Installing gentoo on nexus 7 WiFi 2012 [Work in progress ;]

[deadram]

By the by, I'm talking about a nexus 7 WiFi 2012, no GSM, running a Nvidia quad core, not Qualcom, or whatever the 2013 is.

Has anybody else tried this?

I've found the images to install ubuntu from this forum: http://forum.xda-developers.com/showthread.php?t=2011403

The 2 image files can be downloaded here: http://cdimage.ubuntu.com/releases/13.04/release/

Your looking for:
ubuntu-13.04-preinstalled-desktop-armhf+nexus7.bootimg
ubuntu-13.04-preinstalled-desktop-armhf+nexus7.img.gz

(I'll be keeping backup copies, if the ubuntu servers remove them. Anyone with a host at that time can tell me to edit this page with a kind donation of file space of coarse )

Once they are downloaded, go to fastboot mode on your nexus 7 (power off, then hold power and vol down), plug in usb, and from your computer (with adb installed, and should come with fastboot), issue these commands:

$ fastboot flash boot ubuntu-13.04-preinstalled-desktop-armhf+nexus7.bootimg
...
erasing boot #or too that effect
...
success #or too that effect - omitted from now on
...
$ gunziup ubuntu-13.04-preinstalled-desktop-armhf+nexus7.img.gz
...
$ fastboot flash userdata ubuntu-13.04-preinstalled-desktop-armhf+nexus7.img
...
$ fastboot reboot

Now you can unplug your nexus 7, and follow the boring ubuntu (the M$ of linux?) GUI prompts...

However there is the simg2img tool from google, and a make_ext4fs tool, but it's not a regular ext4, it's an android ext4 fs - that will be used by the fastboot command to flash the stupid almost proprietary image to the device. It'd like to drop in either a stage 3 tarball, or a live dvd image, instead of the ubuntu install.

Anyone ever go down this path before me? I've hacked out an esmtp patch that made it into esmtp, and eventually stable gentoo, and now I don't need my own overlay anymore. So I know C/CPP/Anything less complicated then ~some~ assembly. Any tips or ideas? From what I've seen of ubuntu, there is no working tty, and in that case, live minimals, and live CD won't work, need to get into X automagically, at least that's what the ubuntu people do. Anyone else interested in uninstalling android on the "official example of android devices" and getting a real OS on there?
_________________
echo deadram; fortune

[deadram]

A little update, I've managed to crash gentoo at /sbin/init... so basically yah XD lol... the very, very, very start of the computer, except BIOS and kernel. Have a feeling it's because of some missing files from my image due to low memory and other such funnyness when i was preparing the stage3 from unbuntu, on the nexus. good news though, you can prepare a armv7-hardfp stage3 gentoo chroot from ubuntu, get to the point it has wifi, and a few other things ready, and then ftp the tarball over to another computer, to be packed by make_ext4fs, and flashed by fastboot.

I'll be giving it a few more tries today, and if I can get something working, I'll bother to make a whole set of directions.

Ohh, and as an aside, it looks like getty type consoles will work. unbuntu is probably just having trouble managing x-windows, and framebuffer, and getty... or is that the nvidia driver team having trouble? XD Anyways, get ubuntu on your nexus 7, and get into fastboot, and do this: "fastboot erase system ; fastboot erase recovery ; fastboot reboot" You should now crash, gracefully, to a console with working usb keyboard (sorry, no onscreen kb).
_________________
echo deadram; fortune

[deadram]

Seems I've figured it out I've got a console at least

http://i.imgur.com/XjIDruA.jpg

What works
• Boot
• Init
• shutdown
• Most programs
• mmcblk access
• usb keyboard
• tegrafb - framebuffer

What probably works (untested, but they seem to load the drivers)
• sound
• wifi
• Touchscreen
• bluetooth
• power and volume buttons (after a little configuring)
• cpugov
• kernel updates (they are possible, but you'll have to figure out the mkbootimg from AOSP)

What probably doesn't work (These are just guesses, and with enough work, could be fixed)
• adb
• android! and android apps too!
• Screen orientation changes
• screen dimming

So the how-to...

