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| author | Leah Rowe <info@minifree.org> | 2016-09-03 18:06:48 +0100 |
|---|---|---|
| committer | Leah Rowe <info@minifree.org> | 2016-09-03 18:06:48 +0100 |
| commit | b9e8c1020a47a183fd9a533f7230197fbb86f472 (patch) | |
| tree | 29353762c49c0b72b7714eff692af4906a6b80b3 /docs/misc | |
| parent | 6a7d71cd4ce6abaa99ff26a1b0f38eecd8f07c83 (diff) | |
| download | librebootfr-b9e8c1020a47a183fd9a533f7230197fbb86f472.tar.gz librebootfr-b9e8c1020a47a183fd9a533f7230197fbb86f472.zip | |
docs/install/bbb_ehci.html moved to docs/misc/
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| -rw-r--r-- | docs/misc/bbb_ehci.html | 514 | ||||
| -rw-r--r-- | docs/misc/index.html | 1 |
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diff --git a/docs/misc/bbb_ehci.html b/docs/misc/bbb_ehci.html new file mode 100644 index 00000000..3cdda48a --- /dev/null +++ b/docs/misc/bbb_ehci.html @@ -0,0 +1,514 @@ +<!DOCTYPE html> +<html> +<head> + <meta charset="utf-8"> + <meta name="viewport" content="width=device-width, initial-scale=1"> + + <style type="text/css"> + @import url('../css/main.css'); + </style> + + <title>EHCI debugging on the BeagleBone Black</title> +</head> + +<body> + + <div class="section"> + <h1 id="pagetop">EHCI debugging on the BeagleBone Black</h1> + + <p><a href="index.html">Back to previous index</a></p> + </div> + + <div class="section"> + <h1>EHCI debugging</h1> + <ol class="toc"> + <li><a href="#FindUSBportonthetargetthatsupportsEHCIdebug">Find + USB port on the target that supports EHCI debug</a></li> + <li><a href="#InitialsetupofBBBtoactasEHCIdebugdongle">Initial + setup of BBB to act as EHCI debug dongle</a></li> + <li><a href="#PatchBBBsgdbgpmoduleoptionalbuthighlyrecommended">Patch + BBB's <tt>g_dbgp</tt> module (optional, but highly recommended)</a></li> + <li><a href="#ConfigurelibrebootwithEHCIdebug">Configure + libreboot with EHCI debug</a> + <ol> + <li><a href="#SelectingHCDIndexandUSBDebugport">Selecting + <tt>HCD Index</tt> and <tt>USB Debug port</tt></a></li> + </ol></li> + <li><a href="#Howtogetthedebuglogs">How to get the debug + logs</a></li> + <li><a + href="#EnebleEHCIDebugonthetargetskerneloptionalrecommended">Eneble + EHCI Debug on the target's kernel (optional, recommended)</a></li> + <li><a href="#References">References</a></li> + </ol> + <p>If your computer does not boot after installing libreboot, it is + very useful to get debug logs from it, from the payload (grub) and/or + the kernel (if gets to there). All of them stream debug logs on the + available serial (RS-232) by default. However, most of todays laptops + lack RS-232 port. The other option is to stream the logs to USB EHCI + debug port.</p> + <p>This section explains step-by-step how to setup BBB as a + “USB EHCI debug dongle” and configure libreboot and the + linux kernel to stream logs to it (TODO: grub).</p> + <p>I will refer to three computers:</p> + <ul> + <li><b>host</b> - this is the computer you use, have + tools, compiler, Internet, etc</li> + <li><b>BBB</b> - Beaglebone Black (rev. B or higher, i + use rev. C)</li> + <li><b>target</b> - the computer you are trying to + install liberboot</li> + </ul> + <h3 id="FindUSBportonthetargetthatsupportsEHCIdebug">Find USB port + on the target that supports EHCI debug</h3> + <p> + Not all USB controllers support EHCI debug (see: <a + href="http://www.coreboot.org/EHCI_Debug_Port#Hardware_capability">EHCI + Debug Port</a> ). Even more, if a USB controller supports EHCI debug, it + is available only <b>on a single port</b> that might or might + not be exposed externally. + </p> + <ul> + <li>You need running OS (GNU/Linux) on your target for this step + (If you’ve flashed libreboot and it does not boot, you have to + flush back the stock bios)</li> + <li>You need USB memory stick (the data on it will not be + touched).