vmlib.html

Vxworks API操作系统和驱动程序设计API。压缩的HTML文件

<p><strong>vmContextDelete(&nbsp;)</strong> - delete a virtual memory context (VxVMI Option)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS vmContextDelete
    (
    VM_CONTEXT_ID context
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine deallocates the underlying translation table associated with
a virtual memory context.  It does not free the physical memory already
mapped into the virtual memory space.
<p>
This routine should not be called from interrupt level.
<p>
</blockquote><h4>AVAILABILITY</h4><blockquote><p>
This routine is distributed as a component of the unbundled virtual memory
support option, VxVMI.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK, or ERROR if <i>context</i> is not a valid context descriptor or
if an error occurs deleting the translation table.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./vmLib.html#top">vmLib</a></b>

<hr>
<a name="vmStateSet"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>vmStateSet(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>vmStateSet(&nbsp;)</strong> - change the state of a block of virtual memory (VxVMI Option)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS vmStateSet
    (
    VM_CONTEXT_ID context,    /* context - NULL == currentContext */
    void *        pVirtual,   /* virtual address to modify state of */
    int           len,        /* len of virtual space to modify state of */
    UINT          stateMask,  /* state mask */
    UINT          state       /* state */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine changes the state of a block of virtual memory.  Each page
of virtual memory has at least three elements of state information:
validity, writability, and cacheability.  Specific architectures may
define additional state information; see <b>vmLib.h</b> for additional
architecture-specific states.  Memory accesses to a page marked as
invalid will result in an exception.  Pages may be invalidated to prevent
them from being corrupted by invalid references.  Pages may be defined as
read-only or writable, depending on the state of the writable bits.
Memory accesses to pages marked as not-cacheable will always result in a
memory cycle, bypassing the cache.  This is useful for multiprocessing,
multiple bus masters, and hardware control registers.
<p>
The following states are provided and may be or'ed together in the 
state parameter:  
<p>
<table>
<tr valign=top>
<td align=left><b>VM_STATE_VALID</b>     </td><td align=left> <b>VM_STATE_VALID_NOT</b>     </td><td align=left> valid/invalid</tr>
<tr valign=top>
<td align=left><b>VM_STATE_WRITABLE</b>  </td><td align=left> <b>VM_STATE_WRITABLE_NOT</b>  </td><td align=left> writable/write-protected</tr>
<tr valign=top>
<td align=left><b>VM_STATE_CACHEABLE</b> </td><td align=left> <b>VM_STATE_CACHEABLE_NOT</b> </td><td align=left> cacheable/not-cacheable</tr>
<tr valign=top>
<td align=left></tr>
</tr>

</table>

Additionally, the following masks are provided so that only specific
states may be set.  These may be or'ed together in the <b>stateMask</b> parameter. 
<p>
&nbsp;<b>VM_STATE_MASK_VALID</b><br>
&nbsp;<b>VM_STATE_MASK_WRITABLE</b><br>
&nbsp;<b>VM_STATE_MASK_CACHEABLE</b>
<p>
If <i>context</i> is specified as NULL, the current context is used.
<p>
This routine is callable from interrupt level.
<p>
</blockquote><h4>AVAILABILITY</h4><blockquote><p>
This routine is distributed as a component of the unbundled virtual memory
support option, VxVMI.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK or, ERROR if the validation fails, <i>pVirtual</i> is not on a page
boundary, <i>len</i> is not a multiple of page size, or the
architecture-dependent state set fails for the specified virtual address.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<p>
<b>S_vmLib_NOT_PAGE_ALIGNED</b>,
<b>S_vmLib_BAD_STATE_PARAM</b>,
<b>S_vmLib_BAD_MASK_PARAM</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./vmLib.html#top">vmLib</a></b>

<hr>
<a name="vmStateGet"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>vmStateGet(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>vmStateGet(&nbsp;)</strong> - get the state of a page of virtual memory (VxVMI Option)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS vmStateGet
    (
    VM_CONTEXT_ID context,    /* context - NULL == currentContext */
    void *        pPageAddr,  /* virtual page addr */
    UINT *        pState      /* where to return state */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine extracts state bits with the following masks: 
<p>
&nbsp;<b>VM_STATE_MASK_VALID</b><br>
&nbsp;<b>VM_STATE_MASK_WRITABLE</b><br>
&nbsp;<b>VM_STATE_MASK_CACHEABLE</b>
<p>
Individual states may be identified with the following constants:
<p>
<table>
<tr valign=top>
<td align=left><b>VM_STATE_VALID</b>    </td><td align=left> <b>VM_STATE_VALID_NOT</b>     </td><td align=left> valid/invalid</tr>
<tr valign=top>
<td align=left><b>VM_STATE_WRITABLE</b> </td><td align=left> <b>VM_STATE_WRITABLE_NOT</b>  </td><td align=left> writable/write-protected</tr>
<tr valign=top>
<td align=left><b>VM_STATE_CACHEABLE</b></td><td align=left> <b>VM_STATE_CACHEABLE_NOT</b> </td><td align=left> cacheable/not-cacheable</tr>
<tr valign=top>
<td align=left></tr>
</tr>

