@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-Inte ... b+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.
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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