</li> + <li>The EHCI debugging can not be done through external hub, BBB + must be connected directly to the debug port of the controller (so, no + hubs)</li> + </ul> + <ul> + <li>Download<sup class="footnote"><a href="#___fn1">1</a></sup> <a + href="http://www.coreboot.org/pipermail/coreboot/attachments/20080909/ae11c291/attachment.sh">this</a> + shell script. + </li> + </ul> + <ol> + <li>Plug the usb stick in the first available usb port</li> + <li>Run the script, you will get output similar to following:</li> +<pre>The following PCI devices support a USB debug port (says lspci): 0000:00:1a.0 0000:00:1d.0 +The following PCI devices support a USB debug port (says the kernel): 0000:00:1a.0 0000:00:1d.0 +*PCI device 0000:00:1a.0, USB bus 3, USB physical port 1* +*PCI device 0000:00:1d.0, USB bus 4, USB physical port 2* +Currently connected high-speed devices: +/: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M + |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M + |__ Port 7: Dev 14, If 0, Class=Hub, Driver=hub/4p, 480M + |__ Port 1: Dev 15, If 0, Class=Hub, Driver=hub/4p, 480M + |__ Port 3: Dev 17, If 0, Class=Hub, Driver=hub/2p, 480M + |__ Port 4: Dev 18, If 0, Class=Hub, Driver=hub/4p, 480M +/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M + |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M +/: *Bus 01*.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M + |__ *Port 3: Dev 31, If 0, Class=Mass Storage, Driver=usb-storage, 480M* +</pre> + <li>The buses the support debug are Bus 3 (0000:00:1a.0) on Port 1 + and Bus 4 (0000:00:1d.0) on port 2. Your usb stick is plugged on Bus + 1, Port 3</li> + <li>Repeat the steps, plugging the USB stick in the next available + port</li> + <li>Go through all available ports and remember(write down) those + for which bus/port of the usb stick matches one of the bus/port that + support debug (bold).</li> + </ol> + <p>Remember (write down) for each port (external plug) you found + that supports debug: <b>PCI device id, the bus id, the port number, and + the physical location of the usb plug.</b></p> + <p>If you do not find a match, you can not get debug over EHCI. + Sorry.</p> + <p id="___fn1" class="footnote"> + <sup>1</sup> The guys from coreboot were talking about including the + script in coreboot distribution (check the status). + </p> + <h3 id="InitialsetupofBBBtoactasEHCIdebugdongle">Initial setup of + BBB to act as EHCI debug dongle</h3> + <p>BBB must be powered with a barrel power connector since the + mini-B USB plug will be used for the EHCI debug stream. So you will + need:</p> + <ul> + <li>power supply (5V, 2A(10W) is sufficient).</li> + <li>an extra usb cable: A to mini-B</li> + </ul> + <p> + (On BBB) The linux kernel includes module (g_dbgp that enables one of the usb ports on a computer to behave as EHCI + debug dongle. Make sure you have this module available on your BBB + (Debian 7.8 that comes with BBB should have it), if not, you should + compile it yourself (see next section): + </p> +<pre>ls /lib/modules/3.8.13-bone70/kernel/drivers/usb/gadget/g_dbgp.ko</pre> + <p> + Unload all other + g_* + modules: + </p> +<pre># lsmod +# rmmod g_multi +... +</pre> + <p> + Then load + g_dbgp + : + </p> +<pre># modprobe g_dbgp +# lsmod # should show that g_dbgp is loaded, and no other g_* +</pre> + <p> + Plug the mini-B side of the USB cable in your BBB and the A side in + your target. Then one of the usb devices on your target (with + lsusb + ) should be: + </p> +<pre>Bus 001 Device 024: ID 0525:c0de Netchip Technology, Inc.