static/netbsd/man4/man4.sparc/mem.4 4.html


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<table class="head">
  <tr>
    <td class="head-ltitle">MEM(4)</td>
    <td class="head-vol">Device Drivers Manual (sparc)</td>
    <td class="head-rtitle">MEM(4)</td>
  </tr>
</table>
<div class="manual-text">
<section class="Sh">
<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1>
<p class="Pp"><code class="Nm">mem</code>, <code class="Nm">kmem</code> &#x2014;
    <span class="Nd">Sun main memory access driver</span></p>
</section>
<section class="Sh">
<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
<p class="Pp">The file <span class="Pa">/dev/mem</span> is an interface to the
    physical memory of the computer. Byte offsets in this file are interpreted
    as physical memory addresses. Reading and writing this file is equivalent to
    reading and writing memory itself. An error will be returned if an attempt
    is made to reference an offset outside of
  <span class="Pa">/dev/mem</span>.</p>
<p class="Pp">Kernel virtual memory is accessed via the file
    <span class="Pa">/dev/kmem</span> in the same manner as
    <span class="Pa">/dev/mem</span>. Only kernel virtual addresses that are
    currently mapped to memory are allowed.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="SPARC"><a class="permalink" href="#SPARC">SPARC</a></h1>
<p class="Pp">On the SPARC, physical memory may be discontiguous; kernel virtual
    memory begins at <code class="Li">0xf0000000</code>.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="FILES"><a class="permalink" href="#FILES">FILES</a></h1>
<dl class="Bl-tag Bl-compact">
  <dt><span class="Pa">/dev/mem</span></dt>
  <dd style="width: auto;">&#x00A0;</dd>
  <dt><span class="Pa">/dev/kmem</span></dt>
  <dd style="width: auto;">&#x00A0;</dd>
</dl>
</section>
<section class="Sh">
<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1>
<p class="Pp">The files <code class="Nm">mem</code> and
    <code class="Nm">kmem</code> appeared in <span class="Ux">Version&#x00A0;6
    AT&amp;T UNIX</span>.</p>
</section>
</div>
<table class="foot">
  <tr>
    <td class="foot-date">June 5, 1993</td>
    <td class="foot-os">NetBSD 10.1</td>
  </tr>
</table>