minix/lib/libc/sys/mremap.2
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

109 lines
3.2 KiB
Groff

.\" $NetBSD: mremap.2,v 1.3 2008/02/16 17:45:39 tnn Exp $
.\"
.\" Copyright (c) 2007 Thomas Klausner and Joerg Sonnenberger
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" ------------------------------------------------------------
.Dd February 14, 2008
.Dt MREMAP 2
.Os
.Sh NAME
.Nm mremap
.Nd re-map a virtual memory address
.\" ------------------------------------------------------------
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/mman.h
.Ft void *
.Fn mremap "void *oldp" "size_t oldsize" "void *newp" "size_t newsize" \
"int flags"
.\" ------------------------------------------------------------
.Sh DESCRIPTION
The
.Fn mremap
function resizes the mapped range (see
.Xr mmap 2 )
starting at
.Ar oldp
and having size
.Ar oldsize
to
.Ar newsize .
The following arguments can be
.Dv OR Ap ed
together in the
.Ar flags
argument:
.Bl -tag -width XXMAPXALIGNEDXnXX
.It Dv MAP_ALIGNED Ns Pq Ar n
The allocation should be aligned to the given boundary, i.e. ensure
that the lowest
.Ar n
bits of the address are zero.
The parameter
.Ar n
should be the base 2 logarithm of the desired alignment (e.g., to
request alignment to 16K, use 14 as the value for n).
The alignment must be equal to or greater than the platform's page
size as returned by
.Xr sysconf 3
with the
.Dv _SC_PAGESIZE
request.
.It Dv MAP_FIXED
.Ar newp
is tried and
.Fn mremap
fails if that address can't be used as new base address for the range.
Otherwise,
.Ar oldp
and
.Ar newp
are used as hints for the position, factoring in the given alignment.
.El
.Sh RETURN VALUES
.Fn mremap
returns the new address or
.Dv MAP_FAILED ,
if the remap failed.
.Sh HISTORY
The
.Fn mremap
system call appeared in
.Nx 5.0 .
It was based on the code that supports
.Fn mremap
compatibility for Linux binaries.
.Sh COMPATIBILITY
The semantics of
.Fn mremap
differ from the one provided by glibc on Linux in that the
.Ar newp
argument was added and a different set of
.Ar flags
are implemented.
.Sh SEE ALSO
.Xr mmap 2 ,
.Xr munmap 2