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

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.

NEXT: RECOVERY.fstab