c_m.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 m Command</title>
<h1>m</h1>

<!--INDEX "m command" "modify memory" -->

The m command displays and modifies memory. <p>

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

The format for the m command is:<p>

<pre>
m [-bhw] [adr [hexval|-s str]..]
</pre>

where:<p>

<table><tr><td>
-b	</td><td>is a flag signifying that byte accesses are to be used.
</td></tr><tr><td>
-h	</td><td>is a flag signifying that halfword accesses are to be used.
</td></tr><tr><td>
-w	</td><td>is a flag signifying that word accesses are to be used.

</td></tr><tr><td>
adr	</td><td>is the memory address to display or modify without entering 
interactive mode.

</td></tr><tr><td>
hexval	</td><td>is the value to insert at the specified address.

</td></tr><tr><td>
-s	</td><td>is a flag signifying that the following parameter is a string 
value.

</td></tr><tr><td>
str	</td><td>is a string value to copy to the specified address.

</td></tr><tr><td>
<CR>	</td><td>enters interactive mode.

</td></tr><tr><td>
=	</td><td>in interactive mode, reads current address again.

</td></tr><tr><td>
^|-	</td><td>in interactive mode, moves back one word.

</td></tr><tr><td>
.	</td><td>exits interactive mode.
</td></tr></table><p>

Entering no values with this command causes the command to operate in 
interactive mode.<p>

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

This command can display and then modify memory locations
interactively. This command can also set memory to a specified value
directly.<p>

If invoked with one or more values following the address, the command is 
executed immediately, without entering the interactive mode.<p>

If the command is invoked without a value, the command enters the
interactive memory mode. In interactive memory mode, the user enters a
command at the cursor. The interactive memory mode first displays the
address and its current value. Interactive memory mode then lets the
user select one of the commands listed in the following table.<p>

If the -s option is specified, the <a href="mondef.htm">Monitor</a>
displays the memory contents as an ASCII string. A multiple-word string
may be specified by enclosing the multiple-word string in quotation
marks.<p>

Examples illustrating the use of the m command follow.<p>

<pre>
PMON> m a0020000	Display memory at address in interactive mode.
a0020000 00 _ 	User can enter command at cursor (_).

PMON> m a0020000 1 2 3 4	Set address 0xa0020000 to 1, address 
				0xa0020001 to 2, etc., in noninteractive mode.

PMON> m a0020000	Display memory at 0xa0020000.
a0020000 01 CR 
a0020001 02 CR 
a0020002 03 CR 
a0020003 04 .

PMON> m a0020000 22	Set address 0xa0020000 to 0x22.
PMON> m a0020000 	Display memory at 0xa0020000.
a0020000 22 44 
a0020001 00 <CR> 
a0020002 00 55 
a0020003 00 66
a0020004 00 ^ 
a0020003 66 <CR>
a0020004 00 .

PMON> m 80020000 -s even	Set memory starting at 0x80020000 to 
				the string "even."
	

PMON> m 80030100 -s "LSI Logic"
Set memory starting at 0x80030100 to 
the multiple-word string "LSI Logic."
</pre>

</dl><h2>Files</h2><dl><dd>
The m command is located in <a href="../mon/modify.c">mon/modify.c</a>.

</dl><h2>See Also</h2><dl><dd>
<a href="c_fill.htm">fill command</a>,
<a href="c_l.htm">l command</a>,
<a href="c_d.htm">d command</a>,
and <a href="c_dump.htm">dump command</a>.

</dl><p><hr>
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