Int 31H Function 0603H
Relock Real Mode Region
Relocks a memory region that was previously declared as pageable with
the Mark Real Mode Region as Pageable function (Int 31H Function 0602H).
AX = 0603H
BX:CX = starting linear address of memory to relock
SI:DI = size of region to relock (bytes)
if function successful
Carry flag = clear
if function unsuccessful
Carry flag = set
AX = error code
|8002H||invalid state (region not marked as
|8013H||physical memory unavailable|
|8025H||invalid linear address (region is above 1
- If the function returns an error, none of the memory has been
- If the specified region overlaps part of a page at the beginning
or end of the region, the page(s) will not be relocked.
- This function is ignored by DPMI implementations that do not
support virtual memory; the function will return the Carry flag clear
to indicate success, but has no other effect. DPMI hosts which
support virtual memory may also choose to ignore this function, but
such hosts must be able to handle page faults transparently at
arbitrary points during a client's execution, including within
interrupt and exception handlers.
- If Function 0602H is implemented as a
"no-operation" on a particular DPMI host, this function will likewise
do nothing. In other words, this function should not be used to lock
memory, but only to restore the default state of the host's
conventional memory locking.