[Thinkpad Tablet General] Ameisentaetowierer:
Hi ovecka,

so it looks like the partition containing BCT can't be written, maybe because of a hardware error?

The ROM you're using is trying to completely format every part of your SDRAM, not only the parts it really needs.

When this happens, it also tries to format the BCT....and dies....

I'll try to show a way to flash a ROM without formatting everything.

BTW: In my previous post I was wrong about the size that can be read by using rawdeviceread.

It's 4096 b per block, not 4096 k

I'm not sure, how many of the BCT partition is used on your device (partition size is 4194304 bytes) .

On my device I think it is 4080 bytes.

Now you may wonder, from where I know that it is only 4080 bytes?

There was an official update to ICS for my device. In this update was a file named "blob".

The ICS update flashed the blob to partition "USP".

On the next reboot the tablet stated: "updating BCT, updating EBT"

I found a tool to split the "blob" into BCT and EBT.

The size of the BCT file was 4080 bytes. So I think that it's only 4080 bytes.

But I don't know if it "grows", when the tablet updates the BCT on it's own.

If your BCT and EBT are correct, there's no need to format/flash them every time you want to flash a new ROM.

If you definitely want to try the blob from the ICS update, please have a look at the end of this post.

But how can you flash a ROM without formating BCT?

If you have a look at Yves pretty image (http://www.avi-plus.com/media/kunena/attachments/211/partitions_LT-P9516.png), you'll see, that your tablet contains several partitions.

The most interesting for flashing are:

SOS - here goes your stock recovery, or even better, CWM recovery image

LNX - here goes your boot image (mostly named boot.img), that contains the kernel and a RAM-filesystem

APP - this is an ext4 formatted filesystem cotaining your /system

UDA - your user data in /data - contains also /sdcard, which is the same as /data/media

CAC - your /cache partition

SOS and LNX are both images that can be flashed using nvflash. They both contain a packed linux kernel and a RAM-filesystem.

Think of them as selfextracting executables.

Sometimes APP is also stored as an image into a ROM-zipfile. But most times it is a subdirectory in the zipfile named "/system"

If it is an image, you can also write it using nvflash. If it is a subdirectory, you should "flash" (it is not flashing!) it using CWM.

UDA must be formatted. This can be done using CWM. Unfortunately the formatting in CWM is not the same as in Windows.

It's more like a factory reset, because it will keep /sdcard and deletes all other files.

But if the filesystem on UDA has been corrupted, you'll need the real (hard) format.

I've created a small zip, that can be "flashed" using CWM and which will hard format UDA (download here: https://mega.co.nz/#!x9t3xLBI!jOwSF7WuuP-Go2czgTMx2VDeruTYZ0fq6j0_6ki7umE)

CAC can be (hard) formatted using CWM.

If you want flash a single partition using nvflash, you should ensure, that the file containing the image has a size that can be divided by 4096.

For nvflash you have to specify the target block and the number of blocks (filesize divided by 4096) that you want to flash.

Most ROMs contain the boot.img for LNX and a /system folder for APP.

These ROMs can be installed using CWM.

Sometimes a ROM contains several partitions like SOS, LNX, APP and sometimes even a partition for UDA.

Then you can use nvflash to flash the partitions you are interested in (LNX and APP) directly, without completely formating SDRAM (and BCT, that leads to your problem)

There's no need to flash SOS (you can keep your CWM) or flash UDA (you can "format" it using CWM).

You just have to know how it works, then you can decide how to use it.

FLASHING A NEW BCT AND EBT

THIS MAY BRICK YOUR DEVICE!

I'm not sure, if it will also work on your tab.

But you can give it a try....do this on your own risk!!!!

Please backup partition BCT (just as much as you can read) and partition EBT first.

Then download the blob from here(https://mega.co.nz/#!Iskh2bIZ!r7Fbueg4aKydLy9Yr8TZUNjtrvDPjg_MU9z3CQ3Pp2g)

And write it to the USP partition, which should be located at sector 147456. Size of the file is 616 blocks.

nvflash --rawdevicewrite 147456 616 blob --odmdata 0x300c0011 --blob blob.bin --bl bootloader.bin --go

After rebooting, the tablet should show a message like "updating BCT ...."

If you can get the both partitions from someone here who has backed them up using rawdeviceread or just read, then you can try to flash them directly.