I created a simple hello project with Freedom Studio, in the debug configuration I selected HiFive Unleashed board and checked the box “Create a debug lunch”. I was able to built the project when I go to lunch it I receive the following error.
Open On-Chip Debugger 0.10.0+dev (SiFive OpenOCD 0.10.0-2019.08.2)
Licensed under GNU GPL v2
For bug reports: Issues · sifive/freedom-tools · GitHub
debug_level: 0
adapter speed: 10000 kHz
Error: libusb_open() failed with LIBUSB_ERROR_NOT_FOUND
Error: no device found
Error: unable to open ftdi device with vid 0403, pid 6010, description ‘Dual RS232-HS’, serial ‘’ at bus location '’
OpenOCD could not connect to the probe. Please check:
That the probe is connected. (it appears to be disconnected)
This is the connection status
There is some trivial step which I am missing, don’t know how to debug it. (assuming my board is working fine)
I have serial connected to my computer via USB, I am able to see serial prints on my console.
OS: Windows 10
I found out the fixed the problem. Posting the solution as it may be helpful for others. (For Windows only)
The problem was default driver used for DUAL RS323-HS(openOCD) by windows was winUSB (which is also used for displaying serial output etc.) OpenOCD requires libusbK driver. There is free utility zadig.exe which allows you to swap drivers, what I did was to swap the winUSB driver of HiFive Unleashed board with libusbK, and I was able to debug the code using freedom studio.
Now when you plug in usb port into your PC supports, two interfaces will shown (one for serial, and one for Jtag) For the serial interface WinUSB driver will work and it shouldn’t be changed to libusbK, and the swap should only be done for the interface used by Jtag. (I don’t remember exactly but in my case interface 0 for serial, and interface 1 was for Jtag)
For Linux based system you can also visit the Freedom Studio User Manualpage no 165 and topic Enable Access to USB Devices. you will find complete guide here.
Make sure below prerequisites are installed
$ sudo apt-get install libusb-1.0-0 libftdi-dev libhidapi-dev libftdi1-2 libusb-0.1-4 libusb-1.0
need to properly configure permissions so we don’t have to run as root, add yourself to plugdev and dialout groups.
Now connect the HiFive unleashed to the host and verify the interface as follows
$ lsusb | grep FT2232
Bus 001 Device 010: ID 0403:6010 Future Technology Devices International, Ltd FT2232C Dual USB-UART/FIFO IC
