Basically I just wanted to have my Titanium Backup working again after the OTA-Update…
This insecure boot image was created from factory image nakasi-jop40c-factory-6aabb391.tgz;
build number JOP40C.
It requires the “Google Nexus 7 ADB Interface” to be installed
and a unlocked boot-loader – just assuming both is given.
First, open a MS-DOS prompt and boot the device into the bootloader menu:
adb reboot bootloader
To download the image-file and boot it once (it’s rather not recommend to flash it):
fastboot boot boot-insecure-jop40c-nakasi.img
downloading 'boot.img'... OKAY [ 0.656s] booting... OKAY [ 0.016s] finished. total time: 0.672s
The device should boot until the X is displayed, no further.
Next, to remount the system partition read/write:
adb shell mount -o rw,remount -t ext4 /dev/block/platform/sdhci-tegra.3/by-name/APP /system
To install su & busybox (after further updates it’s ordinary enough to push/chmod su only):
adb push su /system/bin adb push SuperSU_0.98.apk /system/app/ adb push busybox /system/xbin/ adb shell chmod 06755 /system/bin/su adb shell chmod 0644 /system/app/SuperSU_0.98.apk adb shell chmod 04755 /system/xbin/busybox
And finally, just reboot.
adb shell reboot
But honestly, that the update would improve stability in any way was not the case… WiFi kept crashing and causing random reboots – going to revert to Android v4.1.x if this issue has not been fixed in Android v4.2.2, because the ConnectivityService is quite an essential service. This issue persisted on stock-images – and someone reported that the lag got worse with more than one user-account added. Indeed the worst update ever – probably it should have been tested more thoroughly *before* the release. Seems like they needed to release the multi-user environment before Apple does. Update: Haven’t noticed any further crashes since then, probably the WiFi profiles were incompatible?
XDA-Developers – 4.2 random reboots