Root on the LG 2X is easy. It's vulnerable to the psneuter exploit, after which su and Superuser APK can be pushed to a remounted system partition.
Partitions / Filesystems
The key partitions are as follows:
/dev/block/mmcblk0p1 = system partition
/dev/block/mmcblk0p2 = cache partition
/dev/block/mmcblk0p3 = misc partition
/dev/block/mmcblk0p4 = unknown partition
/dev/block/mmcblk0p5 = boot partition
/dev/block/mmcblk0p6 = lgdrm partition
/dev/block/mmcblk0p7 = recovery partition
/dev/block/mmcblk0p8 = data partition
/dev/block/mmcblk0p9 = internal SD partition
The kernel has support for EXT2/EXT3 filesystems (no EXT4 support). All of the key partitions are EXT3.
Partition sizes are as follows:
Boot image / recovery
/lgdrm: 2472K total
/system: 338924K total
/data: 1523328K total
/cache: 63472K total
/misc: 1976K total
/sdcard: 5773920K total
The 2X does have conventional boot and recovery images. The BOARD_KERNEL_BASE is 0x10000000 and the page size is 0x800. I have successfully reconstructed the boot image and flashed using 'dd' with no problems! The boot partition has a capacity of 8388608 bytes, which gives plenty of scope for doing clever stuff in the boot image.
The recovery partition is 20971520 bytes in size, which is unusually large. UPDATE: Holding down volume down + power throughout boot boots to recovery!
Memory available is as follows:
The kernel version on the ROM I am currently running (see below) is 18.104.22.168. The source for the kernel is not currently available, however LG have made the source available for the Korean version of the device (SU660) - I have yet to compile and test this on the P990.
Thankfully, CONFIG_IKCONFIG_PROC is enabled in the kernel so it's possible to view the kernel config - i've uploaded it to pastebin here
The device can be flashed in two main ways - using the standard LG flashing tool or using NVFlash. I have tested both methods. The images flashed using NVFlash do not appear to be signed. In addition, partitions can be flashed using the 'dd' method (I have tested this to overwrite the boot image).