Google Nexus 7 2013 (asus-flo)

Contributors

 * David Heidelberg (okias) -> trying to work on maintaining latest LTS kernel...
 * montvid porting (not active)
 * John Stultz Flo kernel patches maintainer (not active)
 * Rob Clark Freedreno video driver maintainer (not active)

Key combinations

 * Boot to bootloader: Power + Volume Down
 * Boot to recovery: Power + Volume Up
 * Shutdown: Power

Hardware revisions
First figure out, which HW revision do you have. You can do that from booted TWRP or original AOSP kernel by running

Alternatively from bootloader (fastboot), run

Known hardware revisions are: * rev_e * ??

Note: at present, the hardware revision does not seem to be of any consequence.

How to enter flash mode

 * Connect a USB cable
 * Power the device off
 * Hold  +
 * should work when the green android appears on the screen

Installation process
Is currently identical to Google_Nexus_7_2012_(asus-grouper), just beware, that DATA partition numbers can differ!

Mainline status

 * 4.11 kernel with many workarounds works
 * 4.12-rc1 broke Adreno, not fixed at least until kernel 5.6 https://github.com/freedreno-zz/freedreno/issues/12
 * 4.14 kernel running, but when 3D or Xserver is used, it tends to stop working.
 * 5.4 - working
 * 5.10 (LTS) - currently being worked on, sometimes laggy touchscreen
 * 5.11 - 5.12 needs power button shortly pressed in initial booting process
 * mainline and -next should be working with correct configuration

Issues (WIP)
sudo wpa_supplicant -u -Dnl80211 -B -c/etc/wpa_supplicant/wpa_supplicant.conf -iwlan0 sudo nmcli device wifi connect "ssd" password "pass" ifname wlan0
 * WIFI firmware sometimes does not load on boot. WIFI connection is very slow - probably to the wcn36xx driver still being a work in progress. You need to start WiFi as the firmware loads late in the boot process.

Other information
./pmbootstrap.py flasher flash_rootfs --partition userdata ./pmbootstrap.py flasher flash_kernel
 * Flash the system to a userdata partition to have 10GB free space. If you don't see 10GB install TWRP recovery and format system/all partitions and start again:


 * When I tried flashing rootfs, it would fail almost immediately after erasing. I installed TWRP, and tried a few things to "wipe" it, which worked, and then permitted the good flash (with hildon UI) below.  (Note that, although the instructions for TWRP 3.2.2-0 for asus-flo suggest that you might need to do "fastboot reboot" and then hold down the buttons, that only resulted in what appeared to be boot loops of TWRP -- what worked instead was to use the buttons to power off, and then use the buttons to boot recovery.)

(native) flash rootfs image target didn't report max-download-size erasing 'userdata'... OKAY [ 0.977s] sending 'userdata' (395264 KB)... OKAY [395.414s] writing 'userdata'... OKAY [ 19.449s] finished. total time: 415.840s


 * When I tried flashing with the Hildon UI (on 2018-07-27), it booted to the blue Hildon wallpaper, but the wallpaper only filled a square subset of the display.


 * For unknown reasons, I'm seeing rootfs flash times that seem slow. For example, a flash of plasma-mobile ui (808 MB) took 850.323s, with 808.169s of that in sending phase.  This is approx. 10 times the duration for flashing sony-amami from the same laptop.


 * I would recommend installing and using MATE as it is very complete
 * To run Internet via USB see USB Internet


 * Correct battery charge info appears to be in: /sys/bus/i2c/drivers/bq27xxx-battery/0-0055/power_supply/bq27541-0/charge_now


 * It's possible that Nexus 7 2013 units have flash hardware problems: AndroidPolice.com 2015-04-19, appleinsider.com 2013-06-18

Links

 * Device package
 * Kernel package
 * TWRP recovery
 * WIFI start with Wcnss-start
 * John Stultz's Flo kernel/patches
 * Rob Clark's Freedreno video driver
 * Making the UART Cable for Flo