Conclusion and Scope

This device is a Kindle Paperwhite 1 (PW1, 2012), ultimately running Kindle 5.6.1.1 (268989 035). The following results were verified on the actual device:

• Legacy K5 Jailbreak can be installed on official firmware 5.4.4;
• After upgrading to official 5.6.1.1, BRIDGE+ appears during startup, showing that the jailbreak bridge survived;
• After installing Universal Hotfix and running Run Hotfix, KUAL's "not signed by an authorized developer" error disappears;
• KUAL launches, and KOReader can be launched from KUAL.

This handbook applies only to PW1 + 5.6.1.1. Do not use its .bin update packages on any other model, even if the names look similar.

Recommended Recovery Order

Back up USB storage
  → Downgrade to 5.4.4
  → Legacy K5 Jailbreak
  → Upgrade back to official 5.6.1.1 (look for BRIDGE+)
  → Universal Hotfix + Run Hotfix
  → Install KUAL KDK and KOReader
  → Launch KOReader from KUAL

This is the sequence that ultimately worked on this device. If KUAL shows a signature error at the 5.4.4 stage, do not keep reinstalling or flashing other packages; follow the "upgrade to 5.6.1.1 → Hotfix" repair path.

0. Ground Rules (Mandatory)

1. Keep Airplane Mode on at all times. This prevents Amazon's automatic OTA updates from overwriting the jailbreak.
2. Only one .bin file for "Update Your Kindle" can be in the Kindle's root directory at a time. Check from your computer before updating, and move all other .bin files out.
3. Always eject safely after copying. Never unplug the cable or press the power button while the Kindle is updating, restarting, or showing a progress bar.
4. Use only files from the sources listed below that match this model. Do not use packages for PW2, PW3, or newer Paperwhites.
5. Calculate the SHA-256 of every critical file once on your computer and once on the Kindle; the two must match.
6. If the update screen hangs, an unexpected error appears, or "Update Your Kindle" is unavailable, do not keep retrying. Take a photo, unplug the cable, stop in the current state, and troubleshoot.
7. Keep the battery at 50% or higher and use a reliable USB cable. A forced restart (holding power for about 40 seconds) is only for a truly unresponsive device, not a normal installation step.

1. Identify the Device and Back It Up

After connecting USB, confirm that the Kindle mounts as a disk. On macOS, it is usually /Volumes/Kindle.

Read the version file:

sed -n '1,5p' /Volumes/Kindle/system/version.txt

This device should show:

Kindle 5.6.1.1 (268989 035)

First, fully back up the Kindle's user-visible USB storage, including at least:

• documents/ (books and KUAL files)
• extensions/ (KOReader extension)
• koreader/ (KOReader program and settings)
• system/ (only as a record of the current state; do not manually copy it back)

Two local backups were made for this process:

• device-backups/pw1-pre-jailbreak-20260823
• device-backups/pw1-pre-5.6.1.1-20260823

When restoring books and KOReader settings, restore only user directories from the backup. Do not overwrite the Kindle with the entire old system/ directory.

2. Verified Critical Files

The table records the files actually used and verified in this process. If you download them again later and upstream has released a new version, the hashes may change. Stop at that point, confirm the source and release notes, and do not proceed based on the filename alone.

Verification commands:

shasum -a 256 filename
shasum -a 256 /Volumes/Kindle/filename

The first 4 bytes of a .bin file should be SP01, but that only shows it uses the Kindle update-package format; it does not replace model and hash verification:

xxd -l 16 filename.bin

3. Complete Rebuild Process

3.1 Downgrade to Official 5.4.4

Purpose: The verified entry point for Legacy K5 Jailbreak is 5.4.4.

1. Keep Airplane Mode on and complete the backup in Section 1.

2. Download and verify update_kindle_5.4.4.bin.

3. Confirm that there are no other .bin files in the Kindle's root directory:

   find /Volumes/Kindle -maxdepth 1 -type f -name '*.bin' -print

4. Copy the file directly to the Kindle's root directory. Do not put it in documents or a subfolder.

5. Recalculate the file's SHA-256 on the Kindle, and eject safely when it matches.

6. On the Kindle: Settings → Menu → Update Your Kindle.

7. Wait for it to restart automatically. After reconnecting, confirm in system/version.txt:

   Kindle 5.4.4 (225838 026)

If the version did not change, first confirm that the update package is still in the root directory, is complete, and that the update was actually triggered from the menu. Do not try to recover with unknown "force flash" tools or packages for other models.

3.2 Install Legacy K5 Jailbreak on 5.4.4

1. Download and verify kindle-5.4-jailbreak.zip.

2. After extracting it, copy the archive's contents directly to the Kindle's root directory. These 7 entries must be present:

   Update_jb_$(cd mnt && cd us && sh jb.sh).bin
   bridge.conf
   bridge.sh
   developer.keystore
   gandalf
   jb.sh
   json_simple-1.1.jar

   Important

   The filename Update_jb_$(cd mnt && cd us && sh jb.sh).bin contains $(). It is a normal filename: do not rename it, do not let a shell expand it, and do not place it inside an extra directory.

3. macOS may create ._ files when copying to a FAT-formatted Kindle. Delete those AppleDouble companion files before continuing, but do not delete the 7 real files.

