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1<h2>vm_copy</h2>
2<hr>
3<p>
4<strong>Function</strong> - Copy a region of virtual memory.
5<h3>SYNOPSIS</h3>
6<pre>
7<strong>kern_return_t   vm_copy</strong>
8                <strong>(vm_task_t</strong>            <var>target_task</var>,
9                 <strong>vm_address_t</strong>      <var>source_address</var>,
10                 <strong>vm_size_t</strong>                  <var>count</var>,
11                 <strong>vm_address_t</strong>        <var>dest_address</var><strong>);</strong>
12</pre>
13<h3>PARAMETERS</h3>
14<dl>
15<p>
16<dt> <var>target_task</var>
17<dd>
18[in task send right]
19The port for the task whose memory is to be copied.
20<p>
21<dt> <var>source_address</var>
22<dd>
23[in scalar]
24The starting address for the source region.
25<p>
26<dt> <var>count</var>
27<dd>
28[in scalar]
29The number of bytes in the source region.  The number of
30bytes must convert to an integral number of virtual pages.
31<p>
32<dt> <var>dest_address</var>
33<dd>
34[in scalar]
35The starting address for the destination region.
36</dl>
37<h3>DESCRIPTION</h3>
38<p>
39The <strong>vm_copy</strong> function copies a source region to a destination
40region within the
41same task's virtual memory.  It is semantically equivalent to
42<strong>vm_read</strong> followed
43by <strong>vm_write</strong>.  The destination region can overlap the source region.
44<p>
45The destination region must already be allocated.  The source region must be
46readable, and the destination region must be writable.
47<h3>NOTES</h3>
48<p>
49This interface is machine word length specific because of the virtual address
50parameter.
51<h3>RETURN VALUES</h3>
52<dl>
53<p>
54<dt> <strong>KERN_PROTECTION_FAILURE</strong>
55<dd>
56The source region is protected against reading, or the destination
57region is protected against writing.
58<p>
59<dt> <strong>KERN_INVALID_ADDRESS</strong>
60<dd>
61An address is illegal or specifies a non-allocated region, or there is not
62enough memory following one of the addresses.
63</dl>
64<h3>RELATED INFORMATION</h3>
65<p>
66Functions:
67<a href="vm_protect.html"><strong>vm_protect</strong></a>,
68<a href="vm_read.html"><strong>vm_read</strong></a>,
69<a href="vm_write.html"><strong>vm_write</strong></a>,
70<a href="host_page_size.html"><strong>host_page_size</strong></a>.
71