• Download the ubuntu install for version 13.04 ubuntu-13.04-preinstalled-desktop-armhf+nexus7.bootimg, and ubuntu-13.04-preinstalled-desktop-armhf+nexus7.img.gz
  
• Install, following ubuntu directions
  
• Once ubuntu is up, and running, open a term
  
• type "sudo passwd" to set the root password
  
• "su"
  
• "mkdir gentoo ; cd gentoo ; tar xvhjf ../Downloads/<stage3>.tar.bz2 ; cd usr ; tar xvhjf ../../Downloads/<portage>.tar.bz2"
  
• "cd .."
  
• "mount --rbind /sys sys ; mount --rbind /dev dev ; mount -t proc proc proc"
  
• "cp /etc/resolv.conf ./etc"
  
• "chroot /home/<username>/gentoo /bin/bash"
  
• "env-update && source /etc/profile"
  
• Now follow the handbook directions until they ask you to reboot... But don't reboot
  
• "exit" your chroot
  
• "umount -l ./dev ; umount -l ./sys ; umount proc"
  
• "cd dev ; cat /proc/partitions" now do a mknod <major> <minor> <mmcblkXpY> for each entry in the partitions info (this is more for if something bad goes down, but you still make it to a limited shell
  
• "cd /home/<user>/gentoo ; tar cvzf ../rootfs.tar.gz ./"
  
• Upload the rootfs.tar.gz file to your computer, via ftp, scp, or whatever you like

=== Now on your computer (with your nexus 7 tablet in fastboot mode)

• $mkdir rootfs
  
• $cd rootfs
  
• $cp ~/pathtorootfsfile/rootfs.tar.gz ./
  
• $cd ..
  
• $make_ext4fs -s -l 6G -a data userdata.img ./rootfs
  
• $fastboot erase userdata
  
• $fastboot flash userdata userdata.img
  
• $fastboot reboot

Should get into the stage3 gentoo install you setup on ubuntu, just give it a few minutes. I've had trouble with make_ext4fs with -l higher then 6G, so I only get a 6G data partition (even on a 32G nexus device). Also keep in mind to compile make_ext4fs with the -DANDROID gcc option, or funny things seem to happen. make_ext4fs is part of the AOSP too.

I'm going to try to edit the bootimg, and see if I can plop the copy into 'recovery' with system as the rootfs as a basic backup boot... Anyways, this seems to be headed in the direction I wanted If anyone wants help setting up gentoo on a Nexus 7 WiFi 2012, just post in this thread I guess?

EDIT ---

Forgot to mention, when your making your stage3 from ubuntu, "cp -a /lib/mod* /home/<user>/gentoo/lib" for your modules.

Also, seems to have trouble with the 2nd bootup. I have a feeling there's some files that the ubuntu bootimg modifies to indicate "installed ubuntu", and if I can edit the initramfs of the bootimg, or make the correct directories for the bootimg to store the "installed" state, that will be fixed

EDIT2 ---

Also forgot to grab /lib/fireware from the ubuntu root, and put it into the rootfs.tar.gz on my device. I'm at work now, without computer, so that'll have to wait till later tonight, or tomorrow.

ubuntu comes with an arm abootimg binary, in the bin dir, I believe. You'll want that, and possibly the source, to compile on your computer as well. That can extract the kernel, initramfs, and boot config (basically the cmdline passed to the kernel), and recompress them, into a format fastboot will understand.

I'm starting to think hacking about the ubuntu initramfs isn't going to work, I may grab the AOSP kernel from git, and try to compile a kernel without an initramfs, and boot directly into mccblk0p9 (the userdata partition, at least on my device). I'll have to figure out if the nexus can boot without an initramfs though, since abootimg seems to really want one to drop into the boot record.