</table>

For example, to see if a page is writable, the following code would be used:
<p>
<pre>    vmStateGet (vmContext, pageAddr, &amp;state);
    if ((state &amp; VM_STATE_MASK_WRITABLE) &amp; VM_STATE_WRITABLE)
       ...
</pre>

If <i>context</i> is specified as NULL, the current virtual memory context 
is used.
<p>
This routine is callable from interrupt level.
<p>
</blockquote><h4>AVAILABILITY</h4><blockquote><p>
This routine is distributed as a component of the unbundled virtual memory
support option, VxVMI.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK, or ERROR if <i>pageAddr</i> is not on a page boundary, the
validity check fails, or the architecture-dependent state get fails for
the specified virtual address.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_vmLib_NOT_PAGE_ALIGNED</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./vmLib.html#top">vmLib</a></b>

<hr>
<a name="vmMap"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>vmMap(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>vmMap(&nbsp;)</strong> - map physical space into virtual space (VxVMI Option)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS vmMap
    (
    VM_CONTEXT_ID context,      /* context - NULL == currentContext */
    void *        virtualAddr,  /* virtual address */
    void *        physicalAddr, /* physical address */
    UINT          len           /* len of virtual and physical spaces */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine maps physical pages into a contiguous block of virtual
memory.  <i>virtualAddr</i> and <i>physicalAddr</i> must be on page boundaries, and
<i>len</i> must be evenly divisible by the page size.  After the call to
<b><a href="./vmLib.html#vmMap">vmMap</a>(&nbsp;)</b>, the state of all pages in the the newly mapped virtual memory is
valid, writable, and cacheable.
<p>
The <b><a href="./vmLib.html#vmMap">vmMap</a>(&nbsp;)</b> routine can fail if the specified virtual address space
conflicts with the translation tables of the global virtual memory space.
The global virtual address space is architecture-dependent and is
initialized at boot time with calls to <b><a href="./vmLib.html#vmGlobalMap">vmGlobalMap</a>(&nbsp;)</b> by
<b><a href="./vmLib.html#vmGlobalMapInit">vmGlobalMapInit</a>(&nbsp;)</b>.  If a conflict results, <b>errno</b> is set to
<b>S_vmLib_ADDR_IN_GLOBAL_SPACE</b>.  To avoid this conflict, use
<b><a href="./vmLib.html#vmGlobalInfoGet">vmGlobalInfoGet</a>(&nbsp;)</b> to ascertain which portions of the virtual address space
are reserved for the global virtual address space.  If <i>context</i> is
specified as NULL, the current virtual memory context is used.
<p>
This routine should not be called from interrupt level.
<p>
</blockquote><h4>AVAILABILITY</h4><blockquote><p>
This routine is distributed as a component of the unbundled virtual memory
support option, VxVMI.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK, or ERROR if <i>virtualAddr</i> or <i>physicalAddr</i> are not 
on page boundaries, <i>len</i> is not a multiple of the page size, 
the validation fails, or the mapping fails.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<p>
<b>S_vmLib_NOT_PAGE_ALIGNED</b>,
<b>S_vmLib_ADDR_IN_GLOBAL_SPACE</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./vmLib.html#top">vmLib</a></b>

<hr>
<a name="vmGlobalMap"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>vmGlobalMap(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>vmGlobalMap(&nbsp;)</strong> - map physical pages to virtual space in shared global virtual memory (VxVMI Option)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS vmGlobalMap
    (
    void * virtualAddr,       /* virtual address */
    void * physicalAddr,      /* physical address */
    UINT   len                /* len of virtual and physical spaces */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine maps physical pages to virtual space that is shared by all
virtual memory contexts.  Calls to <b><a href="./vmLib.html#vmGlobalMap">vmGlobalMap</a>(&nbsp;)</b> should be made before any
virtual memory contexts are created to insure that the shared global
mappings are included in all virtual memory contexts.  Mappings created
with <b><a href="./vmLib.html#vmGlobalMap">vmGlobalMap</a>(&nbsp;)</b> after virtual memory contexts are created are not
guaranteed to appear in all virtual memory contexts.  After the call to
<b><a href="./vmLib.html#vmGlobalMap">vmGlobalMap</a>(&nbsp;)</b>, the state of all pages in the the newly mapped virtual
memory is unspecified and must be set with a call to <b><a href="./vmLib.html#vmStateSet">vmStateSet</a>(&nbsp;)</b>, once
the initial virtual memory context is created.
<p>
This routine should not be called from interrupt level.
<p>
</blockquote><h4>AVAILABILITY</h4><blockquote><p>
This routine is distributed as a component of the unbundled virtual memory
support option, VxVMI.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK, or ERROR if <i>virtualAddr</i> or <i>physicalAddr</i> are not 
on page boundaries, <i>len</i> is not a multiple of the page size, 
or the mapping fails.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>