The SiFive HiFive1 was just discontinued, making it as good a time as any to introduce this project.

ezfe310 is a stripped-down, bare-metal library for targeting the SiFive FE310 series of SoCs. It's intended primarily for educators and hobbyists seeking a simple, comprehensible embedded toolchain.

ezfe310 is in beta -- you might want to wait until any bugs in the runtime or linker script are ironed out. Currently, I think it's safe, but I might be inadvertantly overwriting the bootloader (e.g. the LEDs no longer flash upon reset).

• A small, well-documented linker script for the HiFive1 (scripts/ld/hifive1.h)
• A small, well-documented runtime for C and assembly programs (src/runtime/crt0.s)
• Nearly every register and field in the FE310 exposed to C programs as an lvalue/bitmask (include/mmio.h)
• A lightweight, legible library for basic embedded functionality (ez.h)
• Example programs (src/examples/)

0. Grab a copy of the HiFive1 Getting Started Guide and the FE310 Manual at https://www.sifive.com/boards/hifive1.
1. Install your favorite RISC-V versions of GCC, GDB, and OpenOCD, and populate the fields RISCV_AS, RISCV_GCC, RISCV_GDB, and RISCV_OPENOCD in the Makefile with the appropriate paths.
2. Run make compile to compile src/main/main.c (and the runtime).
3. Plug in your HiFive1, confirm that /dev/ttyUSB1 appears, and run make upload. Consult the Getting Started Guide if something doesn't work.
4. Use your favorite TTY utility (screen, picocom, tio, etc.) to open /dev/ttyUSB1 at a baud rate of 115200.

• Verify that the linker script, etc. won't brick anything.
• Reliable UART input.
• Interrupts.
• More features from C's standard library.
• Explore GCC features (binary literals, etc.).
• Heap allocation.
• Documentation.
• Testing.
• FE310G001/HiFive Rev B support.

ezfe310 draws heavily from the work of others in the RISC-V community. The following helped provide a foundation for the project (and are good resources in their own right):

https://wiki.osdev.org/HiFive-1_Bare_Bones

https://gitlab.com/Leonhart231/hifive1

https://github.com/sifive/freedom-e-sdk/tree/v1_0