View source for U-Boot - i.MX8

<p>// </p>
<p>This section will provide all the details about the U-Boot bootloader for i.MX8 platforms, from the source code location to the flashing procedure.</p>
<h3> </h3>
<h3> </h3>
<h3>Where is U-Boot source code?</h3>
<p>Just like most of our source code, it is located on GitHub:</p>
<ul>
<li>[https://github.com/boundarydevices/u-boot-imx6/tree/boundary-v2018.07 boundary-v2018.07]</li>
</ul>
<h3 id="contentlink0">Where to get the latest binary for my platform?</h3>
<p>Our build server automatically generates and uploads all the latest binaries to this address:</p>
<ul>
<li>[http://linode.boundarydevices.com/u-boot-images http://linode.boundarydevices.com/u-boot-images]</li>
</ul>
<p>The [http://linode.boundarydevices.com/u-boot-images/README README] file contains the exact commit ID of this build images.</p>
<p>Also, the up-to-date [http://linode.boundarydevices.com/u-boot-images/upgrade.scr upgrade.scr] U-Boot script is included so you can copy all the files directly to the root of your media storage.</p>
<h3 id="contentlink1">How to flash U-Boot?</h3>
<p>Just like for our previous versions, we provide a simplified upgrade script that does it for you.</p>
<p>All you need to do is to copy the images (<code>u-boot.&lt;<tt>uboot_defconfig</tt>&gt;</code>, <code>upgrade.scr</code>) to either eMMC or USB drive and issue the following command:</p>
<pre class="brush: shell">=&gt; run upgradeu</pre>
<p>This will run the <code>upgrade.scr</code> script and look for a file <tt>u-boot.{uboot_defconfig}</tt> and burn it.</p>
<p>You can have a look at the <code>upgrade.txt</code> file content to understand the flashing procedure:</p>
<ul>
<li>[https://github.com/boundarydevices/u-boot-imx6/blob/boundary-v2018.07/board/boundary/bootscripts/upgrade.txt#L33 board/boundary/bootscripts/upgrade.txt#L33]</li>
</ul>
<p><strong>NB</strong>: U-Boot resides in "<em>Boot Partition 1</em>", not in the main data area.</p>
<p>See [https://pejmank3.sg-host.com/attachments/Victo_Tsai-1-.pdf this JEDEC presentation] to learn about the different partitions available.</p>
<p id="contentlink2"> </p>
<h3> </h3>
<h3> </h3>
<h3> </h3>
<h3>How to build U-Boot?</h3>
<p>Please read the following page about building the latest U-Boot:</p>
<p>[https://boundarydevices.com/u-boot-v2018-07/ https://boundarydevices.com/u-boot-v2018-07/]</p>
<pre class="brush: shell"> </pre>
<h3> </h3>
<h3 id="contentlink3">How can I configure the display?</h3>
<p>Since we offer several display options to our customers, we offer custom method to configure the display from U-Boot.</p>
<p>Just like it was explained in our [https://boundarydevices.com/display-configuration-u-boot/ Display configuration from U-Boot] post, you can set an environment variable to specify which display you plan on using.</p>
<p>This mechanism now also works with MIPI displays! Here is an example on how to set up the board to use our [https://boundarydevices.com/product/bd080mcc1-display/ BD080MCC1] display.</p>
<pre class="brush: shell">=&gt; setenv fb_mipi ltk080a60a004t
=&gt; savee
=&gt; reset</pre>
<p id="contentlink4"> </p>
<h3> </h3>
<h3> </h3>
<h3> </h3>
<h3>Oops, I bricked the device, how do I recover?</h3>
<p>Just like our previous [https://boundarydevices.com/unbricking-nitrogen6x-sabre-lite-i-mx6-board/ unbricking procedure], this platform allows to boot from USB using the Serial Downloader Protocol.</p>
<p>First you'll need to connect your board's USB OTG port to your PC's USP port. You must use <span style="color: #00ff00">USB2.0</span> cable and <span style="color: #ff0000">not USB3.0</span> cable</p>
[caption id="attachment_35892" align="alignleft" width="322"][https://pejmank3.sg-host.com/images/d/dd/USB2.0-OTG-e1575666246252.jpg 
