c-loader9.html

vxworks相关论文

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<div class="CellBody"><a name="88057"> </a> <b class="library">aoutSparc</b> </div>

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<div class="CellBodyC" align="center"><a name="88084"> </a><i class="acronym_lc">a.out</i> </div>

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<div class="CellBodyC" align="center"><a name="88086"> </a>X86 </div>

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<div class="CellBodyC" align="center"><a name="88088"> </a>Aout - X86 </div>

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<div class="CellBody"><a name="88082"> </a><b class="library">aoutX86</b> </div>

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<div class="CellBodyC" align="center"><a name="88059"> </a>COFF </div>

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<div class="CellBodyC" align="center"><a name="88061"> </a> I960JX </div>

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<div class="CellBodyC" align="center"><a name="88063"> </a> coff - I960   </div>

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<div class="CellBody"><a name="88065"> </a> <b class="library">coffI960</b> </div>

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<div class="CellBodyC" align="center"><a name="88067"> </a>COFF </div>

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<div class="CellBodyC" align="center"><a name="88069"> </a> ARM7TDMI </div>

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<div class="CellBodyC" align="center"><a name="88071"> </a> coff - Arm </div>

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<div class="CellBody"><a name="88074"> </a> <b class="library">coffArm</b> </div>

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<div class="CellBodyC" align="center"><a name="88106"> </a>ELF </div>

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<div class="CellBodyC" align="center"><a name="88108"> </a> PowerPC </div>

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<div class="CellBodyC" align="center"><a name="88110"> </a> Elf - Ppc </div>

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<div class="CellBody"><a name="88104"> </a><b class="library">elfPpc</b> </div>

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<div class="CellBodyC" align="center"><a name="88112"> </a>ELF </div>

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<div class="CellBodyC" align="center"><a name="88114"> </a>MIPS </div>

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<div class="CellBodyC" align="center"><a name="88116"> </a>Elf - Mips </div>

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<div class="CellBody"><a name="88096"> </a><b class="library">elfMips</b> </div>

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<h4 class="H3"><i><a name="85280">3.9.4  &nbsp;&nbsp;The RU Interface</a></i></h4>
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<dl class="margin">

<dl class="margin">

<dd><p class="Body"><a name="85283"> </a>Relocation is highly dependent on both the OMF and the target architecture. This is why the relocation unit is a separate shared library. Only one relocator can be used at a time with a given target, so only one relocation unit is linked into the target server at run-time. The relocation unit is loaded during the OMF initialization phase (see <a href="c-loader9.html#85369"><i class="title">loadOmfFmtInit(&nbsp;)</i> on p. 114</a>).</p>
<dd><p class="Body"><a name="85287"> </a>Each relocation unit must contain the following two interface routines or entry points:</p>
</dl>

<dl class="margin">

<ul class="DashSingle" type="circle"><li><a name="85288"> </a><i class="textVariable">omfcpu</i><b class="routine"><i class="routine">SegReloc</i></b><b>(&nbsp;)</b><b class="routine"><i class="routine"> </i></b></li></ul>
<ul class="DashSingle" type="circle"><li><a name="85289"> </a><i class="textVariable">omfcpu</i><b class="routine"><i class="routine">ModuleVerify</i></b><b>(&nbsp;)</b><b class="routine"><i class="routine"> </i></b></li></ul>
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<dl class="margin">

<dd><p class="Body"><a name="85291"> </a>It may also contain an optional initialization routine:</p>
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<ul class="DashSingle" type="circle"><li><a name="85292"> </a><i class="textVariable">omfcpu</i><b class="routine"><i class="routine">RelocInit</i></b><b>(&nbsp;)</b></li></ul>
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<dd><font face="Helvetica, sans-serif" size="-1" class="sans">
<h5 class="HU"><i><a name="85294"><i class="textVariable">omfcpu</i><b class="routine"><i class="routine">RelocInit</i></b><b>(&nbsp;)</b><b class="routine"><i class="routine"> </i></b></a></i></h5>
</font><dl class="margin">

