|
168
|
1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
|
|
|
2 <HTML
|
|
|
3 ><HEAD
|
|
|
4 ><TITLE
|
|
|
5 >Linking Scripts</TITLE
|
|
|
6 ><META
|
|
|
7 NAME="GENERATOR"
|
|
|
8 CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
|
|
|
9 REL="HOME"
|
|
|
10 TITLE="LW Tool Chain"
|
|
|
11 HREF="index.html"><LINK
|
|
|
12 REL="UP"
|
|
|
13 TITLE="LWLINK"
|
|
|
14 HREF="c662.html"><LINK
|
|
|
15 REL="PREVIOUS"
|
|
|
16 TITLE="Linker Operation"
|
|
|
17 HREF="x762.html"><LINK
|
|
|
18 REL="NEXT"
|
|
|
19 TITLE="Format Specific Linking Notes"
|
|
|
20 HREF="x810.html"></HEAD
|
|
|
21 ><BODY
|
|
|
22 CLASS="SECTION"
|
|
|
23 BGCOLOR="#FFFFFF"
|
|
|
24 TEXT="#000000"
|
|
|
25 LINK="#0000FF"
|
|
|
26 VLINK="#840084"
|
|
|
27 ALINK="#0000FF"
|
|
|
28 ><DIV
|
|
|
29 CLASS="NAVHEADER"
|
|
|
30 ><TABLE
|
|
|
31 SUMMARY="Header navigation table"
|
|
|
32 WIDTH="100%"
|
|
|
33 BORDER="0"
|
|
|
34 CELLPADDING="0"
|
|
|
35 CELLSPACING="0"
|
|
|
36 ><TR
|
|
|
37 ><TH
|
|
|
38 COLSPAN="3"
|
|
|
39 ALIGN="center"
|
|
|
40 >LW Tool Chain</TH
|
|
|
41 ></TR
|
|
|
42 ><TR
|
|
|
43 ><TD
|
|
|
44 WIDTH="10%"
|
|
|
45 ALIGN="left"
|
|
|
46 VALIGN="bottom"
|
|
|
47 ><A
|
|
|
48 HREF="x762.html"
|
|
|
49 ACCESSKEY="P"
|
|
|
50 >Prev</A
|
|
|
51 ></TD
|
|
|
52 ><TD
|
|
|
53 WIDTH="80%"
|
|
|
54 ALIGN="center"
|
|
|
55 VALIGN="bottom"
|
|
|
56 >Chapter 4. LWLINK</TD
|
|
|
57 ><TD
|
|
|
58 WIDTH="10%"
|
|
|
59 ALIGN="right"
|
|
|
60 VALIGN="bottom"
|
|
|
61 ><A
|
|
|
62 HREF="x810.html"
|
|
|
63 ACCESSKEY="N"
|
|
|
64 >Next</A
|
|
|
65 ></TD
|
|
|
66 ></TR
|
|
|
67 ></TABLE
|
|
|
68 ><HR
|
|
|
69 ALIGN="LEFT"
|
|
|
70 WIDTH="100%"></DIV
|
|
|
71 ><DIV
|
|
|
72 CLASS="SECTION"
|
|
|
73 ><H1
|
|
|
74 CLASS="SECTION"
|
|
|
75 ><A
|
|
|
76 NAME="AEN776"
|
|
|
77 >4.3. Linking Scripts</A
|
|
|
78 ></H1
|
|
|
79 ><P
|
|
|
80 >A linker script is used to instruct the linker about how to assemble the
|
|
|
81 various sections into a completed binary. It consists of a series of
|
|
|
82 directives which are considered in the order they are encountered.</P
|
|
|
83 ><P
|
|
|
84 >The sections will appear in the resulting binary in the order they are
|
|
|
85 specified in the script file. If a referenced section is not found, the linker will behave as though the
|
|
|
86 section did exist but had a zero size, no relocations, and no exports.
|
|
|
87 A section should only be referenced once. Any subsequent references will have
|
|
|
88 an undefined effect.</P
|
|
|
89 ><P
|
|
|
90 >All numbers are in linking scripts are specified in hexadecimal. All directives
|
|
|
91 are case sensitive although the hexadecimal numbers are not.</P
|
|
|
92 ><P
|
|
|
93 >A section name can be specified as a "*", then any section not
|
|
|
94 already matched by the script will be matched. The "*" can be followed
|
|
|
95 by a comma and a flag to narrow the section down slightly, also.