FYI, from my digging, it looks like mmcblk0p2 is the "default" boot record. I'm guessing mmcblk0p1 or p4 will be the recovery boot record. It also seems that you can flash a "default" boot.img into the recovery with "fastboot flash recovery boot.img" and boot it up by getting into the bootloader (hold vol down when powering up) and selecting recovery. Probably could also do stuff like "cat boot.img > /dev/mmcblk0p2" from the nexus. That gives us at least a primary boot, and a backup.

Anywho, I'll plug away at it tonight, and see if I can get something booted, and decent.
_________________
echo deadram; fortune

[reanimus]

Coincidentally, I just decided I want to do something similar. Do you need a USB-OTG cable?

[deadram]

@reanimus I use the regular USB to micro USB cable from my computer, to the nexus 7 for adb/fastboot. Once in gentoo (unless your in ubuntu with gentoo chroot) you will not have an onscreen keyboard. So a few options, either set-up wifi and sshd on the nexus, and ssh from your computer, or use a USB keyboard. I've got a micro-USB keyboard and carry case combo, but the USB-OTG cable would work too. (if your interested, here's the amazon link http://www.amazon.ca/Black-Leather-Interface-Keyboard-Tablet/dp/B008IBDQ04/ref=sr_1_1?s=electronics&ie=UTF8&qid=1408916670&sr=1-1&keywords=micro+usb+keyboard - works well, but most of the symbols are cluttered on the right side... don't know why these things can't come with a real full keyboard, just micro sized buttons XD)

There's also a dock port, on the opposite side of the power and volume buttons on the nexus 7. It's just 4 gold colored pins about 1cm apart, one side is +5V other is ground, middle are data I'm guessing. Seems to be just an extra usb port, with a proprietary form factor. I'll probably solder some wires to it later on, and see if I can get an extra usb port to use keyboard and charge at the same time.

I believe an unpowered usb hub wouldn't work well, but a powered usb hub, with the OTG cable is probably the best solution for getting say an external HD, keyboard and mouse connected - or anything else that connects by usb to a computer.

---

Also, I can confirm mmcblk0p1 is recovery, and mmcblk0p2 is boot. Both are roughly 10MB in size. mmcblk0p3 is system at a perfect 650MB, and cache is mmcblk0p4 with about 450MB... good enough for a /boot partition, plenty of space for backup kernel images. mmcblk0p9 is the userdata, but the other 4 I'm not too sure.

mmcblk0p7 seems to mount, at 5MB, but I haven't figured out what's in there yet. mmcblk0p5 and p8 are both all zeros, and only 512Kb. mmcblk0p6 seems to be all zeros as well, but 10MB. At least from ubuntu. Might be worth checking them out from rooted android to see if they show anything different.

boot1 and boot2 I'm not sure of either. "hexdump <name> | head" didn't find anything similar to the bootloader.img file from android. I don't want to play too much with it either, don't want to accidentally over-write the bootloader and hard-brick the nexus.

EDIT ---

Got a ubuntu 13.10 kernel to boot gentoo, directly without any initramfs. Seems to be rather unstable though, and it'll take me a while to grab a backup of my gentoo system and restore the old ubuntu install. I noticed once syslog-ng starts, there seems to be a kernel panic (or a lot of text hitting the screen before a reboot). didn't bother reading it, have a feeling ubuntu is using a modified AOSP kernel, and the AOSP kernel is so stupid, as to remove basic function from the real linux kernel.

Anywho, I'll try a gentoo kernel next, and try to see if the tegra chipset will even accept VGA drivers, and the likes, to get basic function from the device.

