yesterday's OTA firmware update to my CAT B15Q (CPU MediaTek MT6582M) showed an error similar to "failed to update metadata symlink" and offered me to reboot... since then the device is stuck in a bootloop and only boots recovery and fastboot.
The recovery console doesn't offer any USB devices, except when choosing "apply update from ADB", upon which adb devices lists it as "0123456789ABCDEF sideload". adb shell however does not work, it gives an "error: closed" message.
Resetting to factory did not help either, current Android version of the device was 4.4.2.
By the looks, the failed update bricked the /system somehow; can I sideload a version of adb onto the recovery to gain shell access?