[How-To] Rollback on old FW...

[ji035453]

Nice work

[erdem_ua]

Hi chris, I deleted some post and yours too since quoted....

I think your problem is finding exact ID right?
I guess: SWU_t-CHLDEUC_002004_IO2_ES000DS000_090816
is not right.
This lines from wiki:

Code: Select all

# mkdir /dtv/test1
# mkdir /dtv/test2
# mount -t auto /dev/tbml8 /dtv/test1
# /bin/busybox egrep -e 'T-CHL7DEUC-[0-9][0-9][0-9][0-9].[0-9]' /dtv/test1/exeDSP
SWU_T-CHL7DEUC_003000_I02_EK000DK000_100125
# mount -t auto /dev/tbml10 /dtv/test2
# /bin/busybox egrep -e 'T-CHL7DEUC-[0-9][0-9][0-9][0-9].[0-9]' /dtv/test2/exeDSP
SWU_T-CHL7DEUC_002004_I02_ES000DS000_090816

With this commands you can find your exact Firmware number to used to create Version.0 file.
(Your Version.0 file is created by you I think. Update it via exact ID of your older firmware)

After you can revert older firmware via TV's menu.

[gchirtoaca]

Hi,

Big bad news here, I've tried to downgrade firmware from T-CHLCIPDEUC 2007.1 to 2006.0 according to the famous "Forced revert back to older firmware" thread,
BUT BRIKED MY TV!
I did it all like it said there, and now TV starts, seems to work OK, but it shuts down automatically after aprox. 1 minute. It's probably the dreaded autld process that verifies the signatures. Also, the Upgrade software menu is dimmed and cannot be accessed again.
I've tried to input the "prevent restart" command, MicomCtrl 23, no joy. Running RSA diabler doesn't help. Killing exeDSP just freezes it completely.
Please help me find a fix fast. Imagine me explaining this to my wife!

[edelfalke]

what you have done exactly?

You can write a script (for example change the partitions) and start it while tv starts up.

[gchirtoaca]

What I've done:

- decrypted the 2006.0 firmware
- got version_info.txt with content "SWU_T-CHLCIPDEUC_002006_I02_ES000DS000_091112" and renamed it to Version.1 (already got Version.0 on /mtd_rwarea)
- copied the 2 images and Version.1 file over to USB stick
- put stick into TV and bml.restore'd the 2 images to partitions 10 and 11 (8 and 9 where the ones already used)
- entered the Menu->Upgrade, reverted to 2006.0
- the TV restarted and ... it keeps shutting down after this...

I have access to the SSH less than 1 minute (after manually starting SamyGo extensions).
How do I switch partitions? I've tried mounting 8 and 9 over the 10 and 11 (the ones used now) with no luck.

Edit: Well, now I see this procedure was available only for CI devices, and I have CI+...stupid me...
Edit2: Don't worry, I SOLVED IT!
I restored the 2 partitions that I overwrote with the original content, like this,
dd if=/dev/bml0/8 of=/dev/bml0/10
dd if=/dev/bml0/9 of=/dev/bml0/11
I had to be very fast, to finish it before the timeout occurred. Imagine if only half of a partition would be written...

Thanks anyway for support.

[edelfalke]

Easier (and faster) way is to change partitions back by /mtd_rwarea/PartitionSwitch_X_X.

[erdem_ua]

What I've done:

- decrypted the 2006.0 firmware
- got version_info.txt with content "SWU_T-CHLCIPDEUC_002006_I02_ES000DS000_091112" and renamed it to Version.1 (already got Version.0 on /mtd_rwarea)
- copied the 2 images and Version.1 file over to USB stick
- put stick into TV and bml.restore'd the 2 images to partitions 10 and 11 (8 and 9 where the ones already used)
- entered the Menu->Upgrade, reverted to 2006.0
- the TV restarted and ... it keeps shutting down after this...

I have access to the SSH less than 1 minute (after manually starting SamyGo extensions).
How do I switch partitions? I've tried mounting 8 and 9 over the 10 and 11 (the ones used now) with no luck.

Edit: Well, now I see this procedure was available only for CI devices, and I have CI+...stupid me...
Edit2: Don't worry, I SOLVED IT!
I restored the 2 partitions that I overwrote with the original content, like this,
dd if=/dev/bml0/8 of=/dev/bml0/10
dd if=/dev/bml0/9 of=/dev/bml0/11
I had to be very fast, to finish it before the timeout occurred. Imagine if only half of a partition would be written...

Thanks anyway for support.

Once authld defeated, you can use this way to revert your firmware back to older state.
You just needed to update hashes with correct keys.
You can follow this tread
http://forum.samygo.tv/viewtopic.php?f=2&t=655&start=20