EDIT2 ---

Had trouble booting with a gentoo kernel. going to give it a few more tries later in the week. Seem to have found a stable kernel/initramfs though. The ubuntu bootimg, and userdata image are different once you install the ubuntu system. So to get a decent gentoo working, install ubuntu, reboot, copy the /dev/mmcblk0p2 partition, extract the kernel and initramfs and config (with abootimg on the ubuntu install), edit the config file to have the kernel boot args you want, and repack with abootimg. Next just install a stage3 on a directory like /home/user/gentoo. then use http://teamw.in/project/twrp2/103 and flash it to recovery... we only need this step to boot into twrp2 and then adb shell from a computer. move the root dir of mmcblk0p9 to a folder named ubuntu, and move the /ubuntu/home/user/gentoo directories to the root of mmcblk0p9. adb shell from twrp2 is root, and if you mount the /system partition you'll probably end up with more tools to play with in the shell.

Don't forget to copy the /lib/fireware and /lib/mod* directories from ubuntu to your gentoo install, or optionally extract the config.gz from /proc/config.gz, and grab the source to the ubuntu 13.10 kernel. Then do a "zcat /proc/config.gz > /usr/src/linux/.config" and a "make modules && make modules_install && make fireware && make fireware_install"

gpm doesn't know how to talk to the touchscreen, but it's there, in /dev/input/event0 ; and "less -f /dev/input/event0" shows data when you press the screen. Maybe xorg will have better support for it?
wpa_supplicant works
backlight dimming works (in /sys)
battery status shows up (in /sys)
didn't try bluetooth, but it should work, most anything that works on the ubuntu install should work, or work after proper set-up.

abootimg source, and kernel source can be gotten from the ubuntu project, just google it

Anywho, going to play with my gentoo install for a while, I've subscribed to this topic, so if you need help, post a question, and I'll drop by
_________________
echo deadram; fortune

[Shiggity]

Okay there're some things I don't quite understand.

1. Which N7 does this work on? The 2012 model? The 2013 model? Both?

2. Why does Ubuntu need to be installed first? Is there not a way to install Gentoo directly? I'd personally want Funtoo but the installation process is pretty much the same (stage 3 tarball and then go from there).

3. Is there a way to get this is all working on a Nexus 10? Its screen size and ultra-high resolution is enticing me. But its price is not. lol

I'd really like a more third party OS friendly tablet, as I don't own a laptop at the moment since it broke on me after 6 years last summer.

I currently have a 2011 release 'fire sale' model 32 GB HP TouchPad and a 2013 LG GPad 8.3. Both great devices, but none of them can easily run anything but their respective stock OSes well. I do own a Nexus 5, but I'd rather keep that my phone and only my phone, and not a tiny tablet. Its screen is too small to even attempt to do what I want to do with something like an N7.

Thanks,
Shiggity

[deadram]

[Shiggity]

[deadram]

Some more progress. Writing this from firefox 31.0. Apparently there is a bug in older firefox versions to do with arm processors, without neon support. I also spent a week trying to get the touchscreen to work, before going back to the old ubuntu kernel. Apparently that sorted it out, so it looks like I'll be stuck with that kernel for a while.Just built the xf86 open tegra drivers, since the tegra drivers from Nvidia only go to ABI11, and I think xorg was at 15 or so. Have yet to restart Xorg, but the fbdev drivers work fine anyways.

wmaker is running nice and smooth. apart from very tiny places to "click" with the touchscreen, I've yet to run into serious problems. Once xorg and xscreensaver where emerged, and I put 1 min timeout for the dpms setting, the battery problems went away..

I've still to finish emerging lighttpd and mysql, and a few other toys, play with kernels a bit more too. After that I'll get a "minimal cd image" prepared for people to do their own installs.

Have to say though, compared to my 10" netbook, this thing has much more desktop real-estate, if only xorg's evdev driver supported third button emulation on touchscreens. Another project for another day, I suppose.

