{"id":458,"date":"2026-09-23T23:23:06","date_gmt":"2026-09-23T23:23:06","guid":{"rendered":"https:\/\/kevinblog.sytes.net\/?p=458"},"modified":"2026-09-23T23:23:06","modified_gmt":"2026-09-23T23:23:06","slug":"adding-usb-gadget-support-to-jibos-kernel-while-in-host-mode","status":"publish","type":"post","link":"https:\/\/kevinblog.sytes.net\/?p=458","title":{"rendered":"Adding USB Gadget Support to Jibo’s Kernel while in host mode"},"content":{"rendered":"\n

So , up until now jibo isnt able to use the usb port to for example act as a usb device. This is mainly because of two reasons . we will talk about the second one as we go along but for starters jibo is a Tegra computer. it runs linux and it is build to utilize its usb port as a host. So if you were to plug in a keyboard . you can use it to type for example ,or plug in a thumb drive.

Now an arising question might be<\/p>\n\n\n\n

\n

Why do we wanna use jibo as a USB device;<\/mark><\/p>\n<\/blockquote>\n\n\n\n

Well there are some reasons , but two of the most important ones are <\/p>\n\n\n\n

    \n
  1. Be able to interface without a network<\/li>\n\n\n\n
  2. faster transfer speeds<\/li>\n<\/ol>\n\n\n\n

    While faster transfer speeds are nice, being able to interface with the shell without internet is actually really convenient & it will probably rescue softlocked robots stuck on oobe or with a broken touch screen or camera or , ofcourse a broken antenna.<\/p>\n\n\n\n

    So – The thing is running Uboot buildroot 2019ish. just mount the ci_hdrc<\/code> USB driver and we are done right;<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    Well turns out Jibo doesnt have this stuff out of the box (im guessing in an effort to save space since it only has like 16Gb of storage. <\/p>\n\n\n\n

    Well what do we have access to; , surprisingly… nothing USB related<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    To my insane luck , we can see that this kernel 3.10.104<\/code> has no USB gadget drivers. Without these its impossible to use the port as a gadget. So we are left with two options, Rebuild the kernel or… rebuild just the driver<\/p>\n\n\n\n

    Here is the thing i dont wanna rebuild the kernel, why; Well mainly because i dont have the device tree plus idk if there is anything special baked in that , plus honestly i dont have the will power to scout rn. So were gonna shoehorn a donor driver.

    To do that we will clone the same kernel (its important that its or else it wont accept it) and configure it for the TK1 chip<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    Now we will enable the USB drivers (you can do it through the TUI but i dont have ncurses)
    <\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    PS: CONFIG_USB_CHIPIDEA<\/code> should be y<\/code> not m<\/code>but it still doesnt build<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    That is because in older C versions -fno-common<\/code> became a default flag, causing multiple definitions of global variables like yylloc<\/code> in legacy lexer\/parser code to fail at link time instead of being merged. SO we will mark yylloc as extern and remove builtish binaries<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    And IT BUILDS!, but we arent done yet nonono. Now we have to build the actual standalone driver lets do that using:<\/p>\n\n\n\n

    make M=drivers\/usb\/chipidea modules\nmake M=drivers\/usb\/gadget modules<\/code><\/pre>\n\n\n\n
    AND WE HAVE THE DRIVERS!<\/p>\n\n\n\n
    \"\"<\/figure>\n\n\n\n
    we will try copying them over to the robot under like a test directory ~\/usb_driver_test\/<\/code> , and i have to officially present to you our creation!<\/p>\n\n\n\n
    \"\"<\/figure>\n\n\n\n
    The digital equivalent of making a hole on the water…. 

    Yeah apparently someone decided to stick the word -dirty<\/code> on the version… AAAAAAAAAAAAAAAAAAAAAAAAAAA

    So what… is it over…are you gonna recompile again

    Fuck no; Since we are on linux we can just tell it it can load it anyways and its gonna believe us, and low and behold <\/p>\n\n\n\n
    \"\"<\/figure>\n\n\n\n
    SO it loaded!!!!!… Or did it; <Insert Vsause song><\/p>\n\n\n\n
    Well you see im stupid and i never realized g_ether<\/code> and tegra-udc<\/code> was already running… so i did a small test and infact it crashed the usb controller … anyway ima leave it here and continue writing if something interesting happens EOF—<\/p>\n\n\n\n
    BGN—<\/p>\n\n\n\n
    So .. we blacked out .. but SOMETHING INTERESTING HAPPENED!<\/p>\n\n\n\n
    i was still trying so hard i ended up just writing values to random places and at some point…. i saw the magic words!
    <\/p>\n\n\n\n
    \"\"<\/figure>\n\n\n\n
    IT CAN CONNECT!!!!!!!!!!!!!!!!!!!!!!!!!!!! , ofc we can also set an ip and everything. Ping is virtually Zero and this also will allow for live debugging and more… anyways that enough for today – Tomorrow Troposphere<\/a> is getting a huge upgrade after months and better documentation on this
    <\/p>\n\n\n\n
    \n
    Im still remaking the GITea and i also moved Troposphere here… Everything including the site is under works so pleas bare with the setup \ud83d\ude42<\/mark><\/p>\n<\/blockquote>\n\n\n\n

    For now … Cya and good night!<\/p>\n\n\n\n
    <\/p>\n","protected":false},"excerpt":{"rendered":"
    So , up until now jibo isnt able to use the usb port to for example act as a usb device. This is mainly because of two reasons . we will talk about the second one as we go along but for starters jibo is a Tegra computer. it runs linux and it is build […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-458","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"featured_image_src":null,"author_info":{"display_name":"kevin","author_link":"https:\/\/kevinblog.sytes.net\/?author=1"},"_links":{"self":[{"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=\/wp\/v2\/posts\/458","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=458"}],"version-history":[{"count":1,"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=\/wp\/v2\/posts\/458\/revisions"}],"predecessor-version":[{"id":470,"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=\/wp\/v2\/posts\/458\/revisions\/470"}],"wp:attachment":[{"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=458"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=458"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kevinblog.sytes.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}