[LG Optimus 4X HD] laufersteppenwolf:
As you can see in the title, i decided to write a small fastboot tut, especially for our p880 and its "own" commands and tricks ;)

I am, as always, not responsible for what you do with your device. Do it on your own risk.

I will however not explain on how to set up fastboot on your PC. There are tons of tuts out there on xda, just search for it ;)

NOTICE: You need an unlocked bootloader for this

Screenshots will be added later, 'cause my lappy is compiling right now and i thought i could use the time to write this ;) so just wait a bit

Now, lets begin with the fun, shall we? :D

General

Fastboot is usually quite easy to use. But if you went searching for a tut on the web, you might have noticed that it doesn't work the way it should on your device.

That's because LG messed something up in the bootloader, but let's don't worry about that now, it does work nontheless ;)

Fastboot is "a part" of the bootloader. This means, neither the kernel (boot), nor the recovery gets booted.

That gives you the ability to flash, but also boot kernels/recoveries. And yes, i meant booting, without really flashing it :p

Now we need to get into fastboot mode:

And this is (one of) the point(s) where LG messed up. The usual command is "adb reboot bootloader". But this command does not work on your device the way it should.

It gets you into a kind of fastboot mode, but you can't flash anything, because it says the bootloader would be locked, even tho it isn't.

The working command is

adb reboot oem-unlock

i guess this command sounds familliar, doesn't it? :p and don't worry, it will not lead you to a menu that deletes your data.

It will lead you to the working fastboot mode ;)

now we're in the working fastboot mode. To check if you've set up fastboot correctly, type

fastboot devices

this should list your phone and its serial number.

It is recognized? good. so now we might want to check the status of our device (BL unlock state, serial number,...).

Therefore type

fastboot getvar all

now you can check whether it's really unlocked or not.

If everything's fine, you might want to...

Flash something

In order to flash something, you need the appropriate image. For kernels it's mostly "boot.img"

The command to flash something via fastboot is in general

fastboot flash <partition> <filename>

Example: You want to flash a kernel (named test_boot.img) and you have downloaded the kernel to the folder where your fastboot.exe is.

So you type

fastboot flash boot test_boot.img

This will copy the kernel to your device and then flash it to the LNX (boot) partition.

Of course you can flash other partitions, too, like system, data, cache, recovery...

After a flash, it is wise to clear the cache, or even your /data partition...

Deleting a partition

You don't need a recovery to wipe a partition, just use fastboot ;)

The general command is

fastboot erase <partition>

For our example it's enough to wipe the cache. You can do this using this command:

fastboot erase cache

Also here you can wipe all partitions, like system, data, cache, boot, recovery...

So now we've flashed what we wanted to, wiped the needed partitions, but how do i..

Get out of fastboot

This is as easy as getting in ;) just type

fastboot reboot

to reboot the device (Here's another thing, where LG messed up.... it reboots, but stays at the LG spash screen.

So press the power button for at least 10 secs. Now your device will reboot into recovery (!?) :confused:

then just tap reboot system now and be happy ;) )

or

fastboot continue

this one will not reboot the device, but continue the boot procedure. I, for one, would suggest you to use the first command

now your device will boot up normally (except your kernel/system.... has a bug of course :p )

for more help, just type

fastboot help

and the last point is...

Bricking the device

nah, just kidding :p​