building for Nexus 7 deb

  • Hi! I understand that the Nexus 7 isn't supported by ubports at the moment. However with all the new energy around here I thought I give it a shot (again I think it shouldn't be too hard to build it, seeing that this device has been supported by UT at some point. Maybe someone around here can help me along.

    I am stuck at the lunch command - it doesn't include any option to build for deb.

    What I did so far, following the steps here

    mkdir phablet
    cd phablet
    repo init -u -b ubp-5.1
    mkdir .repo/local_manifests

    create .repo/local_manifests/asus_deb.xml :

    <?xml version="1.0" encoding="UTF-8"?>
    <remote name="cm"
    revision="refs/heads/cm-12.1" />

    remote="cm" revision="cm-12.1" />

    remote="cm" revision="cm-12.1" />

    remote="cm" revision="cm-12.1" />

    repo sync -c

    download Nexus7 (Mobile) binaries for Android 5.1.0 (LMY47O) from
    extract them

    source build/

    You're building on Linux

    Lunch menu... pick a combo:

    1. aosp_arm64-eng 2. aosp_arm-eng 3. aosp_mips64-eng 4. aosp_mips-eng 5. aosp_x86_64-eng 6. aosp_x86-eng

    So, lunch is not offering anything with "deb". Looking at this I would expect that there should be an option "aosp_deb-userdebug"

    Can someone help me here?

  • Ok, so reading through

    less build/

    especially the functions lunch and breakfast, I come to believe that the file vendor/cm/ is involved in this, which in turn seems to point to

    which is basically empty. That rings a bell for me about CyanogenMod being dead and having been reborn as LineageOS. Checking the corresponding

    I see it referring to

    The good news is that this one is not empty. The bad news is that this file is being grepped for 12.1 which again produces no hits.

    Either way, it looks like all the script does is call

    add_lunch_combo deb userdebug

    However when I execute this line directly and afterwards lunch, I see the following error.

    add_lunch_combo deb-userdebug
    lunch deb-userdebug

    build/core/ *** Can not locate config makefile for product "deb". Stop.
    Device deb not found. Attempting to retrieve device repository from CyanogenMod Github (
    Found repository: android_device_asus_deb
    Traceback (most recent call last):
    File "build/tools/", line 251, in <module>
    default_revision = get_default_revision()
    File "build/tools/", line 115, in get_default_revision
    return r.replace('refs/heads/', '').replace('refs/tags/', '')
    AttributeError: 'NoneType' object has no attribute 'replace'
    build/core/ *** Can not locate config makefile for product "deb". Stop.

    ** Don't have a product spec for: 'deb'
    ** Do you have the right repo manifest?

    So, that doesn't solve it either.

  • Ah, no, I guess it should be

    add_lunch_combo cm_deb-userdebug
    lunch cm_deb-userdebug

    that is progressing now, let's see where it goes.

  • ok that ran through until

    #### make completed successfully (01:04:37 (hh🇲🇲ss)) ####

    and I see

    cd out/target/product/deb/
    ls *.img
    boot.img cache.img ramdisk-android.img ramdisk-recovery.img ramdisk-ubuntu.img recovery.img system.img userdata.img

    however when I put my device into bootloader mode and then try

    fastboot boot recovery.img

    it boots and reboots and ends up in the TWRP recovery which is what is installed currently

    fastboot boot boot.img

    simply keeps on rebooting forever and ever. same happens when I do either of

    fastboot flash boot boot.img
    fastboot flash recovery recovery.img

    and then reboot into either system or recovery.

    so, what now?

  • @doniks Maybe you need to unlock smth? some devices protect everything from being overwritten? NOt sure about that

  • Mhm, no I don't think that's it. I did that oem unlock thingy a long time ago and had since had multiple android versions, multiple different recoveries, also UT for a lengthy period. So I don't think a lock is keeping me.

  • @doniks There is no logical reason why fastboot flash recovery recovery.img should not work, sorry then...