4. Confirm again that this jailbreak .bin is the only one in the root directory, then eject safely.

5. On the Kindle: Settings → Menu → Update Your Kindle. The installation screen will show **** JAILBREAK ****.

6. Wait for the automatic restart, reconnect, and verify that the USB root has been cleaned up. This means the jailbreak installation stage finished normally.

3.3 Immediately Upgrade Back to Official 5.6.1.1 While Keeping the Jailbreak Bridge

This is the key step for fixing compatibility between PW1 and the newer KUAL developer signature. It is not an optional "normal upgrade."

1. After the 5.4.4 jailbreak is complete, back up USB storage again.
2. Download and verify the official update_kindle_5.6.1.1.bin. For this process, the file must be 217,523,739 bytes, with the hash shown in Section 2.
3. Leave only this official upgrade .bin in the Kindle's root directory, and verify its hash again on the Kindle.
4. After ejecting safely, go to Settings → Menu → Update Your Kindle.
5. Wait for the update and restart. Seeing BRIDGE+ during startup is the success signal needed here: the system upgraded successfully, and the jailbreak bridge survived the upgrade.
6. Reconnect USB and confirm the version is Kindle 5.6.1.1 (268989 035).

3.4 Install Universal Hotfix and Run Hotfix

Purpose: Restore/install the post-update hotfix and developer certificates on 5.6.1.1 so the system authorizes KUAL.

1. Download Update_hotfix_universal.bin from the official releases and check its version, size, and hash. The hash used here is in Section 2.
2. Put only this .bin in the Kindle's root directory. Copy it completely, recalculate its SHA-256 on the device, and eject safely.
3. On the Kindle: Settings → Menu → Update Your Kindle.
4. Wait for it to finish and restart.
5. Run Hotfix will appear in the library. Open it and let it finish. Do not restart while it is running.

After this step, KUAL, which previously said "This content is not signed by an authorized developer; please contact the developer," should open normally.

3.5 Install KUAL and KOReader

Install these after the Hotfix finishes. If the files already existed, the official upgrade usually keeps them, but you should still check the directories again.

KUAL

Place KUAL-KDK-2.0.azw2 directly in:

/Volumes/Kindle/documents/KUAL-KDK-2.0.azw2

Do not use the PEKI KUAL.jar / KUAL.sh tried earlier; on this PW1 with 5.4.4, it did not provide a usable launch path.

KOReader

Download the Kindle KOReader ZIP, extract it, and merge its root contents into the Kindle's root directory. Both of these must exist:

/Volumes/Kindle/extensions/koreader/
/Volumes/Kindle/koreader/

Do not nest the outer extracted ZIP folder; for example, do not create koreader-kindle-v.../koreader/. After copying, compare the directories to make sure all files are present. The full program was about 85 MB in this process.

Eject safely, unplug, and wait for the Kindle to index. When you open Kindle Launcher, the launch menu shows:

1. KUAL
2. KOReader
3. Quit

For the first check, choose KUAL and confirm it opens; then select KOReader from KUAL. For everyday reading, you can launch KOReader directly from the menu.

4. What Went Wrong and the Correct Fix

Symptom

After jailbreaking on 5.4.4, opening KUAL directly showed:

This content is not signed by an authorized developer. Please contact the developer.

This does not mean the KOReader files are damaged, nor does it necessarily mean the Legacy Jailbreak failed. PW1 has a compatibility issue between older firmware and current KUAL developer certificates.

Verified Fix

Keep the jailbreak completed on 5.4.4
→ Upgrade officially to 5.6.1.1 (BRIDGE+ appears at startup)
→ Universal Hotfix
→ Open Run Hotfix
→ KUAL launches normally

This process matches records from other PW1 users with the same problem and fix: MobileRead thread on the PW1 error and post-upgrade fix, and a record of PW1 using 5.6.1.1 with BRIDGE+.

5. Everyday Use and Transferring Books

• Copy legally obtained books to documents/ over USB; the native Kindle reader recognizes compatible formats.
• KOReader commonly handles EPUB, PDF, DJVU, CBZ, and more. Put files under documents/ to open them in KOReader's file browser.
• Eject safely after copying books and let the Kindle finish indexing. The first scan of a large library, or KOReader's first cache build, may take a few minutes.
• To manage or convert your own ebooks, use Calibre on your computer to convert and organize them, then transfer them over USB.

6. Troubleshooting Table

7. Boundaries for Recovery and Reset

• "Reinstalling KOReader/KUAL" usually requires only Sections 3.4 and 3.5; you do not need to downgrade and jailbreak again.
• If an official update overwrites the system, BRIDGE+ no longer appears, or you perform a factory reset, start the full process again from Section 1.
• Books and KOReader settings can be restored from the USB backup; do not write back the entire system directory.
• Before starting over, keep copies of the current /documents, /extensions, and /koreader directories so you do not lose reading progress or custom settings.

8. Completion Status (2026-08-23)

• Confirmed the device is a PW1.
• Completed Legacy K5 Jailbreak on 5.4.4.
• Upgraded to official 5.6.1.1; BRIDGE+ appears at startup.
• Installed Universal Hotfix and ran Run Hotfix.
• KUAL launches again.
• KOReader is installed and can be launched from Kindle Launcher / KUAL.
• Keep Airplane Mode on. If you need internet access later, first research and deploy an OTA-blocking method suitable for PW1.