HackRF H4M SD Card Preparation & Mayhem Firmware Flashing Guide

What You Need

• HackRF PortaPack H4M
• MicroSD card (16–32 GB, genuine brand recommended)
• SD card reader (for computer users)
• Windows or Linux computer (optional)
• Android phone with SD card slot (optional)
• USB cable (for firmware flashing)
• Internet connection

Step 1: Format Your SD Card to FAT32

Why FAT32? Mayhem firmware requires FAT32 for reliable operation.

For Windows Users

1. Insert the SD card into your computer’s card reader.
2. Open File Explorer, right-click the SD card drive and choose Format.
3. Set File system to FAT32, check Quick Format, click Start.
4. When done, safely eject the SD card.

For Linux Users

1. Insert the SD card and open a terminal.
2. Identify the device (e.g., /dev/sdb) with lsblk or fdisk -l.
3. Unmount any mounted partition:

   sudo umount /dev/sdX1

4. Format to FAT32:

   sudo mkfs.vfat -F 32 /dev/sdX

   (Replace /dev/sdX with your SD card device.)
5. Safely remove the SD card.

For Android Users (No Computer Needed)

1. Insert the SD card into your phone’s slot.
2. Open Settings > Storage, tap the SD card and choose Format or “Portable Storage.”
3. Install a file manager app (e.g., Files by Google).
4. Use the file manager to download and extract the Mayhem firmware ZIP (next step) directly to the SD card’s root.

Step 2: Download & Extract Mayhem Firmware

1. Go to the Mayhem GitHub Releases page.
2. Download the latest mayhem_vX.X.X_COPY_TO_SDCARD.zip.
3. Extract all files and folders to the root of your formatted SD card.
4. Safely eject or unmount the SD card.

Step 3: Insert SD Card and Boot Up

Insert the prepared SD card into your HackRF H4M and power on. The device will automatically load Mayhem from the card.

Step 4: Flash the Mayhem Firmware

Option A: On-Device Flash Utility

1. On your PortaPack, navigate to Utilities > Flash Utility.
2. Select the firmware file on the SD card and confirm.
3. Wait for “Flash Complete,” then reboot.

Option B: Flash via Web Tool

1. Connect your HackRF H4M to your computer via USB.
2. Open hackrf.app in your browser.
3. Click Connect Device, select the Mayhem firmware file, and click Flash.
4. After completion, disconnect and reboot your device.
5. If it doesn’t boot, repeat in DFU mode (hold the designated button while powering on).

Step 5: Verify Firmware Installation

• After reboot, the Mayhem main menu should appear.
• If not, re-check SD card format and file placement, then re-flash.
• Try another SD card or USB cable if problems persist.

Troubleshooting & Tips

• Use genuine SD cards (16–32 GB) from reputable brands.
• Always safely eject or unmount your SD card after operations.
• If flashing fails, power cycle and retry in DFU mode.
• Keep your firmware and tools up to date for best compatibility.
• On Android, ensure your file manager can extract ZIPs and write to external storage.

You can get the HackRF PortaPack H4M bundle below to start your Mayhem firmware journey with the right hardware.