  • I tried the following:

    fastboot flash recovery twrp.img
    fastboot boot recovery.img

    observe that it boots the ubuntu recovery and then reboots into twrp recovery

    adb shell cat /proc/last_kmsg > last_kmsg

    When reading that logfile I spot the following towards the end:

    SELinux: Could not open sepolicy: No such file or directory
    init: SELinux: Failed to load policy; rebooting into recovery mode

    Sounds like I have a problem with SELinux!? But what to do?

  • @doniks SELinux is a kernel extension for security and policies. can you check the output of the kernel settings script for Ubuntu: => it will tell you what needs to be changed in the kernel config file, and it can also apply those changes. Then a rebuild of the kernel should get you going.


  • Ah thanks! I'll check that.

    But it makes me wonder ... I have a recovery that has trouble booting. But, stupid question: Is it a "cyanogenmod recovery" or is it an "ubports recovery"? I guess, I'm somewhere in between, right? The "repo init" brought the ubports side and the "local_manifest" brought in the cm side. If it were straight "cm only", then the resulting recovery would probably just boot. But then, I don't want cm, so, I'm venturing into ubp territory and those config options you linked are probably the next step deeper into ubp land.

    I'm rambling ... I'm just trying to understand what I'm actually doing, while copy pasting instructions.

    I see in the script there is a CONFIGS_OFF : CONFIG_DEFAULT_SECURITY_SELINUX

    that does indeed sound like it might resolve the problem. Let's see.

  • Alrighty! Welcome to the Ubports Recovery 🙂

    I applied most of what sounded like "turn off SELinux". I didn't apply all the check-config changes yet, because I was concerned about changing too many things at once and breaking more than fixing. (diff below)

    Recovery seems to be working fine now: Shows menu, I can navigate it with volup/voldown/power and with touch gestures, all actions I tried seemed to work. On to image building 🙂

    git diff

    arrrghhh .... forum software! why can I copy/paste a diff as plain text, which of course screws up the layouting of the post because it's misinterpreted as markdown, but I am NOT allowed to copy/paste into a

    code block

    because "Error

    Post content was flagged as spam by"

    Whatever, I adjusted the following:

  • @doniks You can safely apply all changes of this script - in fact they are all necessary, so dont bother with trying one by one 😉

  • @Flohack said in building for Nexus 7 deb:

    @doniks You can safely apply all changes of this script - in fact they are all necessary, so dont bother with trying one by one 😉

    Ok, let me try. I saw some apparmor stuff and thought .... uh, probably I need to hunt for kernel patches to make this work, let me postpone THAT headache ....

  • @doniks said in building for Nexus 7 deb:

    @Flohack said in building for Nexus 7 deb:

    @doniks You can safely apply all changes of this script - in fact they are all necessary, so dont bother with trying one by one 😉

    Ok, let me try.

    Yup, that was easy enough. Applied all changes. Rebuilt. Flashed recovery. Rebooted. Works just as well until here!

  • @doniks In general if you got a working CM kernel no real kernel patches are needed except apparmor3 => But you can try stealing that as a whole subdir from a kernel that has these patches applied. Should be more like copy/paste.


  • one step further. next road block. I've cloned the rootstock-ng thingy, downloaded the vivid....tar.gz, ran the rootstock thingy. It did it's thing, the tablet rebooted but is stuck at the Google logo screen. adb is not working. nothing seems to be happening. Not sure how to proceed, don't have any ideas 😞

  • I realize that there is a deb image in the rc channel

    ubuntu-device-flash --verbose --server= touch --device=deb --channel=ubuntu-touch/rc-proposed

    that installs and starts just fine. Poking around in that image, it seems to me as if the initrd is basically the same as my self built one, but the kernel config and the android system.img look quite different. Though, I still don't know what exactly to do ...

  • @doniks You might want to try the google_msm kernel in ubports. It already contains the apparmor and other backports:

    but it does not contain a reasonable kernel config for flo.

    You could also verify that the user space binaries and firmware files are being picked up get copied into the out/target/product/...../system directory.

    If none of that gets you any further - use adb while in recovery and go to /data/system-data and examine the var/log files for clues..

  • I meant deb .. not flo

  • @Andreas-Pokorny You can edit posts here xD

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