source: clfs-embedded/BOOK/cross-tools/arm/variables.xml @ a5cbaf25

Last change on this file since a5cbaf25 was a5cbaf25, checked in by Andrew Bradford <andrew@…>, 9 years ago

arm-fpu: Update recommendations, remove wrong fpus

Update recommendations to:
ARM9 with soft
Cortex-A with hard

Remove soft-vfp and none fpu types, they aren't valid.

  • Property mode set to 100644
File size: 7.1 KB
Line 
1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4  <!ENTITY % general-entities SYSTEM "../../general.ent">
5  %general-entities;
6]>
7
8<sect1 id="ch-cross-tools-variables">
9  <?dbhtml filename="variables.html"?>
10
11  <title>Build Variables</title>
12
13  <bridgehead renderas="sect4">Setting Host and Target</bridgehead>
14
15  <para os="a">During the building of the cross-compile tools, you will need to
16  set a few variables that will be dependent on your particular needs.
17  You will need to select the target triplet for the target architecture, the CPU
18  endianess, the CPU architecture, the CPU mode, the CPU floating point hardware
19  availability, and (if available) the type of floating point hardware. If you
20  do not know what values can be chosen for each of these, you can use the
21  tables at the bottom of this page as a reference.</para>
22
23  <para os="a1">Most ARM processors are little endian, it is a safe choice.  If
24  your processor is an ARM9, good choices include: triplet of
25  armv5l-unknown-linux-uclibeabi, ARM arch of armv5t, and float of soft.  ARM9
26  processors do not usually have hardware floating point abilities. If your
27  processor is a Cortex-A series, which often have hardware floating point
28  capability, good choices include: triplet of
29  armv7a-unknown-linux-uclibceabi, ARM arch of armv7-a, float of hard, and fpu
30  of vfpv3-d16.</para>
31
32  <para os="a2">First, set the host and target triplets:</para>
33
34  <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
35  href="../common/variables.xml"
36  xpointer="xpointer(//*[@os='b'])"/>
37
38  <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
39  href="../common/variables.xml"
40  xpointer="xpointer(//*[@os='c'])"/>
41
42<screen os="d"><userinput>export CLFS_ARCH=arm
43export CLFS_ENDIAN="<replaceable>[endianess]</replaceable>"</userinput></screen>
44
45  <para os="e">Choose the ARM architecture (see table below) and mode of
46  your CPU:</para>
47
48<screen os="f"><userinput>export CLFS_ARM_ARCH="<replaceable>[architecture]</replaceable>"
49export CLFS_ARM_MODE="<replaceable>[arm or thumb]</replaceable>"</userinput></screen>
50
51  <para os="f1">If your target CPU has hardware floating point support (not all
52  ARM CPUs do), then set the following CLFS_FLOAT variable to either "hard" or
53  "softfp".  Use "softfp" if you need to integrate binaries compiled with
54  "soft".  Use "hard" if you don't.  If your target CPU does not have hard
55  floating point support, set the following CLFS_FLOAT vairable to
56  "soft".</para>
57
58<screen os="f2"><userinput>export CLFS_FLOAT="<replaceable>[hard, softfp, or soft]"</replaceable></userinput></screen>
59
60  <para os="f3">If you chose either "hard" or "softfp" for CLFS_FLOAT, you now
61  need to set which floating point hardware is actually included (see table below)
62  with your ARM CPU:</para>
63
64<screen os="f4"><userinput>export CLFS_FPU="<replaceable>[fpu version]</replaceable>"</userinput></screen>
65
66  <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
67  href="../common/variables.xml"
68  xpointer="xpointer(//*[@os='g'])"/>
69
70<screen os="h"><userinput>echo export CLFS_HOST=\""${CLFS_HOST}\"" &gt;&gt; ~/.bashrc
71echo export CLFS_TARGET=\""${CLFS_TARGET}\"" &gt;&gt; ~/.bashrc
72echo export CLFS_ARCH=\""${CLFS_ARCH}\"" &gt;&gt; ~/.bashrc
73echo export CLFS_ENDIAN=\""${CLFS_ENDIAN}\"" &gt;&gt; ~/.bashrc
74echo export CLFS_ARM_ARCH=\""${CLFS_ARM_ARCH}\"" &gt;&gt; ~/.bashrc
75echo export CLFS_ARM_MODE=\""${CLFS_ARM_MODE}\"" &gt;&gt; ~/.bashrc
76echo export CLFS_FLOAT=\""${CLFS_FLOAT}\"" &gt;&gt; ~/.bashrc
