U-Boot for the LG X3 T30 device family

DISCLAMER! Moving your LG P880 or P895 to use U-Boot assumes replacement of the vendor LG bootloader. Vendor android firmwares will no longer be able to run on the device. This replacement IS reversible.

Quick Start

• Build U-Boot

• Pack U-Boot into repart-block

• Flash repart-block into the eMMC

• Boot

• Self Upgrading

Build U-Boot

Device support is implemented by applying config fragment to a generic board defconfig. Valid fragments are p880.config and p895.config.

$ export CROSS_COMPILE=arm-linux-gnueabi-
$ make x3_t30_defconfig p895.config # For LG Optimus Vu
$ make

After the build succeeds, you will obtain the final u-boot-dtb-tegra.bin image, ready for flashing (but check the next section for additional adjustments).

Pack U-Boot into repar-block

DISCLAMER! All questions related to re-crypt work should be asked in re-crypt repo issues. NOT HERE!

re-crypt is a small script which packs u-boot-dtb-tegra.bin in form usable by device. This process is required only on the first installation or to recover the device in case of a failed update.

$ git clone https://github.com/clamor-s/re-crypt.git
$ cd re-crypt # place your u-boot-dtb-regra.bin here
$ ./re-crypt.sh -d p895

Script will produce you a repart-block.bin ready to flash.

Flash repart-block into the eMMC

DISCLAMER! All questions related to NvFlash should be asked in the proper place. NOT HERE! Flashing repart-block will erase all your eMMC, so make a backup before!

repart-block.bin contains BCT and bootloader in encrypted state in form which can just be written RAW at the start of eMMC.

$ wheelie --blob blob.bin
$ nvflash --resume --rawdevicewrite 0 1024 repart-block.bin

Boot

After flashing repart-block.bin the device should reboot and turn itself off. This is normal behavior if no boot configuration is found.

To boot Linux, U-Boot will look for an extlinux.conf on MicroSD and then on eMMC. Additionally if Volume Down button is pressed while booting device will enter bootmenu. Bootmenu contains entries to mount MicroSD and eMMC as mass storage, fastboot, reboot, reboot RCM, poweroff, enter U-Boot console and update bootloader (check next chapter).

Flashing repart-block.bin eliminates vendor restriction on eMMC and allows the user to use/partition it in any way the user desires.

Self Upgrading

Place your u-boot-dtb-tegra.bin on the first partition of the eMMC (using ability of u-boot to mount it). Enter bootmenu, choose update bootloader option with Power button and U-Boot should update itself. Once the process is completed, U-Boot will ask to press any button to reboot.