JioPhone LF-2403N — EDL / Root Toolkit

Tools and documentation to back up, root, and re-flash a JioPhone LF-2403N (Qualcomm MSM8905/8909, KaiOS 2.5, Gecko 48) from a Windows PC over Qualcomm EDL (Emergency Download / firehose), with a reproducible one-command setup.

It gets you: a full partition backup/restore workflow, authorized ADB, and a persistent root shell — the foundation for further modding. Built on that, os/ cross-compiles Sun's phoneME (CLDC-HI + MIDP 2.1) into a single static ARM binary that runs J2ME MIDlets directly on the LCD framebuffer and keypad with KaiOS stopped — a native "J2ME OS" mode.

⚠️ Disclaimer — read this. Rooting/flashing a phone can brick it and voids your warranty. This replaces the boot partition and lowers device security (SELinux permissive, root, a baked-in ADB key). Everything here is reversible (you keep a stock boot backup) and the IMEI/EFS partitions are never touched — but you do this at your own risk. The authors are not liable for any damage.

No firmware is distributed here. The JioPhone/LYF firmware and its signed loader are copyrighted by Reliance Jio / Qualcomm. You download the firmware yourself; the scripts extract only what's needed, locally. Use this only on your own device.

What it does

• Talks to the phone in EDL on Windows via a patched bkerler edl (the key fix: use the WinUSB driver + libusb-package so the Sahara HELLO isn't dropped — the thing that makes EDL actually work here).
• Uses the OEM-signed firehose loader (from stock firmware) to pass secure boot, then reads/writes any partition.
• Builds a rooted boot: ro.secure=0, SELinux permissive, your ADB public key injected as /adb_keys, and a tiny setuid-root helper /s60su for a uid=0 shell (KaiOS's adbd is hardened to stay shell, so we bring our own).

Quick start

# 1. Set up the environment (Python, edl clone + patches, deps, Zadig)
powershell -ExecutionPolicy Bypass -File tools\setup.ps1

# 2. Provide the firmware you downloaded (see "Firmware" below)
python tools\fetch_firmware.py -Zip "C:\path\LYF-LF2403N-...-QFT.zip"

# 3. Generate your local ADB key credential
powershell -File tools\prepare_adbkey.ps1

Then follow tools/HOW_TO_START.md (full setup + requirements) and tools/README.md (command reference): put the phone in EDL, back up boot, build the rooted boot, flash, and get root.

Firmware

Download the LF-2403N stock firmware (a LYF-LF2403N-…-QFT.zip, ~660–690 MB) from a firmware mirror (search "LYF LF2403N flash file"; MediaFire mirrors are more reliable than the quota-limited Google Drive ones). Then tools\fetch_firmware.py -Zip <zip> extracts the signed loader, stock boot, and partition XMLs into firmware/ (which is gitignored).

Repository layout

tools/          scripts + docs (this is the toolkit)
  setup.ps1              one-command environment setup
  fetch_firmware.py      extract loader/boot from the firmware zip
  prepare_adbkey.ps1     generate firmware/adbkey.pub from your adb key
  build_s60su.ps1        build the setuid-root helper (WSL + ARM gcc)
  apply_edl_patch.py     apply the edl source patches to a fresh clone
  patch_boot.py          dump/patch an Android boot image
  make_root_boot.py      build the rooted boot image
  s60su.c                setuid-root shell helper (source)
  edl.cmd, patch_boot.cmd, *.py   wrappers + EDL diagnostics
  README.md, HOW_TO_START.md      reference + from-scratch guide
firmware/       empty in the repo; populated locally (gitignored)
os/             native J2ME runtime: phoneME cross-built for the phone, running on
                the framebuffer with KaiOS stopped (see os/README.md)

Not included (regenerated or downloaded locally, and gitignored): the firmware zip and extracted blobs, your adbkey.pub, boot images, the compiled s60su, zadig.exe, and the tools/edl/ clone.

Credits

• bkerler/edl — the Qualcomm EDL client (GPLv3; cloned by setup.ps1, not vendored here).
• The BananaHackers community — KaiOS/JioPhone reference.

License

MIT — see LICENSE.