</pre> + <p>If you see the device on the target, you are good to continue to + the next step.</p> + <h3 id="PatchBBBsgdbgpmoduleoptionalbuthighlyrecommended"> + Patch BBB’s + g_dbgp + module (optional, but highly recommended) + </h3> + <p> + For the reasons why you need this, see: <a + href="http://www.coreboot.org/EHCI_Gadget_Debug">EHCI Gadget Debug</a>.<br />Make + sure that you have cross compiling environment for + arm-linux-gnueabihf + setup on your <em>host</em>. + </p> + <ul> + <li>On BBB: uname -r - this will give you version + number like 3.8.13-bone70 (I will refer to this as: $mav.$miv-$lv: + where mav=3.8, miv=13, lv=bone70 + </li> + <li>Get the BBB kernel ready on your host for cross-compiling:</li> + </ul> +<pre>$ cd $work_dir +$ git clone https://github.com/beagleboard/kernel.git +$ cd kernel +$ git checkout $mav (see above) +$ ./patch.sh +$ wget http://arago-project.org/git/projects/?p=am33x-cm3.git\;a=blob_plain\;f=bin/am335x-pm-firmware.bin\;hb=HEAD -O kernel/firmware/am335x-pm-firmware.bin +$ cp configs/beaglebone kernel/arch/arm/configs/beaglebone_defconfig +</pre> + <ul> + <li>Download the patch from <a + href="http://www.coreboot.org/images/8/88/Ehci-debug-gadget-patches.tar.gz">here</a></li> + <li>tar -xf Ehci-debug-gadget-patches.tar.gz (will + create dir: usbdebug-gadget)</li> + <li>Note that there are two patches (patch_1 and patch_2) for each + of the two different version of the kernel (3.8 and 3.10). I will use + 3.8. (If using kernel 3.12 patch_1 is not needed)</li> + <li>cd kernel (note that this is one more level: you + should be in $work_dir/kernel/kernel)</li> + <li>Apply the patches:</li> + </ul> +<pre> +git apply ../usbdebug-gadget/v3.8-debug-gadget/0001-usb-dbgp-gadget-Fix-re-connecting-after-USB-disconne.patch +git apply ../usbdebug-gadget/v3.8-debug-gadget/0002-usb-serial-gadget-no-TTY-hangup-on-USB-disconnect-WI.patch +; +make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- beaglebone_defconfig -j4@ +</pre> + <ul> + <li> + You should also apply the linux-libre <i>deblob</i> script to turn it into linux-libre + (deletes all the blobs from the linux kernel). + <a href="http://www.fsfla.org/ikiwiki/selibre/linux-libre/">fsfla website</a> + - see <a href="http://www.fsfla.org/svn/fsfla/software/linux-libre/scripts/">scripts</a>. + </li> + <li>Get your current BBB kernel config (from: /boot/config-<ver>) + and copy it to your host as $work_dir/kernel/kernel/.config</li> +<pre> +make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- oldconfig - all default answers</pre> + <li>Set proper version number: + <ul> + <li>On your host, edit $work_dir/kernel/kernel/.config + (the one you’ve just copied from BBB), find the line CONFIG_LOCALVERSION="<something + or empty>" and change it to CONFIG_LOCALVERSION="-$lv", + so it will look something like: CONFIG_LOCALVERSION="-bone70"</li> + </ul> + </li> + <li>Also, make sure that: CONFIG_USB_G_DBGP=m (If + not, make menuconfig, and set @Device Drivers-> USB + Support -> USB Gadget Support -> EHCI Debug Device Gadget=m</li> + <li>Build the module:</li> + </ul> +<pre> +$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j4 (is it possoble to build only the gadget modules) +$ mkdir ../tmp && make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_MOD_PATH=../tmp