setting_up_a_dhcp_server.html

ADI 公司blackfin系列的用户使用文挡。

</p>
<pre class="code">
bash# rcdhcpd stop
</pre>

<p>
Alternately the DHCP server can be stopped by de-selecting <strong>Enable DHCP Server at Boot Time</strong> through YaST2.  The status of the DHCP server can be viewed by typing the following command:
</p>
<pre class="code">
bash# rcdhcpd status
</pre>

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<h3><a name="windows_instructions" id="windows_instructions">Windows Instructions</a></h3>
<div class="level3">

<p>
There are several DHCP server programs available for the Windows platform.  The setup instructions in this section are for the program DHCP Turbo.  DHCP Turbo is available free of charge from <a href="http://www.weird-solutions.com/" class="urlextern" title="http://www.weird-solutions.com/"  rel="nofollow">http://www.weird-solutions.com</a>.  The setup procedure for other DHCP server programs will differ.
</p>

<p>
First, download the installer program for DHCP Turbo and run it.  Follow the instructions given to install DHCP Turbo, select a full installation.  When asked if you want DHCP Turbo to start every time the computer is booted it is recommenced that you select <strong>NO</strong>.  This will help prevent inadvertently running DHCP Turbo when your computer is connected to a network which already has functioning a DHCP server.  Once installation is complete start DHCP Turbo.  The DHCP Turbo main window should now be displayed:
</p>

<p>
<a href="media/dhcp8.png" class="media" target="_blank" title="dhcp8.png"><img src="media/dhcp8.png" class="media" alt="" /></a>
</p>

<p>
In the <strong>Servers</strong> sidebar select <strong>localhost</strong>.  Under the <strong>Tools</strong> menu select <strong>Control Service</strong>.  The Control Service dialog should now be displayed:
</p>

<p>
<a href="media/dhcp9.png" class="media" target="_blank" title="dhcp9.png"><img src="media/dhcp9.png" class="media" alt="" /></a>
</p>

<p>
If the message says  &ldquo;<em><strong>DHCP Turbo is not running on localhost</strong></em>&rdquo; ensure that your computer is disconnected from any network with an active DHCP server then click <strong>Start</strong> then click <strong>OK</strong>.
</p>

<p>
If the message says &ldquo;<em><strong>DHCP Turbo is running on localhost</strong></em>&rdquo; simply click <strong>OK</strong>.
</p>

<p>
Back at the main window:
</p>

<p>
<a href="media/dhcp8.png" class="media" target="_blank" title="dhcp8.png"><img src="media/dhcp8.png" class="media" alt="" /></a>
</p>

<p>
Double Click on <strong>localhost</strong> in the <strong>Servers</strong> sidebar.
</p>

<p>
The login dialog should now be displayed:
</p>

<p>
<a href="media/dhcp10.png" class="media" target="_blank" title="dhcp10.png"><img src="media/dhcp10.png" class="media" alt="" /></a>
</p>

<p>
Leave the <strong>Password</strong> field <strong>blank</strong> and click on <strong>Login</strong>
</p>

<p>
Back at the main window:
</p>

<p>
<a href="media/dhcp11.png" class="media" target="_blank" title="dhcp11.png"><img src="media/dhcp11.png" class="media" alt="" /></a>
</p>

<p>
Right click on <strong>Scopes</strong> under <strong>localhost</strong>.
</p>

<p>
Select <strong>New Scope</strong>.
</p>

<p>
The New Scope dialog should now be displayed:
</p>

<p>
<a href="media/dhcp12.png" class="media" target="_blank" title="dhcp12.png"><img src="media/dhcp12.png" class="media" alt="" /></a>
</p>

<p>
Enter a name for the scope in the <strong>Name</strong> field.
</p>

<p>
Enter a valid range of IP addresses that the server can assign by entering a valid <strong>Start Address</strong>, <strong>End Address</strong>, and <strong>Subnet Mask</strong>.
</p>

