Allwinner-Tablet N8000 / PH_GT90h_android4.4_V2.0_800x480-auto-gc0308-0308-wifi5990p-20140627
TWRP recovery build guide http://forum.xda-developers.com/showthread.php?t=1943625
Run following commands
adb push recovery.img /sdcard/
adb shell "cat /sdcard/recovery.img > /dev/block/nandg; sync"