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<h1>U-boot extensions in 2009.01-rc1</h1>
</div>
2009-03-02 09:34:20 +01:00
<p><a href="http://buildroot.net/">U-Boot</a>
usage and documentation by Ulf Samuelsson.
</p>
<ul>
<li><a href="#about">About U-Boot</a></li>
<li><a href="#at91rm9200dk">Board Support for AT91RM9200DK</a></li>
<li><a href="#at91rm9200ek">Board Support for AT91RM9200EK</a></li>
<li><a href="#at91sam9g20ek">Board Support for AT91SAM9G20EK</a></li>
<li><a href="#Minicom extensions">X-Modem/Raw extensions to minicom</a></li>
<li><a href="#cmd_factory">New Command: factory</a></li>
<li><a href="#cmd_os">New Command: os</a></li>
<li><a href="#cmd_fs">New Command: fs</a></li>
<li><a href="#cmd_setargs">New Command: setargs</a></li>
<li><a href="#cmd_led">New Command: led</a></li>
<li><a href="#cmd_mux">New Command: mux</a></li>
<li><a href="#cmd_ethinit">New Command: ethinit</a></li>
<li><a href="#environment">Special environment variables</a></li>
</ul>
<h2><a name="about" id="about"></a>About U-boot</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
U-Boot is an open source bootloader ported to a multitude of processors.
See (<a href="http://www.denx.de/wiki/U-Boot/WebHome">U-Boot Home</a>)
for documentation for vanilla U-Boot. This document only describes
changes compared to the vanilla u-boot.
</p>
<h2><a name="at91rm9200dk" id="at91rm9200dk"></a>Board support for at91rm9200dk</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
"at91rm9200dk" is updated to use a linux like API for gpio.
A new target "at91rm9200dk_df" is defined to support boot from dataflash.
</p>
<h2><a name="at91rm9200ek" id="at91rm9200ek"></a>Board support for at91rm9200ek</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
The "at91rm9200ek" BSP supports booting from a parallel flash.
The "at91rm9200df" BSP supports a generic target booting from dataflash.
</p>
<h2><a name="#at91sam9g20ek" id="#at91sam9g20ek"></a>Board support for at91sam9g20ek</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
The "at91sam9g20ek" target with dataflash(card) and NAND boot support.
</p>
<h2><a name="minicom_extensions" id="minicom_extensions"></a>Minicom extensions </h2>
<a href="#top"><small>[TOP]</small></a>
<p>
"sx-at91" is a reliable X-Modem application allowing download to the at91rm9200
based board
</p>
<p>
"raw-at91" is a download application which will download binary data using minicom.
Typically used to download an environment script.
</p>
<h2><a name="cmd_factory" id="cmd_factory"></a>New command: factory</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
<h3><code>factory</code></h3>
</p>
<p>
"factory" will set a selected set of environment variables
back to the compile time default. The following will give some
hints on capabilities, but is not yet complete.
</p>
<p>
It will generate a set of scripts which will facilitate downloading
the kernel and root file system using tftp and will also
add commands to store into and retrieve from flash
</p>
<h2><a name="cmd_os" id="cmd_os"></a>New command: os</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
<h3><code>os<code></h3>
</p>
<p>
"os" computes a new name for the linux kernel
</p>
<h2><a name="cmd_fs" id="cmd_fs"></a>New command: fs</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
<h3><code>fs<code></h3>
</p>
<p>
"fs" computes a new name for the file system
</p>
<h2><a name="cmd_setargs" id="cmd_setargs"></a>New command: setargs</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
<h3><code>setargs<code></h3>
</p>
<p>
"setargs" will create new bootcmd/bootargs combination from
kernel name, filesystem name, and rootfs type.
</p>
<h2><a name="cmd_led" id="cmd_led"></a>New command: led</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
<h3><code>led [green | yellow | red | all ] [ on | off ]<code></h3>
</p>
<p>
"led" will turn on or off the specified (coloured) led
</p>
<h2><a name="cmd_mux" id="cmd_mux"></a>New command: mux</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
<h3><code>mux [spi | mmc ]<code></h3>
</p>
<p>
"mux" will select how to use the flash card connector on the
at91rm9200dk or at91rm9200ek
</p>
<h2><a name="cmd_ethinit" id="cmd_ethinit"></a>New command: ethinit</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
<h3><code>ethinit<code></h3>
</p>
<p>
"ethinit" can be used to delay the boot of linux, until a valid network
connection has been established. This is useful if the machine is NFS mounting
the root file system and both this machine and the NFS server are powering up
simultaneously. The NFS server could take a lot longer to boot, and waiting
for this to boot may be neccessary for proper operation.
</p>
<h2><a name="environment" id="environment"></a>Special environment variables</h2>
<a href="#top"><small>[TOP]</small></a>
<p>
<h3><code>rd<code></h3>
</p>
<p>
rd contains the name of the current root file system
It is autmatically generated from <bold>ver</bold> and <bold>rd-1</bold>, <bold>rd-2</bold> etc.
The "fs-date" is added at the end.
</p>
<p>
<h3><code>ver<code></h3>
</p>
<p>
You can handle a number of different root fs by defining <code>ver</code>.
When running <code>fs</code> rd will be assigned from one of:
<ul><code>rd-1, rd2, rd-3 ...<code></ul>
</p>
<p>
By defining <code>ver</code> to a number you will
select the appropriate disk name
</p>
<p>
<h3><code>fs-date<code></h3>
</p>
<p>
"date" part of the root file system name
</p>
<p>
<h3><code>linux<code></h3>
</p>
<p>
linux contains the name of the current kernel.
</p>
<p>
It is generated from several environment variables when <code>os</code> is run
</p>
<p>
A typical name would be "at91sam9263ek-linux-2.6.28-20090105.gz"
</p>
<p>
<h3><code>hostname<code></h3>
</p>
<p>
"name" part of the kernel file name
</p>
<p>
<h3><code>kernel-version<code></h3>
</p>
<p>
"version" part of the kernel file name
</p>
<p>
<h3><code>kernel-date<code></h3>
</p>
<p>
"date" part of the kernel file name
</p>
<p>
<h3><code>fstype [ ram | flash ]<code></h3>
<p>
You can have several file system types.
bootargs is created depending on fstype..
</p>
<a href="#top"><small>[TOP]</small></a>
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