modules_install +</pre> + <ul> + <li>on BBB, backup /lib/modules/3.8.13-bone70/kernel/drivers/usb/gadget + (i.e. mv + /lib/modules/3.8.13-bone70/kernel/drivers/usb/gadget $HOME) + </li> + <li>copy the freshly compiled usb/gadget dir to /lib/modules/3.8.13-bone70/kernel/drivers/usb</li> + <li>restart BBB</li> + <li>Remove all g_* modules (rmmod + g_<>) + </li> + <li>modprobpe g_dbgp</li> + </ul> + <h3 id="ConfigurelibrebootwithEHCIdebug">Configure libreboot with + EHCI debug</h3> + <p> + Libreboot(coreboot) should be configured with debug turned on and to + push debug messages to the EHCI debug port.<br />If you’ve + downloaded the binary distribution, you can check if it is properly + configured in the following way: + </p> + <ul> + <li>Go to the libreboot dist root directory cd + $libreboot_bin</li> + <li>Locate the rom image for your target (I will call it: $img_path) + </li> + <li>Running the following command will extract the config in a + file ./my_config: + </li> + </ul> +<pre> +./cbfstool/i686/cbfstool $img_path extract -n config -f ./my_config +</pre> + <ul> + <li>Make sure that the following params in the config are set as + following:</li> + </ul> +<pre> +CONFIG_USBDEBUG=y (Generic Drivers -> USB 2.0 EHCI debug dongle support) +CONFIG_USBDEBUG_IN_ROMSTAGE=y (Generic Drivers -> Enable early (pre-RAM) usbdebug) +CONFIG_USBDEBUG_HCD_INDEX=<HCD Index of usb controller - see below> (Generic Drivers -> Index for EHCI controller to use with usbdebug) +CONFIG_USBDEBUG_DEFAULT_PORT=<USB Debug port - see below> (Generic Drivers -> Default USB port to use as Debug Port) +</pre> + <p> + The following three are behind radio button in the menu. Only the first + one<sup class="footnote"><a href="#___fn2">2</a></sup> should be = y + </p> +<pre> +USBDEBUG_DONGLE_STD=y (Generic Drivers -> Type of dongle (Net20DC or compatible) -> Net20DC or compatible) +CONFIG_USBDEBUG_DONGLE_BEAGLEBONE=n (Generic Drivers -> Type of dongle (Net20DC or compatible) -> BeagleBone) +CONFIG_USBDEBUG_DONGLE_BEAGLEBONE_BLACK=n (Generic Drivers -> Type of dongle (Net20DC or compatible) -> BeagleBone Black) +</pre> + <p id="___fn2" class="footnote"> + <sup>2</sup> The g_dbgp module on BeagleBone Black (Rev. C) reports it self as Net20DC, the + other options are for older BB(B) - ver1. This is documented <a + href="https://johnlewis.ie/coreboot-ehci-debug-gadget-demonstration/">here</a> + (also tested/verified). + </p> + <p> + Then:<br /> +<pre> +CONFIG_CONSOLE_USB=y (Console -> USB dongle console output) +</pre> + </p> + <p> + Also + Debugging ---> Output verbose XYZ + ) (<b>FIXME</b> somebody verify these): + </p> +<pre> +CONFIG_DEBUG_CBFS=y (Output verbose CBFS debug messages ) +CONFIG_HAVE_DEBUG_RAM_SETUP=y (??? What/where is this) +CONFIG_DEBUG_RAM_SETUP=y (Output verbose RAM init debug messages) +CONFIG_DEBUG_SMI=y (Output verbose SMI debug messages) +CONFIG_DEBUG_ACPI=y (Output verbose ACPI debug messages ) +CONFIG_DEBUG_USBDEBUG=y (Output verbose USB 2.0 EHCI debug dongle messages) +</pre> + <p>If some of the above mentioned configuration options are not as + specified, you have to configure and compile libreboot yourself. Please + refer to the doc(<b>FIXME: link</b> about compiling libreboot.</p> + <h4 id="SelectingHCDIndexandUSBDebugport"> + Selecting + HCD Index + and + USB Debug port + </h4> + <p> + This applies (and works) only if the USB controller that supports debug + (found in the first section) is from Intel.