Hifive Unleashed

by Sifive

Image of Board

We founded SiFive to bring the power of open source to the semiconductor industry. We do this not only by supporting the RISC-V specification, but also by implementing the specification and getting usable chips into the hands of developers as quickly as we can. We did exactly that just over a year ago when we introduced the open source, Arduino-compatible HiFive1 dev board based on our Freedom Everywhere line of 32-bit microcontrollers. Today, we’re proud to be doing the same thing with our Freedom Unleashed 64-bit, Linux-capable system-on-chip (SoC) platform. Meet the HiFive Unleashed, the world’s first RISC-V-based, Linux-capable development board.

Industry skeptics have previously dismissed RISC-V as an academic project, low performance, and only for microcontrollers. HiFive Unleashed, featuring the SiFive Freedom U540 SoC, ends all of that. Linux and RISC-V were meant for each other, and the HiFive Unleashed dev board brings them together for the first time.

  • Processor: SiFive Freedom U540 SoC
  • Memory: 8 GB DDR4 with ECC
  • Connectivity: Gigabit Ethernet port
  • Flash: 32 MB quad SPI flash from ISSI
  • Storage: microSD card for removable storage
  • Expansion: FMC connector for future expansion

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Adafruit Blinka Installation

We use a special library called adafruit_blinka (named after Blinka, the CircuitPython mascot) to provide the layer that translates the CircuitPython hardware API to whatever library the Linux board provides.

For example, on Raspberry Pi we use the python RPi.GPIO library. For any I2C interfacing we'll use ioctl messages to the /dev/i2c device. For SPI we'll use the spidev python library, etc. These details don't matter so much because they all happen underneath the adafruit_blinka layer.