paddcmd.htm

mips架构的bootloader,99左右的版本 但源代码现在没人更新了

		<title>Adding PMON Commands</title>
		<h1 align=center>Adding PMON Commands</h1>

<!--INDEX "Adding PMON Commands" mycmd -->

Adding commands to PMON is very simple. In this example, we wish to
add a command called mycmd. This command simply identifies
itself and prints out a list of its arguments. The function is placed
in a file called mycmd.c in the pmon subdirectory. Notice that it is
called with an argc/argv argument list in exactly the same way as
a normal C program is called. As with UNIX, the name of the 
command is located in argv[0].<p>

<pre>
<b>pmon/mycmd.c</b>

	Optdesc mycmd_opts[] = {
		{"","My Command"},
		{0}};

	mycmd(argc,argv)
	int argc;
	char *argv[];
	{
	int i;

	printf("This is my command. Arguments were: ");
	for (i=1;i&lt;argc;i++) printf("%s ",argv[i]);
	printf("\n");
	}


</pre>

Note that you can also list any options that your new command accepts, to
the mycmd_opts array. The first field can contain the list of options. 
Additional lines would explain those options. For example,<p>

<pre>
	Optdesc mycmd_opts[] = {
		{"[-fl]","My Command"},
		{"-f","Find bug"},
		{"-l","Lose bug"},
		{0}};
</pre>

The name of this function must now be installed in the table of
commands. The easiest way to do this is by using addCmdRec(). You
can place this call almost anywhere, but perhaps the best place is
in the CPU-specific high-init init code, eg. c4101.c. There is already
a list of commands in this file, you just need to all yours to the list.<p>

<pre>
	CmdRec cmds[] = {
		{"cache",mycmd_opts,mycmd},
		.....
		{0}};
</pre>


Finally, the new module must be added to the list used by the Makefile.<p>

<pre>
<b>pmon/files.mk</b>

	CFILES = sonic.c main.c commands.c dis.c hist.c regs.c sym.c \
		 set.c stty.c more.c memtst.c go.c load.c debug.c \
		 cmdtable.c sbrk.c mycmd.c
</pre>

To support arguments that can be complex expressions, convert the
argument from ascii to binary using the function get_rsa(). This
function has the prototype:

<pre>
	int get_rsa(unsigned long *value, char *source);
</pre>

Where:<p>

	<dl><dd><table><tr><td>
	<var>source</var> </td><td>is the input ascii string.
	</td></tr><tr><td>
	<var>value</var> </td><td>is the place where the binary value is
	to be written.
	</td></tr><tr><td colspan=2>
	The return value is 1 if the conversion was successful, otherwise
	it is zero. get_rsa() prints its own messages if the conversion
	was unsuccessful.
	</td></tr></table></dl><p>

Example:<p>
<pre>
	if(!get_rsa(&adr,av[i])) return;
</pre>

Once the files havebeen modified, you need to rebuild PMON and <a
href="mkroms.htm">make</a> new <a href="romdef.htm">ROMs</a>.<p>


</dl><p><hr>
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