<p>
Click <strong>OK</strong>.
</p>

<p>
Next the name of the boot file must be specified:
</p>

<p>
<a href="media/dhcp13.png" class="media" target="_blank" title="dhcp13.png"><img src="media/dhcp13.png" class="media" alt="" /></a>
</p>

<p>
Expand the <strong>Scopes</strong> tree in the sidebar and select the scope that was just created.
</p>

<p>
Click on the <strong>Policies</strong> tab.
</p>

<p>
Right click on the policies window.
</p>

<p>
Select <strong>New Option</strong>.
</p>

<p>
The Option Selector window should now be displayed:
</p>

<p>
<a href="media/dhcp14.png" class="media" target="_blank" title="dhcp14.png"><img src="media/dhcp14.png" class="media" alt="" /></a>
</p>

<p>
Select <strong>Boot file</strong> and click <strong>OK</strong>.
</p>

<p>
The Boot file dialog should now be displayed:
</p>

<p>
<a href="media/dhcp15.png" class="media" target="_blank" title="dhcp15.png"><img src="media/dhcp15.png" class="media" alt="" /></a>
</p>

<p>
Enter <strong>linux</strong> for the value of the boot file option.
</p>

<p>
(Assuming linux is the name of the kernel memory image to be loaded via TFTP)
</p>

<p>
Click <strong>OK</strong>.
</p>

<p>
Finally to save these changes go to the <strong>File</strong> menu and select <strong>Save</strong>.
</p>

<p>
The DHCP Turbo server should now be able to provide U-Boot with all the information it needs to boot the target system via DHCP boot.  Before reconnecting your computer to a network with an active DHCP server ensure that you stop DHCP Turbo by selecting <strong>Control Service</strong> under the <strong>Tools</strong> menu and clicking on <strong>Stop</strong>.
</p>

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<h3><a name="using_u-boot_with_dhcp" id="using_u-boot_with_dhcp">Using U-Boot With DHCP</a></h3>
<div class="level3">

<p>
To boot uClinux via DHCP open a terminal session in Minicom, HyperTerminal, or another terminal program.  See <a href="terminal_programs.html" class="wikilink1" title="terminal_programs.html">Terminal Programs</a> on page  for more information on setting up a terminal program to communicate with uClinux/U-Boot.  Reset the target system and hit any key before the autoboot countdown finishes.  You should now be at the U-Boot command prompt.  Enter the command:
</p>
<pre class="code">
BOOT&gt; print
</pre>

<p>
U-Boot&rsquo;s environment variables should now be displayed and will look something like the following: 
</p>
<pre class="code">
bootcmd=run dhcp_boot
bootdelay=30 
baudrate=57600
loads_echo=1 
ipaddr=192.168.0.95
serverip=192.168.0.32
gatewayip=192.168.0.2 
netmask=255.255.255.0 
hostname=BF533
netdev=eth0
tftp_boot=tftp 0x1000000 linux;bootelf 0x1000000;echo
dhcp_boot=dhcp;bootelf 0x1000000;echo
serial_boot=loadb;bootelf 0x1000000;echo
stdin=serial
stdout=serial
stderr=serial 
</pre>

<p>
Ensure the following environment variables are set: 
</p>
<pre class="code">
BOOT&gt; dhcp_boot=dhcp;bootelf 0x1000000;echo
BOOT&gt; bootcmd=run dhcp_boot
</pre>

<p>
If these environment variables are not set use the U-Boot command <strong>set &lt;variable&gt; &lt;value&gt;</strong> to set them.  The U-Boot command <strong>save</strong> can then be used to save the environment variables to flash memory.
</p>

<p>
 
</p>

<p>
<code>set tftp_boot &lsquo;tftp  0&times;1000000 linux;bootelf 0&times;1000000;echo</code>&rsquo; 
</p>

<p>
On restart, after the autoboot countdown timer finishes, U-Boot should now obtain an IP address and a memory image filename from the DHCP server and a load the image via TFTP.  Alternately a DHCP boot can be initiated from the U-Boot command line by entering the following commands at the U-Boot prompt: 
</p>
<pre class="code">
BOOT&gt; dhcp
BOOT&gt; bootelf 0x1000000
</pre>

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