You can currently use Omni 4.3, Omni 4.4, CM7, CM9, CM10.0, CM10.1, CM10.2, and CM11.0 source code. Omni 4.4 is recommended. CM9 and older will not be able to support SELinux for installing 4.4 ROMs.
If you are using CM, you'll need to replace CM/bootable/recovery with this:
Select the newest branch available. This step is not necessary with Omni because Omni already includes TWRP source by default.
*FOR CM7 ONLY*
Replace the entire CM7/build folder with this:
Make sure that you get the twrp2.3 branch and *not* the master branch.
*BEFORE YOU COMPILE*
Note: If you add or change any flags, you will need to make clean or make clobber before recompiling or your flag changes will not be picked up.
Now that you have the source code, you'll need to set or change a few build flags for your device(s). Find the BoardConfig.mk for your device. The BoardConfig.mk is in your devices/manufacturer/codename folder (e.g. devices/lge/hammerhead/BoardConfig.mk). First, scan the BoardConfig.mk file for
If your device has this line, it will have a path to a custom, prebuilt init.rc that is used in recovery. Most likely you will need to change the custom init.rc slightly. Find the recovery's init.rc file and open it. Near the top you will see something like this:
on init export PATH /sbin export LD_LIBRARY_PATH .:/sbin
Your board config also needs to include architecture and platform settings. Usually these are already included if you're using device configs that someone else created, but if you created your own, you may need to add them. Without them, recovery may seg fault during startup and you'll just see the teamwin curtain flash on the screen over and over.
We usually put all of our flags at the bottom of the BoardConfig.mk under a heading of #twrp For all devices you'll need to set a resolution. TWRP needs to know the resolution at compile time so that it knows what stock theme to include. You can only use resolutions that have a theme so if you don't see your resolution, you'll have to pick one that's less than or equal to your resolution. You can find the list of stock themes in bootable/recovery/gui/devices. So if your device has a 540x960 display, you would add this:
DEVICE_RESOLUTION := 540x960
Note that themes do not rotate, so the 1280x800 theme is intended for tablets and would not work on the Samsung Galaxy Note that expects a 800x1280 type of theme.
In addition to the resolution, we have the following build flags:
RECOVERY_SDCARD_ON_DATA := true -- this enables proper handling of /data/media on devices that have this folder for storage (most Honeycomb and devices that originally shipped with ICS like Galaxy Nexus)
RECOVERY_GRAPHICS_USE_LINELENGTH := true -- fixes slanty looking graphics on some devices
BOARD_HAS_NO_REAL_SDCARD := true -- disables things like sdcard partitioning and may save you some space if TWRP isn't fitting in your recovery patition
TW_INCLUDE_DUMLOCK := true -- includes HTC Dumlock for devices that need it
This is how you would define dual storage for devices that have dual storage devices. For devices that have internal storage we usually define that as /emmc. Note that the mount point must match something in the recovery.fstab These flags are somewhat deprecated in TWRP 2.5+ but they are still used for a few things.
TW_INTERNAL_STORAGE_PATH := "/data/media"
TW_INTERNAL_STORAGE_MOUNT_POINT := "data"
TW_EXTERNAL_STORAGE_PATH := "/sdcard"
TW_EXTERNAL_STORAGE_MOUNT_POINT := "sdcard"
TW_NO_BATT_PERCENT := true -- disables the display of the battery percentage for devices that don't support it properly
TW_CUSTOM_POWER_BUTTON := 107 -- custom maps the power button for the lockscreen
TW_NO_REBOOT_BOOTLOADER := true -- removes the reboot bootloader button from the reboot menu
TW_NO_REBOOT_RECOVERY := true -- removes the reboot recovery button from the reboot menu
TW_NO_USB_STORAGE := true -- removes the USB storage button on devices that don't support USB storage
RECOVERY_TOUCHSCREEN_SWAP_XY := true -- swaps the mapping of touches between the X and Y axis
RECOVERY_TOUCHSCREEN_FLIP_Y := true -- flips y axis touchscreen values
RECOVERY_TOUCHSCREEN_FLIP_X := true -- flips x axis touchscreen values
TW_ALWAYS_RMRF := true -- forces the rm -rf option to always be on (needed for some Motorola devices)
TW_NEVER_UNMOUNT_SYSTEM := true -- never unmount system (needed for some Motorola devices)
TW_INCLUDE_INJECTTWRP := true -- adds ability to inject TWRP into some Samsung boot images for Samsung devices that have recovery as a second ramdisk in the boot image
TW_DEFAULT_EXTERNAL_STORAGE := true -- defaults to external storage instead of internal on dual storage devices (largely deprecated)
TWRP_EVENT_LOGGING := true -- enables touch event logging to help debug touchscreen issues (don't leave this on for a release - it will fill up your logfile very quickly)
Here's some flags that may help you, but are not specific to TWRP (works in CWM too):
This flag has multiple options, but can be used to set different graphics modes that may be need to correct color space issues on some devices:
TARGET_RECOVERY_PIXEL_FORMAT := "BGRA_8888"
TARGET_RECOVERY_PIXEL_FORMAT := "RGBX_8888"
TARGET_RECOVERY_PIXEL_FORMAT := "RGB_565"
BOARD_HAS_FLIPPED_SCREEN := true -- flips the screen upside down for screens that were mounted upside-down
TARGET_PREBUILT_RECOVERY_KERNEL := path/to/kernel -- use to specify a kernel specifically for building recovery
TWRP 2.5 and higher supports some new recovery.fstab features that you can use to extend TWRP's backup/restore capabilities. You do not have to add fstab flags as most partitions are handled automatically.
