Sipeed Longan Nano

The Sipeed Longan Nano is a development board built around a GD32VF103xx MCU. The GD32VF103xx is a GigaDevice MCU with a RISC-V core and an architecture which generally assembles a STM32 MCU.

Pinout

DFU

The GD32VF103 on the Longan Nano board, like STM32 MCUs has got a built-in system bootloader, which can be activated by holding down the Boot0 button during reset. Contrary to the STM32F103 on Blue Pill boards, this bootloader appears to support DFU.

Adding a UDEV rule to make it readable:

# make this usb device accessible for users, used in WebUSB
# change the mode so unprivileged users can access it, insecure rule, though
SUBSYSTEMS=="usb", ATTR{idVendor}=="28e9", ATTR{idProduct}=="0189", MODE:="0666"

the device is recognized by dfu-util:

lth@ncpws04:~/tmp/mylifeline$ dfu-util -l
dfu-util 0.9

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

Found DFU: [28e9:0189] ver=0100, devnum=23, cfg=1, intf=0, path="2-4.5.3", alt=0, name="@Internal Flash  /0x08000000/128*001Kg", serial="??"

It is working although it is a bit weird they decided to treat the entire flash as one block of 128 kB. According to the User Manual the flash _can_ be erased per 1 kB page.

Gallery

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Miscellaneous Links

• Bare metal RISC-V on GD32VF103CB
• Longan Nano (GD32VF103) details
• Original firmware
• GD32VF103Inator
• Getting started with the GD32VF103 RISC-V microcontroller
• [file:///tmp/GD32VF103_Firmware_Library_User_Guide_V1.0.pdf GD32VF103 Firmware Library User guide]