EDIT --

Here's some screens

http://i.imgur.com/lJfhwlo.jpg
http://i.imgur.com/szuc1yd.jpg
_________________
echo deadram; fortune

[AaronPPC]

What an interesting project. I have had an Acer A100 for a couple of years, but lost interest in it after I found that it was not very hackable. This might get me interested in tablets again.
_________________
--Aaron

[deadram]

A little more progress. Turns out some of my kernel woes were from using the wrong "version". I managed to thin it out about as much as possible, without losing support for drivers. Most of the drivers require kernel options to compile, or to work, but they don't "force require" the options when doing a make [old/menu/gui]config. Also, the opentegra xorg driver won't work with the included GPU driver. - I'll have to hack the wifi, driver at least; it really likes debugging support in the kernel, but who needs that anyways? It's not like the kernel ever has bugs Anywho, - while I plug away at thining the wifi driver, I might try to add opentegra support too.

Can't seem to get an android adobe libflashplayer.so to work with mozilla (or apparently, libc) so html5 video is the only possibility for the forseeable future. mplayer2 seems to handle video just fine, except for zoom capabilities (which I expect the open tegra drivers to solve). Goes fine without fullscreen/maximize, but will slow to a crawl if it has to scale the video, and it only seems to be able to scale by doubling the pixels.

Also, the cpu driver can't boot unless the default cpu governor is "userspace", at least till /etc/init.d/local starts. I won't bother with that one though. Much easier to add a script to /etc/local.d to echo governor's into the /sys fs. Besides, I was playing risky altering the frequency so early in boot (by using ondemand,or such, as default).

Finally, you can boot without initramfs. My problem was that I would crash,once "syslog-ng|cronnie|xdm|local" was started by init. Turns out, if you add "consolefont" to the boot rc level, it will set the tty encoding (eg: utf- and this was the only important step in the ubuntu initramfs. That one took a few interactive boots into single-user, so I hope someone appriciates it, lol!

You's can expect a "CD" image eventually, but for another couple months you'll probably just have to hack it out yourself
_________________
echo deadram; fortune

[albright]

amazing progress on this, congrats

I wonder, do you have usb audio output working? (I can see turning
my old nexus 7 into a pretty good sound cenre)
_________________
.... there is nothing - absolutely nothing - half so much worth
doing as simply messing about with Linux ...
(apologies to Kenneth Graeme)

[deadram]

[ucbst]

My nexus 7 3g 2012 aka tilapia or nakasig has got a broken touch screen, so I use it on a daily basis with a bluetooth keyboard and console tools (vim, links, ranger etc) from an arch linux chroot where I ssh from a cyanogenmod environment.

Looking for a way to get a snappy X environment where I could work with multiple workspaces at the same time, I figured out a similar procedure to the one you describe, and managed to set up arch linux as a primary os.

Fastboot-flashed the ubuntu image, configured and backed it up, unpacked a clean archlinuxarm tarball into a chroot, installed a wpa_supplicant package, modified the boot partition with abootimg to mount my root fs read-write, booted my cwm recovery, and replaced ubuntu with arch through an adb shell. After a successful reboot, I connected to my network and installed a Xorg/framebuffer/openbox environment which seemed ok in terms of smoothness.

Unfortunately, my setup is useless without a keyboard. On ubuntu, I could get my keyboard to pair but it disconnected immediately. On arch with the ubuntu kernel, neither bluez 5 nor 4 saw any controllers at all. So I reinstalled android. This thread brought me a little more hope; maybe I could repeat your kernel building steps and get bluetooth to work on a real gnu/linux like it does on android?

I still have built no custom kernel and rely on the one from ubuntu. Could you please explain which steps you have taken to build a proper boot image with a gentoo kernel and initramfs? Is there a way for me to reproduce those steps on arch?

[deadram]

@ucbst

If bluetooth doesn't work in ubuntu, I doubt it will work anywhere else. The ubuntu team merged the nexus 7 specific stuff from the android kernel fork, into the vanilla kernel, but they never got everything working. I've tried to test bluetooth by installing bluez and looking for the host device, but no host devices are listed.

