Safety & Partition Backups

Crucial Warning: Back Up Before Flashing!

Every cellular device has radio-frequency (RF) calibration values and an IMEI uniquely paired to its hardware. On Qualcomm devices, this data is stored in the Non-Volatile (NV) RAM and specific flash partitions:

• modemst1
• modemst2
• fsg
• fsc

If you erase or overwrite these partitions without having a backup, your modem will never register on a cellular network again, and the device will be restricted to Wi-Fi only.

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Method 1: Full Backup via Qualcomm EDL Mode (Recommended)

Qualcomm Emergency Download (EDL / 9008) mode operates at the primary bootloader level in ROM. It allows you to read the entire eMMC raw storage byte-for-byte, even if the operating system is locked or corrupted.

1. Requirements

• Python 3.8+ installed on your computer.
• The open-source edl tool:

  git clone https://github.com/bkerler/edl.git
  cd edl
  pip install -r requirements.txt

2. Enter EDL Mode

Connect the dongle while shorting the EDL test points (or use adb reboot edl if ADB is active). Your computer should detect:

• Linux: Qualcomm, Inc. Gobi Wireless Modem (QDL mode) in lsusb
• Windows: Qualcomm HS-USB QDLoader 9008 in Device Manager

3. Dump the Critical Calibration Partitions

Run edl to dump the radio partitions:

# Dump the primary partition table
python3 edl.py r gpt gpt_backup.bin

# Dump the modem calibration partitions
python3 edl.py r modemst1 modemst1.bin
python3 edl.py r modemst2 modemst2.bin
python3 edl.py r fsg fsg.bin
python3 edl.py r fsc fsc.bin

# (Optional but recommended) Dump the boot and recovery partitions
python3 edl.py r boot boot_stock.bin
python3 edl.py r aboot aboot_stock.bin

4. Create a Full eMMC Image (Ultimate Safety)

If you have 4–8 GB of disk space on your computer, dump the entire flash drive:

# Dump entire eMMC drive
python3 edl.py rl my_dongle_full_dump/

Store my_dongle_full_dump/ in a safe folder or cloud backup. If anything ever goes wrong, you can completely restore the device to factory state with python3 edl.py wl my_dongle_full_dump/.

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Method 2: Backup via ADB Root (If Available)

If your device’s stock Android OS allows adb root:

# Obtain root shell
adb root
adb wait-for-device

# Create a backup folder on the device
adb shell "mkdir /sdcard/backup"

# Dump calibration partitions directly from block devices
adb shell "dd if=/dev/block/bootdevice/by-name/modemst1 of=/sdcard/backup/modemst1.img"
adb shell "dd if=/dev/block/bootdevice/by-name/modemst2 of=/sdcard/backup/modemst2.img"
adb shell "dd if=/dev/block/bootdevice/by-name/fsg of=/sdcard/backup/fsg.img"
adb shell "dd if=/dev/block/bootdevice/by-name/fsc of=/sdcard/backup/fsc.img"

# Pull the backup to your PC
adb pull /sdcard/backup ./modem_backup/

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How to Restore Your Backup If Cellular Fails

If after flashing Linux or OpenWrt your modem shows No SIM or refuses to register on 4G LTE:

1. Put the dongle into EDL mode.
2. Restore the original calibration files:

   python3 edl.py w modemst1 modemst1.bin
   python3 edl.py w modemst2 modemst2.bin
   python3 edl.py w fsg fsg.bin
   python3 edl.py w fsc fsc.bin
   python3 edl.py reset

3. Reboot the device. Cellular functionality and original IMEI will be fully restored!