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<concept id="GUID-C13DFF33-7C54-5113-9277-CAD96215F075" xml:lang="en"><title>RAM

Zones</title><shortdesc>A RAM zone is a physically contiguous section of RAM address space

that has a preference value and a unique ID.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p> A base port must define the RAM zones for a phone. The Kernel uses RAM

zones to decide how to allocate RAM pages so that: </p>

<ul>

<li id="GUID-B407EC83-9493-5D76-9CAF-EFA86F06870E"><p>only the necessary parts

of a device’s RAM ICs are powered and refreshed. This may reduce power consumption. </p> </li>

<li id="GUID-77601E75-5D27-5283-9693-329F29370FE0"><p>pre-determined regions

of physically contiguous RAM can be used for a specific function when required.

For example, a buffer required by a camera peripheral. </p> </li>

</ul>

<p>The system attempts to allocate memory in a preferred RAM zone. A preferred

RAM zone is a zone that has a lower preference value than another. </p>

<p>All methods that perform operations on a specific RAM zone take the unique

ID of the RAM zone as a parameter. </p>

<p>RAM zones are specified only once during the boot process by the base port.

The base port must do this in its ASSP/Variant in its implementation of the <xref href="GUID-A83A7C3C-7DC0-3B9C-842F-70FCC751365D.dita#GUID-A83A7C3C-7DC0-3B9C-842F-70FCC751365D/GUID-63F2135B-4264-3B3B-9B68-656A89BF7EE9"><apiname>Asic::Init1()</apiname></xref> function. </p>

</conbody><related-links>

<link href="GUID-26621CA5-B686-53FB-AF3E-96CDD38C8520.dita"><linktext>Physical

RAM                 Defragmentation</linktext></link>

<link href="GUID-C376486D-B9BF-5D00-8B1A-1527FC1F83AD.dita"><linktext>RAM Zone

Tutorial</linktext></link>