77echo export CLFS_FPU=\""${CLFS_FPU}\"" &gt;&gt; ~/.bashrc</userinput></screen>
78
79  <table os="i">
80    <title>Example Processor Type, ABI, and  Target Triplets</title>
81    <?dbfo table-width="7in" ?>
82
83    <tgroup cols="4">
84
85      <colspec colnum="1" colwidth="2.5in" colname="Processor"/>
86      <colspec colnum="2" colwidth="1in" colname="Endianess"/>
87      <colspec colnum="3" colwidth="1in" colname="ABI"/>
88      <colspec colnum="4" colwidth="2.5in" colname="Triplet"/>
89
90      <thead>
91        <row>
92          <entry>Processor</entry>
93          <entry>Endianess</entry>
94          <entry>ABI</entry>
95          <entry>Target Triplet</entry>
96        </row>
97      </thead>
98
99      <tbody>
100        <row>
101          <entry>Generic arm, version 5</entry>
102          <entry>little</entry>
103          <entry>EABI</entry>
104          <entry>armv5l-unknown-linux-uclibceabi</entry>
105        </row>
106        <row>
107          <entry>Generic arm, version 5</entry>
108          <entry>big</entry>
109          <entry>EABI</entry>
110          <entry>armv5b-unknown-linux-uclibceabi</entry>
111        </row>
112        <row>
113          <entry>Generic arm</entry>
114          <entry>little</entry>
115          <entry>EABI</entry>
116          <entry>arm-unknown-linux-uclibceabi</entry>
117        </row>
118        <row>
119          <entry>Generic arm, version 7-a </entry>
120          <entry>little</entry>
121          <entry>EABI</entry>
122          <entry>armv7a-unknown-linux-uclibceabi</entry>
123        </row>
124      </tbody>
125
126    </tgroup>
127
128  </table>
129
130  <table os="j">
131    <title>ARM Archiecture Choices</title>
132    <?dbfo table-width="4in" ?>
133
134    <tgroup cols="4">
135
136      <colspec colnum="1" colwidth="1in" colname="Arch Choice"/>
137      <colspec colnum="2" colwidth="1in" colname="Arch Choice"/>
138      <colspec colnum="3" colwidth="1in" colname="Arch Choice"/>
139      <colspec colnum="4" colwidth="1in" colname="Arch Choice"/>
140
141      <tbody>
142        <row>
143          <entry>armv4t</entry>
144          <entry>armv5</entry>
145          <entry>armv5t</entry>
146          <entry>armv5te</entry>
147        </row>
148        <row>
149          <entry>armv6</entry>
150          <entry>armv6j</entry>
151          <entry>armv6t2</entry>
152          <entry>armv6z</entry>
153        </row>
154        <row>
155          <entry>armv6zk</entry>
156          <entry>armv6-m</entry>
157          <entry>armv7</entry>
158          <entry>armv7-a</entry>
159        </row>
160        <row>
161          <entry>armv7-r</entry>
162          <entry>armv7-m</entry>
163        </row>
164      </tbody>
165    </tgroup>
166  </table>
167
168  <table os="j">
169    <title>ARM Hard Floating Point Versions</title>
170    <?dbfo table-width="4in" ?>
171
172    <tgroup cols="4">
173
174      <colspec colnum="1" colwidth="1in" colname="FPU Choice"/>
175      <colspec colnum="2" colwidth="1in" colname="FPU Choice"/>
176      <colspec colnum="3" colwidth="1in" colname="FPU Choice"/>
177      <colspec colnum="4" colwidth="1in" colname="FPU Choice"/>
178
179      <tbody>
180        <row>
181          <entry>fpa</entry>
182          <entry>fpe2</entry>
183          <entry>fpe3</entry>
184          <entry>maverick</entry>
185        </row>
186        <row>
187          <entry>vfp</entry>
188          <entry>vfpv3</entry>
189          <entry>vfpv3-fp16</entry>
190          <entry>vfpv3-d16</entry>
191        </row>
192        <row>
193          <entry>vfpv3-d16-fp16</entry>
194          <entry>vfpv3xd</entry>
195          <entry>vfpv3xd-fp16</entry>
196          <entry>neon</entry>
197        </row>
198        <row>
199          <entry>neon-fp16</entry>
200          <entry>vfpv4</entry>
201          <entry>vfpv4-d16</entry>
202          <entry>fpv4-sp-d16</entry>
203        </row>
204        <row>
205          <entry>neon-vfpv4</entry>
206        </row>
207      </tbody>
208    </tgroup>
209  </table>
210
211</sect1>
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