BBB screwdriver

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A util for coreboot developer. It's based on OpenWrt.

Warning: NOTE: This page is outdated. The improved page can be found here: BeagleBone Black - screwdriver

Supports ehci debug and spi flashing

Connect to the device

You can connect via a serial TTL 3.3V cable (Connector J1 - Pin1 GND, Pin4 RX, Pin5 TX)

or via network. The BBB acts as DHCP server under the IP

  • User root/coreboot
  • ssh root@

Howto use spi?

Wire the cables.

howto wire the spi chip

BeagleBoneBlack Pin on Port 9 SPI SPI Soic8 Pin CPU DTS
I2C1_SCL 17 CS 1 A16 spi0_cs0
I2C1_SDA 18 MOSI 5 B16 spi0_d1
UART2_RXD 22 CLK 6 A17 spi0_sclk
UART2_TXD 21 MISO 2 B17 spi0_d0
VDD_3V3D 3 + 4 VCC 8 VDD_3V3D VDD_3V3D
  • flashrom -p linux_spi:dev=/dev/spidev1.0

Howto use ehci debug?


  • USB mini cable
  • DC 5V plug

Connect to debug console

  1. Plug in power cable
  2. Connect usb cable to your target usb port
  3. Connect to the screwdriver via ssh or serial using on of:
  • screen /dev/ttyGS0
  • cat /dev/ttyGS0 | tee -a /tmp/output



  1. howto_wire_the_spi_chip
  2. BBB Schematics
  3. screwdriver repo
  4. OpenWrt Network Configuration
  5. CPU Datasheet
  6. am335x CPU Technical Reference