Possible way to downgrade your kindle on 5.8.10

[unidevel]

I have a kindle voyage which run on 5.8.10 now, I want to jailbreak it, but found the firmware update_KV_5.5.0_initial.bin always disappear when I disconnect the USB.

So next time I did not to disconnect USB, and long press the power button to let it reboot without disconnect, seems it can flash the firmware, however, it report me ERROR 16 after flash, and it let me reboot to my 5.8.10 without problem.

[knc1]

Originally Posted by unidevel

I have a kindle voyage which run on 5.8.10 now, I want to jailbreak it, but found the firmware update_KV_5.5.0_initial.bin always disappear when I disconnect the USB.

So next time I did not to disconnect USB, and long press the power button to let it reboot without disconnect, seems it can flash the firmware, however, it report me ERROR 16 after flash, and it let me reboot to my 5.8.10 without problem.

1) You are in the wrong forum - post in the Kindle Developer's Corner sub-forum of this one.

2)No, that will not work for any firmware more recent than the 5.6.1.1 build for the PW1 (but not the 5.6.1.1 build for the PW3).

[unidevel]

@knc1, I'm not sure how to remove this post to developer section or delete it, please help delete it, thanks.

[knc1]

Originally Posted by unidevel

@knc1, I'm not sure how to remove this post to developer section or delete it, please help delete it, thanks.

I can't do it myself.
But there is a moderator who comes by fairly often, he will deal with it.

It isn't a really big deal, but a visitor is more likely to get relevant help if they follow a simple rule:
If it has something to do with a Kindle while being used as Amazon intended, it belongs in this forum.
If it has something to do with a Kindle being used in a way Amazon did not intend, it belongs in the sub-forum.

I.E:
The Mobileread after-market add-ins for the Amazon Kindle come from the sub-forum and are maintained there.
Since Amazon Corporate policy is: "After-market add-ins are not supported." (and they build their firmware to enforce that policy) - -
All things jail break related are dealt with in the sub-forum.

The people in this forum only use the Kindle to read things.
Anything else is just "noise".

[unidevel]

I enable the logging, I found something interesting

70828:060038 [ 5.069795] <4>[ 6.493223] ERROR:bundle/unbundle_wario.c:1566:do_unbundle():do_unbundle: FB02 bundle could not be applied over FB03
170828:060038 [ 5.069828] <4>[ 6.493679] INFO:bundle/unbundle_wario.c:2078:unbundle():No uboot image found! skipping uboot installation.
170828:060038 [ 5.069859] <4>[ 6.493730] ERROR:update.c:262:update_os():Could not unbundle /mnt-us/update_KV_5.5.0_initial.bin,error_code=16
170828:060038 [ 5.069890] <4>[ 35.644480] /mnt-us/update_KV_5.5.0_initial.bin MD5SUM: f7c8905ea993fef902be82b70a98542a
170828:060038 [ 5.069906] <4>[ 35.644638] INFO:update.c:43:remove_file_ll():removing /mnt-us/update_KV_5.5.0_initial.bin

Seems the update_KV_5.5.0_initial.bin packaged with "recovery"(FB02) option, and seemds 5.8.10 requires "recovery2"(FB03). I wonder if the downgrade image repackaged with recovery2 option, then it may work.

[knc1]

Originally Posted by unidevel

I enable the logging, I found something interesting

70828:060038 [ 5.069795] <4>[ 6.493223] ERROR:bundle/unbundle_wario.c:1566:do_unbundle():do_unbundle: FB02 bundle could not be applied over FB03
170828:060038 [ 5.069828] <4>[ 6.493679] INFO:bundle/unbundle_wario.c:2078:unbundle():No uboot image found! skipping uboot installation.
170828:060038 [ 5.069859] <4>[ 6.493730] ERROR:update.c:262:update_os():Could not unbundle /mnt-us/update_KV_5.5.0_initial.bin,error_code=16
170828:060038 [ 5.069890] <4>[ 35.644480] /mnt-us/update_KV_5.5.0_initial.bin MD5SUM: f7c8905ea993fef902be82b70a98542a
170828:060038 [ 5.069906] <4>[ 35.644638] INFO:update.c:43:remove_file_ll():removing /mnt-us/update_KV_5.5.0_initial.bin

Seems the update_KV_5.5.0_initial.bin packaged with "recovery"(FB02) option, and seemds 5.8.10 requires "recovery2"(FB03). I wonder if the downgrade image repackaged with recovery2 option, then it may work.

Yes it would.
Can you get us a copy of Amazon's private signing key?
OR
How about reverse engineering their 2048bit RSA key pair?
Just add that to KindleTool and we are ready for anything.

We are limited to signing with OUR key pair, we don't have access to Amazon's.
(And the 'jail break' is just adding our public key to the Kindle's key store.)

= = = =

When Amazon/Lab126 blocked the use of FB02 packages, they also blocked people from installing the VoiceView voices.
The VV voices are also in an FB02 package type.
Professional C.S. developers have a name for that: "Oops".
https://www.mobileread.com/forums/sh...d.php?t=289923

So expect things to change, sometime, maybe this fall if they intend to introduce any new models. (they would probably roll in fixing their packaging problem with any other changes a new model(s) would require.)

= = = =

The most recent test results Amazon has published with the 'Top 500' list keepers had their supercomputer ranked 16th in the world.
You can get a free account on their supercomputer (see Amazon EC2).
Although they do charge if you use more than a single core at a time.
I.E: Using a million cores or so IS NOT free.
But if you want to start trying to reverse a 2048bit RSA key pair, that might be the place to start.

# 14 600

[unidevel]

Originally Posted by knc1

Yes it would.
Can you get us a copy of Amazon's private signing key?
OR
How about reverse engineering their 2048bit RSA key pair?
Just add that to KindleTool and we are ready for anything.

We are limited to signing with OUR key pair, we don't have access to Amazon's.
(And the 'jail break' is just adding our public key to the Kindle's key store.)

# 14 600

Well, I don't know how to get the private key. Besides, I also don't think the private key will be shipped with any update bundle.

Let me know how to get it, thanks

[knc1]

Originally Posted by unidevel

Well, I don't know how to get the private key. Besides, I also don't think the private key will be shipped with any update bundle.

Let me know how to get it, thanks

I was being sarcastic.

I doubt that it ever leaves the corporate office safe.
If it ever reached the factory (in China), then . . . .