<h2>I installed openFPGALoader but it says <cite>command not found</cite> when I try to launch it<aclass="headerlink"href="#i-installed-openfpgaloader-but-it-says-command-not-found-when-i-try-to-launch-it"title="Link to this heading">¶</a></h2>
<p>The correct spelling of the program is <em>openFPGALoader</em> with FPGA and the “L” of “Loader” in uppercase.
Ensure the spelling of the program is correct.</p>
<h2>Gowin device could not communicate since last bitstream flashed. (issue <aclass="reference external"href="https://github.com/trabucayre/openFPGALoader/issues/206">#206</a>)<aclass="headerlink"href="#gowin-device-could-not-communicate-since-last-bitstream-flashed-issue-206"title="Link to this heading">¶</a></h2>
<p>Gowin’s FPGA may fails to be detected if <strong>JTAGSEL_N</strong> (pin 08 for <em>GW1N-4K</em>) is used as a GPIO.
To recover you have to pull down this pin (before power up) to recover JTAG interface (<em>UG292 - JTAGSELL_N section</em>).</p>
</section>
<sectionid="jtag-init-failed">
<h2>JTAG init failed<aclass="headerlink"href="#jtag-init-failed"title="Link to this heading">¶</a></h2>
<p>Avoid using USB hubs and connect it directly to your PC USB port.</p>
<h2>Tang Primer 20k program slow and stucked (issue <aclass="reference external"href="https://github.com/trabucayre/openFPGALoader/issues/250">#250</a>)<aclass="headerlink"href="#tang-primer-20k-program-slow-and-stucked-issue-250"title="Link to this heading">¶</a></h2>
<p>If it is older than release then v0.9.0, install the most recent version (from commit <aclass="reference external"href="https://github.com/trabucayre/openFPGALoader/commit/fe259fb78d185b3113661d04cd7efa9ae0232425">f5b89bff68a5e2147404a895c075773884077438</a> or later).</p>
<h2>Cannot flash Tang Nano 20k (issue <aclass="reference external"href="https://github.com/trabucayre/openFPGALoader/issues/511">#251</a>)<aclass="headerlink"href="#cannot-flash-tang-nano-20k-issue-251"title="Link to this heading">¶</a></h2>
<p>Some firmware version cannot be flashed on Linux-based systems. Version 2024122312 is such an example. It seems this version was not published on the <aclass="reference external"href="https://api.dl.sipeed.com/TANG/Debugger/onboard/BL616/">SiPeed website</a>, however some boards sold have this firmware.</p>
<p>The cause of the problem is the debugger on the Tang Nano, specifically the firmware of this debugger. This firmware can be easily updated by following <aclass="reference external"href="https://wiki.sipeed.com/hardware/en/tang/common-doc/update_debugger.html">these</a> steps.</p>
</section>
<sectionid="cannot-flash-tang-nano-9k-issue-251">
<h2>Cannot flash Tang Nano 9k (issue <aclass="reference external"href="https://github.com/trabucayre/openFPGALoader/issues/251">#251</a>)<aclass="headerlink"href="#cannot-flash-tang-nano-9k-issue-251"title="Link to this heading">¶</a></h2>
<p>This is a device issue, erase its Embedded Flash using Official GoWin Programmer (preferentially in Windows) and SRAM too, then you can use openFPGALoader again.</p>
<h2>Unable to open FTDI device: -4 (usb_open() failed) (issue <aclass="reference external"href="https://github.com/trabucayre/openFPGALoader/issues/245">#245</a>)<aclass="headerlink"href="#unable-to-open-ftdi-device-4-usb-open-failed-issue-245"title="Link to this heading">¶</a></h2>
<p>Edit your <cite>/etc/udev/rules.d/99-ftdi.rules</cite> file exchanging your programming device permissions.</p>
<p>For more information, check the udev section from <aclass="reference external"href="install.rst">this guide</a></p>
<h2>Converter cannot be opened: <cite>fails to open device</cite> (issue <aclass="reference external"href="https://github.com/trabucayre/openFPGALoader/issues/626">#626</a>)<aclass="headerlink"href="#converter-cannot-be-opened-fails-to-open-device-issue-626"title="Link to this heading">¶</a></h2>
<p>This is usually a permissions issue on Linux.</p>
<h2>Unable to flash device on OpenBSD: <cite>JTAG init failed with: DirtyJtag: fails to open device</cite><aclass="headerlink"href="#unable-to-flash-device-on-openbsd-jtag-init-failed-with-dirtyjtag-fails-to-open-device"title="Link to this heading">¶</a></h2>
<p>Certain evaluation boards may show the following error message when running openFPGAloader on OpenBSD:</p>
<p>This issue is most likely caused by the uftdi(4) module, which has attached itself to the device, whereas openFPGALoader requires it to be accessible as a ugen(4) device.</p>
<p>Unfortunately, due to the security concept of OpenBSD, it is not possible to detach it without modifying the kernel and rebooting the system. However, there are two ways to resolve the issue: Either by patching and recompiling the kernel; or by deactivating the uftdi(4) module.</p>
<p>After COMMENTING OUT the problematic devices in <cite>/usr/src/sys/dev/usb/uftdi.c</cite>, the code would look like this:</p>
<p>With this manual patch applied, the steps in <cite>https://www.openbsd.org/faq/faq5.html <https://www.openbsd.org/faq/faq5.html#Custom></cite> can be used to recompile the kernel.</p>
<p>Without recompilation, DEACTIVATING uftdi(4) can be achieved using the following commands:</p>
<divclass="highlight-bash notranslate"><divclass="highlight"><pre><span></span><spanclass="c1"># doas config -e -f -o /bsd.nouftdi /bsd</span>
OpenBSD<spanclass="w"></span><spanclass="m">7</span>.8<spanclass="w"></span><spanclass="o">(</span>GENERIC<spanclass="o">)</span><spanclass="w"></span><spanclass="c1">#54: Sun Oct 12 12:45:58 MDT 2025</span>
<liclass="toctree-l2"><aclass="reference internal"href="#i-installed-openfpgaloader-but-it-says-command-not-found-when-i-try-to-launch-it">I installed openFPGALoader but it says <cite>command not found</cite> when I try to launch it</a></li>
<liclass="toctree-l2"><aclass="reference internal"href="#gowin-device-could-not-communicate-since-last-bitstream-flashed-issue-206">Gowin device could not communicate since last bitstream flashed. (issue #206)</a></li>
<liclass="toctree-l2"><aclass="reference internal"href="#tang-primer-20k-program-slow-and-stucked-issue-250">Tang Primer 20k program slow and stucked (issue #250)</a></li>
<liclass="toctree-l2"><aclass="reference internal"href="#converter-cannot-be-opened-fails-to-open-device-issue-626">Converter cannot be opened: <cite>fails to open device</cite> (issue #626)</a></li>
<liclass="toctree-l2"><aclass="reference internal"href="#unable-to-flash-device-on-openbsd-jtag-init-failed-with-dirtyjtag-fails-to-open-device">Unable to flash device on OpenBSD: <cite>JTAG init failed with: DirtyJtag: fails to open device</cite></a></li>