Note that TWRP does not currently support the "fstab 2" version of fstab files seen in 4.3 or higher. You will still need to use the "old" format of fstab for TWRP (example of that format is below). To maximize TWRP's compatibility with your build tree, you can create a twrp.fstab and use PRODUCT_COPY_FILES to place the file in /etc/twrp.fstab When TWRP boots, if it finds a twrp.fstab in the ramdisk it will rename /etc/recovery.fstab to /etc/recovery.fstab.bak and then rename /etc/twrp.fstab to /etc/recovery.fstab. Effectively this will "replace" the fstab 2 file that your device files are providing with the TWRP fstab allowing you to maintain compatibility within your device files and with other recoveries.
PRODUCT_COPY_FILES += device/lge/hammerhead/twrp.fstab:recovery/root/etc/twrp.fstab
Here's a sample TWRP fstab for the Galaxy S4 that we will use for reference:
/boot emmc /dev/block/platform/msm_sdcc.1/by-name/boot /system ext4 /dev/block/platform/msm_sdcc.1/by-name/system /data ext4 /dev/block/platform/msm_sdcc.1/by-name/userdata length=-16384 /cache ext4 /dev/block/platform/msm_sdcc.1/by-name/cache /recovery emmc /dev/block/platform/msm_sdcc.1/by-name/recovery /efs ext4 /dev/block/platform/msm_sdcc.1/by-name/efs flags=display="EFS";backup=1 /external_sd vfat /dev/block/mmcblk1p1 /dev/block/mmcblk1 flags=display="Micro SDcard";storage;wipeingui;removable /usb-otg vfat /dev/block/sda1 /dev/block/sda flags=display="USB-OTG";storage;wipeingui;removable /preload ext4 /dev/block/platform/msm_sdcc.1/by-name/hidden flags=display="Preload";wipeingui;backup=1 /modem ext4 /dev/block/platform/msm_sdcc.1/by-name/apnhlos /mdm emmc /dev/block/platform/msm_sdcc.1/by-name/mdm
/external_sd vfat /dev/block/mmcblk1p1 flags=display="Micro SDcard";storage;wipeingui;removable
removable -- indicates that the partition may not be present preventing mounting errors from being displayed during boot
storage -- indicates that the partition can be used as storage which makes the partition available as storage for backup, restore, zip installs, etc.
settingsstorage -- only one partition should be set as settings storage, this partition is used as the location for storing TWRP's settings file
canbewiped -- indicates that the partition can be wiped by the back-end system, but may not be listed in the GUI for wiping by the user
userrmrf -- overrides the normal format type of wiping and only allows the partition to be wiped using the rm -rf command
backup= -- must be succeeded by the equals sign, so backup=1 or backup=0, 1 indicates that the partition can be listed in the backup/restore list while 0 ensures that this partition will not show up in the backup list.
