[Galaxy Tab 3 General] ketut.kumajaya:
KitKat update for Tab 3 8.0​

T310:

http://www.sammobile.com/firmwares/1/?page=1&model=SM-T310&pcode=0#firmware

http://samsung-updates.com/device/?id=SM-T310

T311:

http://www.sammobile.com/firmwares/1/?page=1&model=SM-T311&pcode=0#firmware

http://samsung-updates.com/device/?id=SM-T311

T315:

http://www.sammobile.com/firmwares/1/?page=1&model=SM-T315&pcode=0#firmware

http://samsung-updates.com/device/?id=SM-T315

Kernel cmdline from KitKat bootloader:

console=ram loglevel=4 sec_debug.level=0 sec_watchdog.sec_pet=5 androidboot.debug_level=0x4f4c sec_log=0x200000@0x46000000 sec_tima_log=0x200000@0x46202000 sec_avc_log=0x40000@0x46404000 s3cfb.bootloaderfb=0x5ec00000 lcdtype=2049 consoleblank=0 lpj=3981312 vmalloc=176m oops=panic pmic_info=67 cordon=00000000000000000000000000000000 connie=SM-T311_OPEN_EUR_00000000000000000000000000000000 androidboot.emmc_checksum=3 androidboot.odin_download=1 androidboot.bootloader=T311XXXXXXX androidboot.selinux=enforcing androidboot.warranty_bit=0 androidboot.sec_atd.tty=/dev/ttySAC2 androidboot.serialno=0000000000000000 snd_soc_core.pmdown_time=1000

Kernel cmdline from JellyBean bootloader:

console=ram loglevel=4 sec_debug.level=0 sec_watchdog.sec_pet=5 androidboot.debug_level=0x4f4c sec_log=0x200000@0x46000000 s3cfb.bootloaderfb=0x5ec00000 lcdtype=2049 consoleblank=0 lpcharge=0 lpj=3981312 vmalloc=176m oops=panic pmic_info=67 cordon=00000000000000000000000000000000 connie=SM-T311_OPEN_EUR_00000000000000000000000000000000 androidboot.emmc_checksum=3 androidboot.odin_download=1 androidboot.bootloader=T311XXXXXXX androidboot.serialno=0000000000000000 snd_soc_core.pmdown_time=1000

Boot to LPM from KitKat bootloader:

In low power mode (LPM, low power charging), "androidboot.mode=charger" string added to kernel cmdline, with this string the init process will trigger "charger" action group in init.rc and init.<platform>.rc.

Boot to LPM from JellyBean bootloader:

In LPM, "lpcharge=1" string added to kernel cmdline, kernel parse this string and via a sysfs tell the init process to load lpm.rc

JellyBean/CM based ROM/kernel with KitKat bootloader:

No "lpcharge=1" string from the bootloader in LPM, no command from the kernel to load lpm.rc, kernel patch needed. Even with patched kernel, with "androidboot.mode=charger" in kernel cmdline, the init process avoid "early-fs" and "boot" actions group in lpm.rc, playlpm service not get started. Patch to lpm.rc needed.

KitKat based ROM/kernel with JellyBean bootloader:

No "androidboot.mode=charger" string from the bootloader in LPM, "charger" action group in init.rc and init.<platform>.rc not get triggered, lpm service not get started. Even with patched kernel, in KitKat the init process not aware to lpm.rc anymore. Kernel cmdline or init.rc hijacking before the init process started needed.

Root:

For me, the easiest method is flash NEXT kernel for T31x using Heimdall on a Linux host. Boot your device to download mode, connect it to your computer, and then run Heimdall.

sudo heimdall flash --BOOT boot.img

Install SuperSU from Play Store. KNOX popup disabler included in the latest SuperSU or manually using "pm disable com.sec.knox.seandroid" command as root.

User apps permission to write external SD card fix included in NEXT kernel as a patch, auto merged on boot if necessary.

Unofficial recovery:

As above, flash PhilZ Touch recovery for T31x using Heimdall.

sudo heimdall flash --RECOVERY recovery.img

FUSION package from NEXT kernel thread more friendly for Windows user. NEXT kernel, PhilZ Touch recovery, and needed blobs in one Odin flashable package.

More info later.

FOLLOW THIS INSTRUCTION AT YOUR OWN RISK!