c_copy.htm

mips架构的bootloader,99左右的版本 但源代码现在没人更新了

<title>The copy Command</title>
<h1>copy</h1>

<!--INDEX "copy command" -->

The copy command copies a specified number of bytes from one location 
in memory to another.<p>

</dl><h2>Format</h2><dl><dd>

The format of the copy command is:<p>

<pre>
copy [-f] from to size
</pre>

where:<p>

<table><tr><td>
from	</td><td>declares the source address location. 

</td></tr><tr><td>
to	</td><td>declares the target address location. 

</td></tr><tr><td>
size	</td><td>is the size of the block of memory to be copied. This quantity 
	is specified in bytes.
</td></tr><tr><td>
-f	</td><td>Specifies that the destination is flash memory.
</td></tr></table>

</dl><h2>Functional Description</h2><dl><dd>

The copy command replicates a specified number of bytes from one place 
in memory to another. <p>

The -f option is used when copying to flash memory. This requires that
the board supports writes to that address range, and that the flash
memories support sector erase.<p>

If to is less than from, copying is performed in ascending order starting at 
from. If from is less than to, copying is performed in descending order 
starting at from + size.<p>

When moving a data block down, the source data is copied from the
bottom of the block upwards: and when moving a data block up, the
source data is copied from the top of the block downwards. By this
technique, there is no risk of copying over data in overlapping block
move operations; as the data in the overlapping area is copied first.
However, if the -f option is specified, copying is always performed
in ascending address order.<p>

</dl><h2>Examples</h2><dl><dd>

<ul><li>
This example shows how to copy a block of memory, 8 Kbytes in
size, with a base address of 0x80020000, to another 8-Kbyte area
starting at the address 0x80060000.<p>

<pre>
PMON> copy 80020000 80060000 2000
</pre>

<li>
This example shows how to copy a block of memory, 4 Kbytes in
size, with a base address of 0x80020000, to a 4-Kbyte area of
flash memory starting at the address 0x80060000.<p>

<pre>
PMON> copy -f 80020000 bfc40000 1000
</pre>

<li>
This example shows how an application program may be copied into flash.
This example is applicable to PMON only.<p>

<pre>
pmcc -prom -crt0 -T 9fc40000 -D 80020000 -o bubble crt1.s bubble.c
PMON> load e03e0000
-- download bubble.rec
total = 146e
PMON> copy -f 80020000 bfc40000 1500
</pre>

Note:
<ol>
<li>The file crt1.s is exactly the same as lib/crt1.s, except that the
following lines have been added before the call to clrbss.<p>

<pre>
	li	a0,0x80020000
	jal	cpdata
</pre>


<li>The value e03e0000 is the difference between the link address 9fc40000
and the load address 80020000 (0x180020000-0x9fc40000=0xe03e0000).<p>

<li>The size argument for the copy command has been rounded up. The value
must be the total as reported by the load command plus at least 32.<p>
</ol>

To run the application, type,<p>
<pre>
PMON> g 9fc40000
</pre>
</ul>
</dl><h2>Files</h2><dl><dd>
The copy command is located in <a href="../mon/copy.c">mon/copy.c</a>.

</dl><h2>See Also</h2><dl><dd>
<a href="c_compare.htm">compare command</a>

</dl><p><hr>
<b>Navigation:</b> 
<a href="index.htm">Document Home</a> | 
<a href="doctoc.htm">Document Contents</a> | 
<a href="docindex.htm">Document Index</a> <p>