You can currently use Omni 4.4, Omni 5.1, Omni 6.0, CM11.0, CM 12.1, or CM 13.0 source code. Omni 5.1 or Omni 6.0 is recommended. Lately CM keeps making changes that make building TWRP more difficult and they make no effort to work with TWRP. You can build in CM but you may run into a few minor issues. If you don't know how to fix make file issues, then you should choose to use Omni instead.
If you are using CM, you'll need to place TWRP in the CM/bootable/recovery-twrp folder and set RECOVERY_VARIANT := twrp in your BoardConfig.mk file. TWRP source code can be found here:
Select the newest branch available. This step is not necessary with Omni because Omni already includes TWRP source by default, however, if you are using an older version of Omni, you will probably want to pull from the latest branch (the latest branch will compile successfully in older build trees)
If you are only interested in building TWRP, you may want to try working with a smaller tree. You can try using this manifest. It should work in most cases but there may be some situations where you will need more repos in your tree than this manifest provides:
*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).
Your board config will need 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 tell TWRP what theme to use. This TW_THEME flag replaces the older DEVICE_RESOLUTION flag. TWRP now uses scaling to stretch any theme to fit the screen resolution. There are currently 5 settings which are: portrait_hdpi, portrait_mdpi, landscape_hdpi, landscape_mdpi, and watch_mdpi. For portrait, you should probably select the hdpi theme for resolutions of 720x1280 and higher. For landscape devices, use the hdpi theme for 1280x720 or higher.
TW_THEME := portrait_hdpi
Note that themes do not rotate 90 degrees and there currently is no option to rotate a theme. If you find that the touchscreen is rotated relative to the screen, then you can use some flags (discussed later in this guide) to rotate the touch input to match the screen's orientation.
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) This flag is not required for these types of devices though. If you do not define this flag and also do not include any references to /sdcard, /internal_sd, /internal_sdcard, or /emmc in your fstab, then we will automatically assume that the device is using emulated storage.
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_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
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)
BOARD_HAS_FLIPPED_SCREEN := true -- flips the screen upside down for screens that were mounted upside-down
There are other build flags which you can locate by scanning the Android.mk files in the recovery source. Most of the other build flags are not often used and thus I won't document them all here.
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
Old guide here: http://forum.xda-developers.com/show...postcount=1471