Downgrade from 5.18.1 fails with Error 12 (u-boot version mismatch)

[reckon]

Hello everyone,

I'm trying to downgrade my Kindle PaperWhite 2024 from firmware version 5.18.1 to 5.17.1.0.4.

I initially followed a guide which suggested modifying the /etc/version.txt file on the device. However, after doing that, the update process still failed with "Update Error: 12".

I checked the logs in /var/local/system/update_logs and found the specific reason for the failure. Here are the key lines from the log:

<12>[   24.186821] INFO:u-boot: 2 -> 1
<12>[   24.186827] INFO:u-boot version downgrade
<12>[   24.186834] ERROR:unbundle_file: aborting install process because of check_metadata failure.
<12>[   24.187004] ERROR:Could not unbundle /mnt-us/update_kindle_all_new_paperwhite_12th_5.17.1.0.4.bin,error_code=12

To confirm this, I used KindleTool to extract both firmware packages and compared their metadata.txt files. I can see the bootloader versions are indeed different, which explains the log.

Current Firmware (5.18.1) metadata:

bootloader_version.kernel=1
bootloader_version.quickboot=1
bootloader_version.lk=2
bootloader_version.tee=2
bootloader_version.u-boot=2

Target Firmware (5.17.1.0.4) metadata:

bootloader_version.lk=1
bootloader_version.tee=1
bootloader_version.u-boot=1

It seems clear that a bootloader anti-downgrade check is stopping the process.

My question is: What is the recommended way to proceed with the downgrade from here? I've read that a possible solution is to unpack the target firmware (5.17.1.0.4.bin), modify its internal metadata.txt to match the current bootloader versions (e.g., set u-boot to 2), and then repack it. Is this a safe and viable approach for my situation?

Any guidance or confirmation would be greatly appreciated. Thank you!

P.S. As I am not a native English speaker, this post was composed with the assistance of an AI tool to ensure clarity. Please excuse any potential awkward phrasing.

[PiperKev]

You won't be able to downgrade until your kindle is jailbroken, and there's currently no jailbreak available for 5.18.1. It's in the works, but it's not ready yet.

[j.p.s]

Originally Posted by PiperKev

You won't be able to downgrade until your kindle is jailbroken, and there's currently no jailbreak available for 5.18.1. It's in the works, but it's not ready yet.

If it is possible to access /etc and /var the kindle is already jailbroken.

[Marek]

Originally Posted by reckon

Hello everyone,

I'm trying to downgrade my Kindle PaperWhite 2024 from firmware version 5.18.1 to 5.17.1.0.4.

I initially followed a guide which suggested modifying the /etc/version.txt file on the device. However, after doing that, the update process still failed with "Update Error: 12".

I checked the logs in /var/local/system/update_logs and found the specific reason for the failure. Here are the key lines from the log:

<12>[   24.186821] INFO:u-boot: 2 -> 1
<12>[   24.186827] INFO:u-boot version downgrade
<12>[   24.186834] ERROR:unbundle_file: aborting install process because of check_metadata failure.
<12>[   24.187004] ERROR:Could not unbundle /mnt-us/update_kindle_all_new_paperwhite_12th_5.17.1.0.4.bin,error_code=12

To confirm this, I used KindleTool to extract both firmware packages and compared their metadata.txt files. I can see the bootloader versions are indeed different, which explains the log.

Current Firmware (5.18.1) metadata:

bootloader_version.kernel=1
bootloader_version.quickboot=1
bootloader_version.lk=2
bootloader_version.tee=2
bootloader_version.u-boot=2

Target Firmware (5.17.1.0.4) metadata:

bootloader_version.lk=1
bootloader_version.tee=1
bootloader_version.u-boot=1

It seems clear that a bootloader anti-downgrade check is stopping the process.

My question is: What is the recommended way to proceed with the downgrade from here? I've read that a possible solution is to unpack the target firmware (5.17.1.0.4.bin), modify its internal metadata.txt to match the current bootloader versions (e.g., set u-boot to 2), and then repack it. Is this a safe and viable approach for my situation?

Any guidance or confirmation would be greatly appreciated. Thank you!

P.S. As I am not a native English speaker, this post was composed with the assistance of an AI tool to ensure clarity. Please excuse any potential awkward phrasing.

Huh, this is new, unfortunately I don't see any way to downgrade if they are checking uboot versions now inside the kernel updater (changing the metadata and repacking is not possible since we don't have amazons Ota signing keys) only way would be dd'ing over the rootfs in user space, which doesn't sound safe or fun

[reckon]

Originally Posted by Marek

Huh, this is new, unfortunately I don't see any way to downgrade if they are checking uboot versions now inside the kernel updater (changing the metadata and repacking is not possible since we don't have amazons Ota signing keys) only way would be dd'ing over the rootfs in user space, which doesn't sound safe or fun

Thank you for the quick and clear response, Marek.

I agree, using the dd command to overwrite the root filesystem sounds extremely risky, and it's not something I'm comfortable attempting. It's a shame that a direct downgrade seems to be off the table now.

The main reason I wanted to downgrade was to fix several UI issues that were introduced with the recent update. Since downgrading isn't a viable option, perhaps I could get some help addressing these specific problems instead?

The two main issues are:

1. Inconsistent font in the page number display: In the bottom-left corner, the fonts for the numbers and the Chinese characters are not unified (e.g., in "第 1 页"). This seems to be a problem specific to the Simplified Chinese language setting.

2. A change in the highlight style: Previously, highlights on separate lines had a small vertical gap between them. Now, a highlight that spans multiple lines is rendered as a single, solid block, which I find less visually appealing.

My question is: Does anyone know where these UI styles might be defined in the Kindle's filesystem? Are they controlled by CSS files, configuration files, or something else that could potentially be modified?

What's particularly interesting is that some of these changes, especially the highlight style, did not appear immediately after the firmware update. The change happened after my device was connected to the internet for a while. I have also seen many similar reports on Chinese social media, which makes me suspect this could be a setting pushed by Amazon's servers after the initial update.

Any insight into these specific UI elements would be greatly appreciated. Thanks again for your help!

[shamanNS]

The change happened after my device was connected to the internet for a while.

Then that's probably controlled by something stored inside "experiments" table in `/var/local/KWISClient.db` database?

[Frogm4n]

Originally Posted by reckon

What's particularly interesting is that some of these changes, especially the highlight style, did not appear immediately after the firmware update. The change happened after my device was connected to the internet for a while. I have also seen many similar reports on Chinese social media, which makes me suspect this could be a setting pushed by Amazon's servers after the initial update.

Any insight into these specific UI elements would be greatly appreciated. Thanks again for your help!

It didn't take long for mine to do so after the update, but it did have a post-install update to the font system that required a reboot. It was certainly a different update kind than the usual firmware updater.

[Ebookus]

I second the hate for the new highlighting style. sucks big time