<br />If the PCI ID of the + port you found in the first section is + 0000:00:1a.0 + or + 0000:00:1d.0 + , you are ok. Otherwise you have to try without guarantee that will + work. + </p> + <p> + If the externally exposed port is on a bus with + PCI ID == 0000:00:1a.0 + then for + CONFIG_USBDEBUG_HCD_INDEX + choose 2, otherwise choose 0 + . + </p> + <p> + For + CONFIG_USBDEBUG_DEFAULT_PORT + choose the port from the first section that correspond to the + PCI ID + </p> + <p> + Notes:<br />The above is based on the implementation of + coreboot/src/southbridge/intel/common/usb_debug.c : pci_ehci_dbg_dev() + .<br />This is enough as it applies for the supported GM45/G45 + Thinkpads. coreboot support some other contollers too, but they are + irellevent for libreboot (for now). + </p> + <ul> + <li>On T500 (with switchable GPU) the debug ports for both intel + controllers is exposed.</li> + <li>On x200t the debug ports for both intel controllers is + exposed.</li> + </ul> + <h3 id="Howtogetthedebuglogs">How to get the debug logs</h3> + <ul> + <li>Plug the USB cable in the target’s debug port (the one + you found in step 1) and BBB’s mini-B USB</li> + <li>Make sure no other then g_dbgp of the g_* + modules is loaded on your BBB + </li> + <li>On the BBB:</li> + </ul> +<pre> +stty -icrnl -inlcr -F /dev/ttyGS0 +cat /dev/ttyGS0 +</pre> + <ul> + <li>Power on the target with libreboot</li> + <li>You should see debug logs comming on your BBB console</li> + </ul> + <p> + Note that this is not permanent on BBB, if you reboot it, you have to + rmmod g_* + and + modprobe g_dbgp + </p> + <h3 id="EnebleEHCIDebugonthetargetskerneloptionalrecommended">Eneble + EHCI Debug on the target’s kernel (optional, recommended)</h3> + <p>You have to know how to compile kernel for your target.</p> + <ol> + <li>Check if early debugging is already enabled: grep + CONFIG_EARLY_PRINTK_DBGP /boot/config-<ver></li> + <li>If enabled, you do not have to compile the kernel (skip this + step). Otherwise, prepare kernel source for your distribution and + select (Kernel hacking -> Early printk via EHCI debug + port). Compile and install the new kernel. + </li> + <li>Edit your grub configuration and add following to the kenel + parameters<sup class="footnote"><a href="#___fn20">20</a></sup><sup + class="footnote"><a href="#___fn21">21</a></sup>: earlyprintk=dbgp,keep. + Also, try: earlyprintk=dbgp<N>,keep where N + is the debug port id if the first does not work. + </li> + </ol> + <h3 id="References">References</h3> + <p id="___fn10" class="footnote"> + <sup>10</sup> <a href="http://www.coreboot.org/EHCI_Debug_Port">EHCI + Debug Port</a> + </p> + <p id="___fn11" class="footnote"> + <sup>11</sup> <a + href="https://johnlewis.ie/coreboot-ehci-debug-gadget-demonstration/">coreboot + EHCI debug gadget demonstration</a> + </p> + <p id="___fn12" class="footnote"> + <sup>12</sup> <a href="http://www.coreboot.org/EHCI_Gadget_Debug">EHCI + Gadget Debug</a> + </p> + <p id="___fn13" class="footnote"> + <sup>13</sup> <a + href="http://www.coreboot.org/images/8/88/Ehci-debug-gadget-patches.tar.gz">Ehci-debug-gadget-patches.tar.gz</a> + </p> + <p id="___fn14" class="footnote"> + <sup>14</sup> <a + href="http://wiki.beyondlogic.org/index.php/BeagleBoneBlack_Building_Kernel">Compiling + the BeagleBone Black Kernel</a> + </p> + <p id="___fn15" class="footnote"> + <sup>15</sup> + http://dumb-looks-free.blogspot.ca/2014/06/beaglebone-black-bbb-compile-kernel.html + </p> + <p id="___fn16" class="footnote"> + <sup>16</sup> + http://dumb-looks-free.blogspot.fr/2014/06/beaglebone-black-bbb-kernal-headers.html + </p> + <p id="___fn17" class="footnote"> + <sup>17</sup> <a