<dd><p class="Body"><a name="85295"> </a>This optional routine, if it exists in the relocation unit, is the first entry point. Its purpose is to enable the relocation unit to initialize itself.</p>
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<dd><font face="Helvetica, sans-serif" size="-1" class="sans">
<h5 class="HU"><i><a name="88144"><i class="textVariable">omfcpu</i><b class="routine"><i class="routine">ModuleVerify</i></b><b>(&nbsp;)</b><b class="routine"><i class="routine"> </i></b></a></i></h5>
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<dd><p class="Body"><a name="88145"> </a>This routine is the first entry point if there is no optional routine; it checks whether or not the given module is for the current target CPU.</p>
<dl class="margin">

<dd><pre class="Code2"><b><a name="85298">BOOL <i class="term">omfcpu</i>ModuleVerify (uint32 machtype, BOOL * pSwapIsRequired);</a></b></pre>
</dl>

<dd><p class="Body"><a name="86452"> </a>The input parameter is:</p>
</dl>

<dl class="margin">

<dd><div class="Item"><a name="86467"> </a><b class="symbol_lc">uint32 machtype</b> </div>
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<dd><div class="Indent"><a name="86468"> </a>The Module's magic number.</div>
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<dd><p class="Body"><a name="85307"> </a>The output parameter is:</p>
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<dd><div class="Item"><a name="85308"> </a><b class="symbol_UC">BOOL </b><b class="symbol_lc">* pSwapIsRequired</b></div>
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<dd><div class="Indent"><a name="85309"> </a>A pointer to a boolean saying if object module is in the opposite byte order and requires that all information be swapped.</div>
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</dl>

</dl>

<dl class="margin">

<dd><p class="Body"><a name="85310"> </a>The return value is:</p>
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<dd><div class="Item"><a name="85311"> </a><b class="symbol_UC">STATUS</b> </div>
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<dd><div class="Indent"><a name="85312"> </a><b class="symbol_UC">TRUE </b>or <b class="symbol_UC">FALSE</b>. </div>
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</dl>

</dl>

<dl class="margin">

<dd><p class="Body"><a name="85313"> </a>This routine is the underlying routine called by <b class="routine"><i class="routine">load</i></b><i class="term">Omf</i><b class="routine"><i class="routine">ModuleIsOk</i></b><b>(&nbsp;)</b><b> </b>(see <a href="c-loader9.html#85514">Example&nbsp;3-4</a>). </p>
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</dl>

<h4 class="EntityTitle"><a name="85317"><font face="Helvetica, sans-serif" size="-1" class="sans">Example 3-1:&nbsp;&nbsp;<i class="term">omfcpu</i><b class="routine"><i class="routine">ModuleVerify </i></b><b>(&nbsp;)</b> </font></a></h4>
<dl class="margin">

<dl class="margin">

<dd><pre class="Code"><b><a name="86595">/************************************************************************ 
* 
* <i class="textVariable">omfcpu</i>ModuleVerify - check the object module format for cpu target 
* 
* This routine contains the heuristic required to determine if the object 
* file belongs to the OMF handled by this OMF reader, with care for the 
* target architecture. 
* 
* It is the underlying routine for loadomfModuleIsOk(). 
* 
* RETURNS: TRUE or FALSE if the object module can't be handled. 
*/ 
 
BOOL <i class="textVariable">omfcpu</i>FoduleVerify 
    ( 
    UINT16 &nbsp;magicNumber,    /* Module's magic number */ 
    BOOL * &nbsp;SwapIsRequired  /* TRUE if header fields must be swapped */ 
    ) 
    { 
    BOOL &nbsp;&nbsp;&nbsp;moduleIsForTarget = FALSE; /* TRUE if intended for target*/ 
 
