y3ll0w/efm8load

efm8 bootloader upload tool - plain python implementation

efm8load.py

A python-only implementation of the efm8 bootloader protocol.
Check out http://fishpepper.de/2016/10/15/efm8-bootloader-flash-tool-efm8load-py/ for more info.

Status

Microcontroller Unit (MCU)	Identify	Read	Write
EFM8BB10F8G	🟢	🟢	🟢
EFM8BB52F32G	🟢	🟢	🟡

🟢 = Working, 🟡 = Not tested, 🔴 = Not working

Info

• Connect the MCU to the rs232:
  • MCU RXD to TXD
  • MCU TXD to RXD
  • MCU 3v3 to 3v3 or MCU 5v to 5v (⚠️Do not mix 5v with 3v3! Check the datasheet for V_VDD and Voltage on VDD supply pin⚠️)
  • MCU GND to GND
  • MCU C2D to GND
• Empty targets boot right into the bootloader (flash[0] = 0xFF -> bootloader)

Requirements

• python3 + pip
• USB to UART Bridge Controller (e.g. CP2102)
• CP210x USB to UART Bridge VCP Drivers
• C2D Pin must be pulled low (connected to GND) during powerup to enter the bootload mode (Review section 5.3.1 Entering Bootload Mode documents/an945-efm8-factory-bootloader-user-guide.pdf for the right Pin numbers)

Setup

# Install the necessary packages
pip install -r requirements.txt

Usage

# Identify the chip
python efm8load.py -p <COM_PORT> -i

# Dump the flash memory to file
python efm8load.py -p <COM_PORT> -r dumped_flash.hex

# ⚠️Upload/Write file to flash memory⚠️
python efm8load.py -p <COM_PORT> -w dumped_flash.hex

TODO

• Add a protection to stop users from overwriting the bootloader area
• Information about decompiling the dumped flash memory