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<h2>
<a name="1204551"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">6.2 Default placements</font>
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<p>
<a name="1204552"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Each compiled object file has associated with it some default sections into which any code or data, which has not been placed by use of an <font size=2 face=Courier><strong>ST_section</strong></font> pragma, is placed. These default sections are listed below.</font>
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<p>
<a name="1205867"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><em>Note: The chevrons <font face="Verdana, Arial, Helvetica, sans-serif"><i><></i></font> form part of the name.</em></font>
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<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204553"> </a><font size=2 face=Courier><strong><em><Filename_text></em></strong></font> Contains all functions which have not been explicitly placed. It also contains any anonymous literals used by the function, for example, literal strings.</font></p>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204554"> </a><font size=2 face=Courier><strong><em><Filename_const></em></strong></font> Contains all <font size=2 face=Courier><strong>const</strong></font> data items which have not been explicitly placed.</font></p>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204555"> </a><font size=2 face=Courier><strong><em><Filename_data></em></strong></font> Contains all initialized non-<font size=2 face=Courier><strong>const</strong></font> data items which have not been explicitly placed.</font></p>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204557"> </a><font size=2 face=Courier><strong><em><Filename_bss></em></strong></font> Contains all uninitialized non-<font size=2 face=Courier><strong>const</strong></font> data items which have not been explicitly placed. (By default <font size=2 face=Courier><strong><em><Filename_bss></em></strong></font> sections are cleared to zero, but they can be marked to be left uninitialized at boot time; see below).</font></p>
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<p>
<a name="1204558"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">The use of the filename in the section names allows placement of items at higher granularity, for example, all functions in an object file or all <font size=2 face=Courier><strong>const</strong></font> data in an object file.</font>
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<p>
<a name="1206072"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">The <font size=2 face=Courier><strong>place</strong></font> command <font size=2 face=Courier><strong>noinit</strong></font> option can be used to mark a BSS section as a <font size=2 face=Courier><strong>noinit</strong></font> section. This is treated the same as a BSS section except it is not initialized at boot time to all zeroes. This enables the memory contents to be preserved during boot time and for example, enables the data to be mapped to a peripheral device which should not be written to at boot time.</font>
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<p>
<a name="1204560"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">In order to keep the size of the boot code down initialization of the BSS section is not optimized. Normally this is fast enough, however, large arrays in the source code may increase the size of the BSS section, which in turn slows down the initialization. Allocating large arrays or large C variables into named sections and placing such sections into memory segments marked with the <font face="Verdana, Arial, Helvetica, sans-serif"><b>noinit</b></font> option, ensures they are not initialized at boot time. If any of the variables require initialization this can be done using the <font size=2 face=Courier><strong>memset</strong></font> function from the C source code.</font>
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<p>
<a name="1204561"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">All sections within the link which are not explicitly placed can be referenced collectively by predefined section names:</font>
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<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204563"> </a><font size=2 face=Courier><strong>def_code 牋</strong></font>all unplaced code sections,</font></p>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204565"> </a><font size=2 face=Courier><strong>def_const ⌨️ 快捷键说明
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