    *SwapIsRequired = FALSE; 
 
    switch(magicNumber) 
        { 
        case (SWAB_16 (MYCPUMAGIC)): 
            *SwapIsRequired = TRUE; 
            break; 
 
        case (MYCPUMAGIC): 
            moduleIsForTarget = TRUE; 
            break; 
 
        default : 
            errno = WTX_ERR_LOADER_UNKNOWN_OBJ_MODULE_FORMAT; 
    } 
    return moduleIsForTarget; 
    }</a></b></pre>
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<dd><font face="Helvetica, sans-serif" size="-1" class="sans">
<h5 class="HU"><i><a name="85353"><i class="term">omfcpu</i><b class="routine"><i class="routine">SegReloc</i></b><b>(&nbsp;)</b> </a></i></h5>
</font><dl class="margin">

<dd><p class="Body"><a name="85354"> </a>This routine performs the relocation of a given segment. The relocation process is explained in <a href="c-loader9.html#85910"><i class="title">3.9.14&nbsp;Relocating the Object Modules</i></a>, and an example of a segment relocator is also explained in <a href="c-loader9.html#85954">Example&nbsp;3-14</a>. </p>
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<font face="Helvetica, sans-serif" class="sans">
<h4 class="H3"><i><a name="85362">3.9.5  &nbsp;&nbsp;The OMF Interface</a></i></h4>
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<dl class="margin">

<dl class="margin">

<dd><p class="Body"><a name="85364"> </a>Each OMF manager must contain the following three interface routines or entry points:</p>
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<ul class="DashSingle" type="circle"><li><a name="85365"> </a><b class="routine"><i class="routine">load</i></b><i class="term">Omf</i><b class="routine"><i class="routine">FmtInit</i></b><b>(&nbsp;)</b> </li></ul>
<ul class="DashSingle" type="circle"><li><a name="85366"> </a><b class="routine"><i class="routine">load</i></b><i class="term">Omf</i><b class="routine"><i class="routine">FmtCheck</i></b><b>(&nbsp;)</b> </li></ul>
<ul class="DashSingle" type="circle"><li><a name="85367"> </a><b class="routine"><i class="routine">load</i></b><i class="term">Omf</i><b class="routine"><i class="routine">FmtManage</i></b><b>(&nbsp;)</b></li></ul>
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<dl class="margin">

<dd><font face="Helvetica, sans-serif" size="-1" class="sans">
<h5 class="HU"><i><a name="85369"><b class="routine"><i class="routine">load</i></b><i class="term">Omf</i><b class="routine"><i class="routine">FmtInit</i></b><b>(&nbsp;)</b> </a></i></h5>
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<dd><p class="Body"><a name="85370"> </a>This routine is the first entry point; it loads the correct relocation unit for the current target CPU.</p>
<dl class="margin">

<dd><pre class="Code2"><b><a name="85371">STATUS load<i class="textVariable">Omf</i>FmtInit (void)</a></b></pre>
</dl>

<dd><p class="Body"><a name="85372"> </a>The return value is:</p>
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<dl class="margin">

<dd><div class="Item"><a name="85373"> </a><b class="symbol_UC">STATUS</b> </div>
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<dd><div class="Indent"><a name="85374"> </a><b class="symbol_UC">OK</b> or <b class="symbol_UC">ERROR</b>. (See <i class="textVariable">installDir</i><b class="file">/host/include/host.h</b> for a description of error types and macros.)</div>
<br>
</dl>

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<h4 class="EntityTitle"><a name="85376"><font face="Helvetica, sans-serif" size="-1" class="sans">Example 3-2:&nbsp;&nbsp;<b class="routine"><i class="routine">load</i></b><i class="term">Omf</i><b class="routine"><i class="routine">FmtInit</i></b><b>(&nbsp;)</b> </font></a></h4>
<dl class="margin">

<dl class="margin">

<dd><pre class="Code"><b><a name="86657">/************************************************************************