wipeingui -- makes the partition show up in the GUI to allow the user to select it for wiping in the advanced wipe menu
wipeduringfactoryreset -- the partition will be wiped during a factory reset
ignoreblkid -- blkid is used to determine what file system is in use by TWRP, this flag will cause TWRP to skip/ignore the results of blkid and use the file system specified in the fstab only
retainlayoutversion -- causes TWRP to retain the .layoutversion file in /data on devices like Sony Xperia S which sort of uses /data/media but still has a separate /sdcard partition
symlink= -- causes TWRP to run an additional mount command when mounting the partition, generally used with /data/media to create /sdcard
display= -- sets a display name for the partition for listing in the GUI
storagename= -- sets a storage name for the partition for listing in the GUI storage list
backupname= -- sets a backup name for the partition for listing in the GUI backup/restore list
length= -- usually used to reserve empty space at the end of the /data partition for storing the decryption key when Android's full device encryption is present, not setting this may lead to the inability to encrypt the device
canencryptbackup= -- 1 or 0 to enable/disable, makes TWRP encrypt the backup of this partition if the user chooses encryption (only applies to tar backups, not images)
userdataencryptbackup= -- 1 or 0 to enable/disable, makes TWRP encrypt only the userdata portion of this partition, certain subfuldes like /data/app would not be encrypted to save time
subpartitionof= -- must be succeeded by the equals sign and the path of the partition it is a subpartition of. A subpartition is treated as "part" of the main partition so for instance, TWRP automatically makes /datadata a subpartition of /data. This means that /datadata will not show up in the GUI listings, but /datadata would be wiped, backed up, restored, mounted, and unmounted anytime those operations are performed on /data. A good example of the use of subpartitions is the 3x efs partitions on the LG Optimus G:
/efs1 emmc /dev/block/mmcblk0p12 flags=backup=1;display=EFS /efs2 emmc /dev/block/mmcblk0p13 flags=backup=1;subpartitionof=/efs1 /efs3 emmc /dev/block/mmcblk0p14 flags=backup=1;subpartitionof=/efs1
If you have questions, feel free to stop by #twrp on Freenode. If you post here I may not see it for a while as I have lots of threads out there and there's no way for me to keep track of them all. If you successfully port TWRP to a new device, please let us know! We love to hear success stories!
If you have code changes that you'd like to submit, please submit them through the Omni Gerrit server. Guide is here.
Once you get Omni or CM sync'ed and your TWRP flags set, you should do a source ./build/envsetup.sh We usually lunch for the device in question, so something like "lunch omni_hammerhead-eng".
After you lunch successfully for your device this is the command used for most devices:
make clean && make -j# recoveryimage
make -j# bootimage
Notes about 4.4 Kit Kat ROMs and SELinux
There's absolutely no SELinux support in ICS trees or older. libselinux is not included in these trees and some dependencies for libselinux don't exist elsewhere in these older trees so there's no way to get SELinux support unless you move to a newer tree. I recommend using a 4.3 based tree or higher.
SELinux support is included in all builds of TWRP so long as you build in a tree that has libselinux present. However, for SELinux support to work, your kernel must support EXT4 security labels as well. If you're using an older kernel, your TWRP won't support SELinux and you will get errors when installing 4.4 Kit Kat ROMs due to set_metadata not being able to set SELinux contexts. You'll see an error in the recovery log stating something along the lines of "Operation not supported on transport endpoint." This means you need to add proper support to the kernel you are using in recovery. (Yes, at least in most cases, recovery has its own kernel.)
In the kernel source I was testing, the needed flag was CONFIG_EXT4_FS_SECURITY=y and the option was called Ext4 Security Labels under the file systems menu. If you want full SELinux in your kernel you will need to add auditing support (usually found under general setup) then enable SELinux under security options. There's multiple flags and some dependencies involved so your setup may vary slightly.
The android-4.4 branch of TWRP from Omni now includes a check during boot. You will see text in the log and in the console indicating the SELinux status. This should help you identify what issue(s) you may have with SELinux support.
Deprecated build flags:
For TWRP < 2.5:
The below is how you can add custom / special partitions to the list of partitions available for backup. The SP1_NAME must match the name of a partition defined in recovery.fstab. The SP1_DISPLAY_NAME is the name displayed on the backup page if it needs to be different than SP1_NAME. SP1_BACKUP_METHOD defines how the partition should be backed up (files or image). And SP1_MOUNTABLE determines if the partition can be mounted.
SP1_NAME := "pds"
SP1_BACKUP_METHOD := files
SP1_MOUNTABLE := 1
SP2_NAME := "osh"
SP2_DISPLAY_NAME := "Webtop"
SP2_BACKUP_METHOD := files
SP2_MOUNTABLE := 1
SP3_NAME := "preinstall"
SP3_BACKUP_METHOD := image
SP3_MOUNTABLE := 0