Linux 5.19 Adding Support For The PolarBerry RISC-V FPGA Board

A few days ago the RISC-V pull request landed in Linux 5.19 with support for RISC-V 32-bit (RV32) binaries on RV64, enabling the new Svpbmt extension, and other improvements. On Friday a secondary set of RISC-V changes were sent in for Linux 5.19 that includes adding the DeviceTree files for another new RISC-V board.

Microchip Technology has contributed the DeviceTree support for the PolarBerry board that includes the PolarFire SoC FPGA for FPGA capabilities paired with a 64-bit RISC-V multi-core processor. The mainline Linux kernel has already seen PolarFire SoC support while now the PolarBerry is the latest supported board based on it.

The PolarBerry is self described as, "PolarBerry is the first production and deployment-ready SoM with a hardened 64 bit, multicore real-time, Linux-capable RISC-V MPU subsystem to deliver an unparalleled combination of defense-grade security, low power consumption, and thermal efficiency for embedded systems development...PolarBerry’s compute engine delivers up to 50% lower power than alternative FPGAs, 250k logic elements (LEs), and features four high-speed, low-power transceivers from 250Mbps to 12.7Gbps. The PolarFire SoC FPGA’s power consumption is 12W maximum and power is provided directly from the PolarBerry SoM to enable embedded solutions. The PolarBerry SoM offers all the important attributes for strong SoC/FPGA design security including anti-cloning protection, device-level anti-tamper features, bitstream protection, key management, FPGA hardware access control, secure boot and physical memory protection (PMP) as well as supply chain assurance. It also features a 40 pin Raspberry Pi (RPI) interface to allow standalone operation and rapid application development by providing up to 26 GPIOs, 20 of which can be assigned to SPI, UART, CAN, or other interfaces."

Sundance DSP PolarBerry

The Sundance PolarBerry System-on-Module has 4GB of memory, 128MB SPI serial NOR flash, 4GB eMMC for general use, Gigabit Ethernet support, and measures in at 55 x 85 mm and has a peak power draw of 16 Watts.

The PolarBerry DT is added via this secondary pull. In addition to the Sundance Digital Signal Processing Inc PolarBerry support, the memfd_secret system call number is now properly exposed to user-space and various other low-level RISC-V improvements were sent in ahead of the Linux 5.19 merge window closing this weekend.