
			      ws_depth_descriptor *depths,
			      ws_screen_descriptor *screen,
			      ws_map_control *mp)
       {

       .
       .
       .

	   dp->pixmap = ws_map_region(temp, NULL, nbytes,
		   0600, (int *)NULL);

       .
       .
       .

       }

FILES
  /usr/sys/include/sys/workstation.h

  /usr/sys/include/sys/wsdevice.h

Index for Section 9

Alphabetical listing for W

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