|
|
|
96 If the flag is "!bss", then any section that is not flagged as a bss section
|
|
|
97 will be matched. If the flag is "bss", then any section that is flagged as
|
|
|
98 bss will be matched.</P
|
|
|
99 ><P
|
|
|
100 >The following directives are understood in a linker script.</P
|
|
|
101 ><P
|
|
|
102 ></P
|
|
|
103 ><DIV
|
|
|
104 CLASS="VARIABLELIST"
|
|
|
105 ><DL
|
|
|
106 ><DT
|
|
|
107 >section <CODE
|
|
|
108 CLASS="PARAMETER"
|
|
|
109 >name</CODE
|
|
|
110 > load <CODE
|
|
|
111 CLASS="PARAMETER"
|
|
|
112 >addr</CODE
|
|
|
113 ></DT
|
|
|
114 ><DD
|
|
|
115 ><P
|
|
|
116 > This causes the section <CODE
|
|
|
117 CLASS="PARAMETER"
|
|
|
118 >name</CODE
|
|
|
119 > to load at
|
|
|
120 <CODE
|
|
|
121 CLASS="PARAMETER"
|
|
|
122 >addr</CODE
|
|
|
123 >. For the raw target, only one "load at" entry is
|
|
|
124 allowed for non-bss sections and it must be the first one. For raw targets,
|
|
|
125 it affects the addresses the linker assigns to symbols but has no other
|
|
|
126 affect on the output. bss sections may all have separate load addresses but
|
|
|
127 since they will not appear in the binary anyway, this is okay.</P
|
|
|
128 ><P
|
|
|
129 >For the decb target, each "load" entry will cause a new "block" to be
|
|
|
130 output to the binary which will contain the load address. It is legal for
|
|
|
131 sections to overlap in this manner - the linker assumes the loader will sort
|
|
|
132 everything out.</P
|
|
|
133 ></DD
|
|
|
134 ><DT
|
|
|
135 >section <CODE
|
|
|
136 CLASS="PARAMETER"
|
|
|
137 >name</CODE
|
|
|
138 ></DT
|
|
|
139 ><DD
|
|
|
140 ><P
|
|
|
141 > This will cause the section <CODE
|
|
|
142 CLASS="PARAMETER"
|
|
|
143 >name</CODE
|
|
|
144 > to load after the previously listed
|
|
|
145 section.</P
|
|
|
146 ></DD
|
|
|
147 ><DT
|
|
|
148 >entry <CODE
|
|
|
149 CLASS="PARAMETER"
|
|
|
150 >addr or sym</CODE
|
|
|
151 ></DT
|
|
|
152 ><DD
|
|
|
153 ><P
|
|
|
154 >This will cause the execution address (entry point) to be the address
|
|
|
155 specified (in hex) or the specified symbol name. The symbol name must
|
|
|
156 match a symbol that is exported by one of the object files being linked.
|
|
|
157 This has no effect for targets that do not encode the entry point into the
|
|
|
158 resulting file. If not specified, the entry point is assumed to be address 0
|
|
|
159 which is probably not what you want. The default link scripts for targets
|
|
|
160 that support this directive automatically starts at the beginning of the
|
|
|
161 first section (usually "init" or "code") that is emitted in the binary.</P
|
|
|
162 ></DD
|
|
|
163 ><DT
|
|
|
164 >pad <CODE
|
|
|
165 CLASS="PARAMETER"
|
|
|
166 >size</CODE
|
|
|
167 ></DT
|
|
|
168 ><DD
|
|
|
169 ><P
|
|
|
170 >This will cause the output file to be padded with NUL bytes to be exactly
|
|
|
171 <CODE
|
|
|
172 CLASS="PARAMETER"
|
|
|
173 >size</CODE
|
|
|
174 > bytes in length. This only makes sense for a raw target.</P
|
|
|
175 ></DD
|
|
|
176 ></DL
|
|
|
177 ></DIV
|
|
|
178 ></DIV
|
|
|
179 ><DIV
|
|
|
180 CLASS="NAVFOOTER"
|
|
|
181 ><HR
|
|
|
182 ALIGN="LEFT"
|
|
|
183 WIDTH="100%"><TABLE
|
|
|
184 SUMMARY="Footer navigation table"
|
|
|
185 WIDTH="100%"
|
|
|
186 BORDER="0"
|
|
|
187 CELLPADDING="0"
|
|
|
188 CELLSPACING="0"
|
|
|
189 ><TR
|
|
|
190 ><TD
|
|
|
191 WIDTH="33%"
|
|
|
192 ALIGN="left"
|
|
|
193 VALIGN="top"
|
|
|
194 ><A
|
|
|
195 HREF="x762.html"
|
|
|
196 ACCESSKEY="P"
|
|
|
197 >Prev</A
|
|
|
198 ></TD
|
|
|
199 ><TD
|
|
|
200 WIDTH="34%"
|
|
|
201 ALIGN="center"
|
|
|
202 VALIGN="top"
|
|
|
203 ><A
|
|
|
204 HREF="index.html"
|
|
|
205 ACCESSKEY="H"
|
|
|
206 >Home</A
|
|
|
207 ></TD
|
|
|
208 ><TD
|
|
|
209 WIDTH="33%"
|
|
|
210 ALIGN="right"
|
|
|
211 VALIGN="top"
|
|
|
212 ><A
|
|
|
213 HREF="x810.html"
|
|
|
214 ACCESSKEY="N"
|
|
|
215 >Next</A
|
|
|
216 ></TD
|
|
|
217 ></TR
|
|
|
218 ><TR
|
|
|
219 ><TD
|
|
|
220 WIDTH="33%"
|
|
|
221 ALIGN="left"
|
|
|
222 VALIGN="top"
|
|
|
223 >Linker Operation</TD
|
|
|
224 ><TD
|
|
|
225 WIDTH="34%"
|
|
|
226 ALIGN="center"
|
|
|
227 VALIGN="top"
|
|
|
228 ><A
|
|
|
229 HREF="c662.html"
|
|
|
230 ACCESSKEY="U"
|
|
|
231 >Up</A
|
|
|
232 ></TD
|
|
|
233 ><TD
|
|
|
234 WIDTH="33%"
|
|
|
235 ALIGN="right"
|
|
|
236 VALIGN="top"
|
|
|
237 >Format Specific Linking Notes</TD
|
|
|
238 ></TR
|
|
|
239 ></TABLE
|
|
|
240 ></DIV
|
|
|
241 ></BODY
|
|
|
242 ></HTML
|
|
|
243 > |
