The FU540-C000 is the world’s first 4+1 64-bit RISC‑V SoC, capable of supporting full-featured operating systems, such as Linux. It is the basis for the HiFive Unleashed Development Platform for the Freedom U500 family.
Having open source software running on new architecture(like RISC-V, SIFIVE) along with associated hardware platforms(SIFIVE-FU540, HiFive Unleashed) is always a myth. It requires a lot of effort within the organization but also from the community. The relevant Open Source software stacks Includes Firmware (OpenSBI), U-Boot (Bootloader) and Linux Kernel(OS). Here Amarula Solutions(India) voluntarily supported U-Boot mainline efforts for creating “Stanazzed boot flow for RISC-V target with help from other developers from the community.
Short summary how these Open Source software components are running on SiFive HiFive Unleashed A00 is,
- Booting of OpenSBI as fw_dynamic
- Booting of U-Boot SPL from MMC
- Booting of U-Boot SPL from SPI
- Booting of Mainline Linux using distroboot
- Booting of Mainline Linux as initramfs from SPI flash
- Booting of Mainline Linux via Mainline Buildroot
Here are the more references for Running Mainline software on SiFive HiFive Unleashed A00,
RISC-V Boot flow https://crvf2019.github.io/pdf/43.pdf