There are 2 possible options to get bluetooth working.

1) add the nexus 7 bluetooth code from the android forked kernel, into the ubuntu kernel. This would take time and effort, and some knowledge of the kernel source, and C.

2) Try to use a cyanogen or AOSP android forked kernel for the nexus7 to boot up *nix. I'm not sure if the android kernel will be able to manage to boot into a real OS, but if it does it should already come with the drivers needed for bluez, etc... to work.

What I did for my setup was to use the ubuntu kernel here: https://launchpad.net/ubuntu/+archive/primary/+files/linux-nexus7_3.1.10-10.28.tar.xz

I took the .config file from the proc file system when I was booted into ubuntu, and then thinned it out, removing kernel options and features I don't use. It wouldn't make a difference if you built this kernel, or used the ubuntu kernel, since I've simply removed the kernel options I consider "bloat", but here's the .config: https://drive.google.com/file/d/0B1Bl3m359MOdeGR4ZHR0QXhXSTA/view?usp=sharing

Keep in mind, you need to set the console font before starting any tty's, since my kernel doesn't use an initramfs (in abootimg I specify the ubuntu initramfs, but it's never loaded by my kernel). In gentoo you do this by adding "consolefont" to the boot rc run level. ie:

# rc-config add consolefont boot

PS: Sorry for the late reply., ask away if you need more help
_________________
echo deadram; fortune

[reanimus]

Are you still about? Any updates on it?

[deadram]

havn't been doing much with it, got an ota cable aand usb hub for keyboard and mouse, and figured out how to dual boot android with a bash script and teamwin recovery. working on a remote controle lawnmower atm. It's been stable enough, but you need to unmask a lot of packages, and every few updates you need to work extra hard to fix dependancy problems.
_________________
echo deadram; fortune

[steveL]

Nice work. Can we see that asoundrc you mentioned?

[reanimus]

Did you ever try using the gentoo-sources to try to boot with?

[deadram]

[reanimus]

Dang. I was hoping to go as Gentoo as possible. I'll see if I can get the gentoo-sources booting (and if I do, I'll post a config. )

Alternatively, did you ever figure out a good way to charge while the USB keyboard is plugged in? :S

[deadram]

[deadram]

sorry it took so long, google drive got an update that disables it unless you use chrome... or something... anyways
https://docs.google.com/file/d/0B1Bl3m359MOdc1BqelZ4M0dNS3c/edit?usp=docslist_api

should have my battery, cpufreq, and acpid scripts. It's up to yous to read them, and understand what each does

battery_mon I use with wmswallow on wmaker, It does a 5 min shutdown at 25% and a shutdown now at 5%... if I remeber correctly.

--- EDIT ---

Waiting on icedtea to finish it's second build, been about a day so far, but I did manage to get adb, and fastboot working. Used it to try to install ubuntu on a new nexus 4 I picked up (nexus 7 with gentoo and an OTA cable, using fastboot and adb to alter the nexus 4). By the by, don't bother trying the nexus 4 with ubuntu Anywho, might end up with gentoo on the poor thing, and hopefully a working phone in the end XD

Once icedtea finishes, I'll check to see if arduino and android sdk works too.

--- edit 2 ---

icedtea finished, but android sdk will have to wait till I figure out how to make a swt.jar arm file, and I forget what the latest arduino version was complaining about... by the by, to be OS independent, write good c/c++ code, not bloatware. gcc complies 4 times, before icedtea compiles once. Assuming you don't run into compile time problems... then add all the .jar dependancies, that are os dependant... ?!?!?! why is java even around anymore... ?!?!?!

anywho, nexus 4 has ubuntu/cyanogen dualboot. root you nexus 4, install cyanogenmod (so you don't have to update to android 5.x) get dual boot ubuntu working, boot into cyanogenmod, and from term 'null' the root password