author | Graeme Price <GRAEME.PRICE@NOKIA.COM> |
Fri, 15 Oct 2010 14:32:18 +0100 | |
changeset 15 | 307f4279f433 |
permissions | -rw-r--r-- |
15
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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changeset
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<?xml version="1.0" encoding="utf-8"?> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
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<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
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<!-- This component and the accompanying materials are made available under the terms of the License |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
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"Eclipse Public License v1.0" which accompanies this distribution, |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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|
5 |
and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
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|
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<!-- Initial Contributors: |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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Nokia Corporation - initial contribution. |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
8 |
Contributors: |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
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--> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
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<!DOCTYPE concept |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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|
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PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
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<concept id="GUID-1A72F75A-1930-5C32-93B7-20F4934BCFAA" xml:lang="en"><title>ROM |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
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Paging Overview</title><shortdesc>Memory may be conserved by only loading the parts of an execute |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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in place (XIP) image that are required at any given time. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
15 |
<section id="GUID-3CEEAF8D-F97A-55A8-AD34-5578A149EEFB"><title>Description</title> <p>If |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
16 |
an XIP ROM image is stored on an XIP media such as NOR flash, it does not |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
17 |
have to be copied into main memory before it can be executed. If it is stored |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
18 |
on non-XIP media, such as NAND flash, then it must be copied into main memory |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
19 |
before it can be executed. The entire XIP image can run to many megabytes, |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
20 |
and therefore use a lot of main memory. If ROM Paging is used, then only those |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
21 |
sections of the XIP image which are required are loaded into memory. Additional |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
22 |
sections are loaded as and when they are needed, and sections which have not |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
23 |
been used in some time can be discarded. The overall effect is to leave more |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
24 |
memory available for applications. </p> <p><add links to memory mapping, |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
25 |
NOR NAND> </p> <p>If the ROM image is in a non-XIP ROM it has to be loaded |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
26 |
into RAM before it can be executed. The ROM image is split into two parts: </p> <ul> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
27 |
<li id="GUID-74FB13BD-87C6-5591-B522-E2853BB89B76"><p>Paged </p> </li> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
28 |
<li id="GUID-E3226DFC-D8C3-5E31-A188-D9549697C210"><p>Unpaged </p> </li> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
29 |
</ul> <p>The unpaged part of the ROM image is loaded by the bootloader and |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
30 |
it always present in RAM. The paged part of the ROM image is paged in on demand. </p> </section> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
31 |
<section id="GUID-B4DB09C1-B16C-4A45-ADCF-C0A10D577CFA"><title>Using ROM Paging</title> <p>The type of paging used and the |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
32 |
area of memory to use first is specified in the oby and mmp files and then |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
33 |
built by using specific parameters in the buildrom utility. </p> </section> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
34 |
</conbody><related-links> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
35 |
<link href="GUID-0AFF5666-6BF9-5022-ADBC-5EFFA743B288.dita"><linktext>ROM Paging |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
36 |
Guide</linktext></link> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
37 |
<link href="GUID-5A71755A-E67F-5007-8C55-5B8FA65B3C04.dita"><linktext>ROM file |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
38 |
system</linktext></link> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
39 |
<link href="GUID-D6C2202C-778C-558A-97AA-649CD6DB5E87.dita"><linktext>ROFS file |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
40 |
system</linktext></link> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
diff
changeset
|
41 |
</related-links></concept> |