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<concept id="GUID-96F07979-3863-5198-AF8B-4ACC1193CF3E" xml:lang="en"><title>Level
2 Cache Tutorial</title><shortdesc>This topic describes how to configure the base port to use the
ARM L210 cache or L220 cache controllers in ARM processors. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<p>Cache is a fast buffer that keeps copies of recently accessed memory. </p>
<section id="GUID-6ECBAFBD-87A5-4CB2-8A83-24F5208A58DA"><title>L210 Cache</title> <p>In
the <filepath>variant.mmh</filepath> file, set the macro: </p> <codeblock id="GUID-FB4E4E84-828F-5FD6-A296-F55FA8F7C25D" xml:space="preserve">__ARM_L210_CACHE__</codeblock> <p>You
must also set a L210 Cache macro and initialise Level 2 cache in the Bootstrap.
See <xref href="GUID-4A910E9F-E881-51D7-A84A-CBC6AC343FD1.dita">Level 2 Cache Macros</xref> and <xref href="GUID-F67FA7B5-F6D1-5C5C-8E10-A8E317A778E4.dita#GUID-F67FA7B5-F6D1-5C5C-8E10-A8E317A778E4/GUID-C111DA06-F7EE-5E70-8D86-26BA2213B506">HardwareInitialise()</xref>. </p> <p>The
L210 cache is switched on by generic Symbian platform code before jumping
into the kernel code. The cache is switched on after the MMU and L1 cache
are enabled. </p> </section>
<section id="GUID-D713DF71-C896-45EA-86D6-55E5FF9CFABC"><title>L220 Cache</title> <p>In
the <filepath>variant.mmh</filepath> file, set the macro: </p> <codeblock id="GUID-8DCEE6B7-E852-5B3D-AFE7-E512DCAA73C0" xml:space="preserve">__ARM_L220_CACHE__</codeblock> <p>You
must also set a L220 Cache macro and initialise Level 2 cache in the Bootstrap.
See <xref href="GUID-4A910E9F-E881-51D7-A84A-CBC6AC343FD1.dita">Level 2 Cache Macros</xref> and <xref href="GUID-F67FA7B5-F6D1-5C5C-8E10-A8E317A778E4.dita#GUID-F67FA7B5-F6D1-5C5C-8E10-A8E317A778E4/GUID-C111DA06-F7EE-5E70-8D86-26BA2213B506">HardwareInitialise()</xref>. </p> <p>Code
to switch on the L220 cache on must be provided by the base port. You can
do this in the <xref href="GUID-F67FA7B5-F6D1-5C5C-8E10-A8E317A778E4.dita#GUID-F67FA7B5-F6D1-5C5C-8E10-A8E317A778E4/GUID-C111DA06-F7EE-5E70-8D86-26BA2213B506">HardwareInitialise()</xref> function
or the <xref href="GUID-B3F6FC45-3BF0-5F92-8325-44C705BA47AE.dita#GUID-B3F6FC45-3BF0-5F92-8325-44C705BA47AE/GUID-EEF889E7-915F-57E9-8E2D-DC17B24C7728">BTF_Final()</xref> function
in the Bootstrap. </p> </section>
</conbody></concept>