[[File:USB2.0-OTG-e1575666246252.jpg]]] <strong>USB2.0 OTG cable</strong>[/caption] [caption id="attachment_35893" align="aligncenter" width="323"][https://pejmank3.sg-host.com/images/4/4c/USB3.0-OTG-e1575666520478.jpg 
[[File:USB3.0-OTG-e1575666520478.jpg]]] <strong>USB3.0 OTG cable</strong>[/caption]
<p> </p>
<p>For example: [https://www.amazon.com/AmazonBasics-Male-Micro-Cable-Black/dp/B07232M876 https://www.amazon.com/AmazonBasics-Male-Micro-Cable-Black/dp/B07232M876]</p>
<p>Then you'll need to push SW1 DIP switch to ON position</p>
[caption id="attachment_35890" align="alignleft" width="330"][https://pejmank3.sg-host.com/attachments/DSC_0640-3.jpg 
[[File:DSC_0640-3-scaled-1.jpg]]] <strong>SW1 position on Nitrogen8MQ</strong>[/caption] [caption id="attachment_35891" align="aligncenter" width="331"][https://pejmank3.sg-host.com/attachments/DSC_0641-3.jpg 
[[File:DSC_0641-3-scaled-1.jpg]]] <strong>SW1 position on Nitrogen8M Mini</strong>[/caption]
<p> </p>
<p>Then you should be able to see the platform appears as a USB HID device on your linux PC's :</p>
<pre class="brush: shell">~$ lsusb | grep NXP
Bus 001 Device 010: ID 1fc9:012b NXP Semiconductors i.MX 8M...
or
Bus 001 Device 010: ID 1fc9:0134 NXP Semiconductors i.MX 8M Mini...</pre>
<p>Finally, download our imx-usb-loader tool and run it:</p>
<pre class="brush: shell">~$ sudo apt install libusb-1.0-0-dev pkg-config
~$ git clone git://github.com/boundarydevices/imx_usb_loader
~$ cd imx_usb_loader/
~/imx_usb_loader$ make
...
~/imx_usb_loader$ ./imx_usb
</pre>
<p>Note that we recommend you have a look at the <code>mx8mq_usb_work.conf</code> or <code>mx8mm_usb_work.conf</code> file (depending on your board type) since it includes hardcoded paths ( ../u-boot-imx6/flash.bin ) which might differ on your machine.</p>
<p>Also, the above instructions require your user to have permissions to access the USB device.</p>
<p>Although adding <code>sudo</code> might solve this "issue", we highly recommend you use a [https://wiki.archlinux.org/index.php/udev udev rule] instead.</p>
<p>Finally, in order to recover your platform, the <code>imx_usb</code> tool requires to have all binaries separately. That means it requires you to build your own version of U-Boot binaries by following the procedure above.</p>
<p>After you finished recovering your U-Boot, don't forget to set SW1 switch back to OFF on the board.</p>
<h3>How to erase U-Boot environment?</h3>
<p>In order to force the use of the default environment variables and save this instead.</p>
<pre class="brush: shell">=&gt; env default -a
=&gt; savee</pre>
<h3>How to enable secure booting with U-Boot?</h3>
<p>All the i.MX processors embed some security engine which allows to sign/encrypt the boot-loader.</p>
<p>The article below details the engine architecture and how to enable/use it:</p>
<ul>
<li>[https://boundarydevices.com/high-assurance-boot-hab-dummies/ High Assurance Boot for dummies]</li>
</ul>
<h3>How can I boot from network?</h3>
<p>The usual setup is to use a [https://en.wikipedia.org/wiki/Trivial_File_Transfer_Protocol TFTP] server to load the kernel, device tree and then share the rootfs from Host PC over [https://en.wikipedia.org/wiki/Network_File_System NFS].</p>
<p>So you need to install both TFTP and NFS servers on your host PC. To do so, please follow this article:</p>
<ul>
<li>[https://elinux.org/TFTP_Boot_and_NFS_Root_Filesystems eLinux - TFTP Boot and NFS Root Filesystem]</li>
</ul>
<p>Once this setup is done, we tried to simplify your life since the board only requires two variables to boot from network:</p>
<ol>
<li>The TFTP/NFS server IP</li>
<li>The NFS rootfs path</li>
</ol>
<p>Here is an example:</p>
<pre class="brush: shell">=&gt; setenv tftpserverip 192.168.1.60
=&gt; setenv nfsroot /srv/nfs/debian-arm64
=&gt; run netboot
</pre>[[Category:Imx8]]
[[Category:Nitrogen8M]]
[[Category:U-Boot]]