Get Page Attributes

Returns the attributes of one or more pages within a linear
memory block previously allocated with Int 31H Function
0504H.

Call With:

   AX     = 0506H
   ESI    = memory block handle
   EBX    = base offset in memory block of page (or of first
           page, if requesting attributes for multiple
           pages)
   ECX    = number of pages
   ES:EDX = selector:offset of a buffer to receive page
           attributes, 1 word (16-bits) per page (see Note)

Returns:

   if function successful
   Carry flag= clear

   and buffer at ES:EDX filled in with page attributes (see
   Note)

   if function unsuccessful
   Carry flag= set
   AX     = error code
           8001H   unsupported function (16-bit host)
           8023H   invalid handle (in ESI)
           8025H   invalid linear address (Specified range
                   is not within specified block)

Notes:

o  A DPMI 1.0 host that is 16-bit only will not support this
   function.
o  A 16-bit client of a 32-bit DPMI 1.0 host can use this
   function.
o  If EBX is not aligned, it will be rounded down to the
   next lower page boundary.
o  The specified buffer is filled in by the DPMI host with
   the attributes of the requested pages, 1 word (16-bits)
   per page, in the following format:

   Bits      Significance
   0-2       page type (0-7)
             Value  Meaning
             0      uncommitted page
             1      committed page
             2      mapped page
             3-7    currently unused
   3         0 = page is read-only
             1 = page is read/write
   4         0 = accessed/dirty bits not available for this
   page
             1 = accessed/dirty bits are supplied for this
   page in bits 5-6
   5         0 = page has not been accessed (if bit 4=1)
             1 = page has been accessed (if bit 4=1)
   6         0 = page has not been modified (if bit 4=1)
             1 = page has been modified (if bit 4=1)
   7-15      reserved, currently zero

o  Mapped pages can only occur in memory blocks under DPMI
   hosts that support the Device Mapping capability or the
   Conventional Memory Mapping capability.  See Int 31H
   Functions 0401H, 0508H, and 0509H.
o  The dirty and accessed bits are only supplied if the DPMI
   host supports the Page Accessed/Dirty capability.  DPMI
   hosts that support this capability are required to return
   dirty and accessed bits for all committed pages and for
   mapped pages created with the Map Conventional Memory
   call (Int 31H Fn 0509H).  However, dirty and
   accessed bits may not be returned for individual mapped
   pages created with the Map Device call (Int 31H Function
   0508H) if the host is using page table entries (PTEs) to
   virtualize the device.