efm8¶
Flash via AN945: EFM8 Factory Bootloader HID.
Usage¶
Communication is over USB-HID. This is implemented via the hidapi pthon wrapper for the hidapi native library.
On linux you can use udev to grant access:
echo 'SUBSYSTEM=="usb", ATTRS{idVendor}=="10c4", MODE="0666"' | sudo tee /etc/udev/rules.d/70-silabs.rules
udevadm trigger
efm8 firmware.hex
Also includes an example that resets a https://u2fzero.com/ into the bootloader and flashes in one command.
u2fzero firmware.hex
And a way to (slowly) read the firmware back
efm8_read firmware.hex
Installation¶
sudo apt install libusb-1.0-0-dev libudev-dev
python3 -m pip install efm8
efm8¶
Flash via AN945: EFM8 Factory Bootloader HID.
usage: efm8 [-h] [-p PRODUCT] [-s SERIAL] firmware
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firmware¶ Intel Hex format file to flash
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-h,--help¶ show this help message and exit
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-p<product>,--product<product>¶ USB Product ID of device to program
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-s<serial>,--serial<serial>¶ Serial number of device to program
The protocol is documented in AN945.
Flash via AN945: EFM8 Factory Bootloader HID.
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exception
efm8.BadChecksum¶ Checksum mismatch.
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exception
efm8.BadResponse¶ Command not confirmed.
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exception
efm8.Unsupported¶ Input file not understood.
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efm8.crc(data)¶ CITT-16, XModem.
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efm8.create_frame(cmd, data)¶ Bootloader frames start with ‘$’, 1 byte length, 1 byte command, x bytes data.
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efm8.flash(manufacturer, product, serial, frames)¶ Send bootloader frames over HID, and check confirmations.
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efm8.read_flash(manufacturer, product, serial, length)¶ Exploit CRC to read back firmware.
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efm8.read_intel_hex(filename)¶ Read simple Intel format Hex files into byte array.
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efm8.to_frames(data, checksum=True, run=True)¶ Convert firmware byte array into sequence of bootloader frames.
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efm8.toaddr(addr)¶ Split a 16bit address into two bytes (dosn’t check it is a 16bit address ;-).
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efm8.tostr(buf)¶ Ensure we have str across python versions.
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efm8.twos_complement(input_value, num_bits=8)¶ Calculate unsigned int which binary matches the two’s complement of the input.
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efm8.write_hex(buf, filename)¶ Write an Intel Format Hex file.
efm8_read¶
Flash via AN945: EFM8 Factory Bootloader HID.
usage: efm8_read [-h] [-p PRODUCT] [-s SERIAL] [-l LENGTH] firmware
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firmware¶ Intel Hex format file to flash
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-h,--help¶ show this help message and exit
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-p<product>,--product<product>¶ USB Product ID of device to program
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-s<serial>,--serial<serial>¶ Serial number of device to program
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-l<length>,--length<length>¶ Length to read
u2fzero¶
Extra utils for U2F-Zero devices.
usage: u2fzero [-h] [-p PRODUCT] [-s SERIAL] firmware
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firmware¶ Intel Hex format file to flash
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-h,--help¶ show this help message and exit
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-p<product>,--product<product>¶ USB Product ID of device to program
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-s<serial>,--serial<serial>¶ Serial number of device to program
Extra utils for U2F-Zero devices.
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efm8.u2fzero.main()¶ Command line.
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efm8.u2fzero.reset(manufacturer, product, serial)¶ Send zeroU2F jump to bootloader, trigger the host to see the device change.