href="http://elinux.org/Building_BBB_Kernel">Building + BBB Kernel</a> + </p> + <p id="___fn18" class="footnote"> + <sup>18</sup> + http://komposter.com.ua/documents/USB-2.0-Debug-Port%28John-Keys%29.pdf + </p> + <p id="___fn19" class="footnote"> + <sup>19</sup> <a href="http://cs.usfca.edu/~cruse/cs698s10/">Exploring + USB at the Hardware/Software Interface</a> + </p> + <p id="___fn20" class="footnote"> + <sup>20</sup> + https://www.kernel.org/doc/Documentation/x86/earlyprintk.txt + </p> + <p id="___fn21" class="footnote"> + <sup>21</sup> https://wiki.ubuntu.com/Kernel/Debugging/USBearlyprintk + </p> + <p> + <b>TODO</b>: + </p> + <ol> + <li>grub does not send messages to EHCI debug. Investigate.</li> + <li>The section “Configure libreboot with EHCI debug” + can be skipped/simplified if a common configuration works for all + relevant targets is selected as defualt</li> + <li>Patch and compule g_dbgp on BBB instead cross-compile</li> + <li>Find a simple way to send debug messages from targets userland</li> + </ol> + </div> + + <div class="section"> + + <p> + Copyright © 2015 Alex David <opdecirkel@gmail.com><br/> + Permission is granted to copy, distribute and/or modify this document + under the terms of the GNU Free Documentation License, Version 1.3 + or any later version published by the Free Software Foundation; + with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. + A copy of the license can be found at <a href="../gfdl-1.3.txt">../gfdl-1.3.txt</a> + </p> + + <p> + Updated versions of the license (when available) can be found at + <a href="https://www.gnu.org/licenses/licenses.html">https://www.gnu.org/licenses/licenses.html</a> + </p> + + <p> + UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE + EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS + AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF + ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, + IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, + WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR + PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, + ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT + KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT + ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU. + </p> + <p> + TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE + TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, + NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, + INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, + COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR + USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN + ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR + DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR + IN PART, THIS LIMITATION MAY NOT APPLY TO YOU. + </p> + <p> + The disclaimer of warranties and limitation of liability provided + above shall be interpreted in a manner that, to the extent + possible, most closely approximates an absolute disclaimer and + waiver of all liability. + </p> + + </div> + +</body> +</html> diff --git a/docs/misc/index.html b/docs/misc/index.html index 3efb4866..8b05f17d 100644 --- a/docs/misc/index.html +++ b/docs/misc/index.html @@ -26,6 +26,7 @@ <li><a href="patch.html">Using diff and patch</a></li> <li><a href="#backlight control">Finetune backlight control on intel gpu’s</a></li> <li><a href="#get_edid_panelname">Get EDID: Find out the name (model) of your LCD panel</a></li> + <li><a href="bbb_ehci.html">How to enable EHCI debugging on the BeagleBone Black</a></li> </ul> </div> |