This repository, maintained by SiFive Inc, makes it easy to get started developing software for the Freedom E and Freedom S Embedded RISC-V Platforms. This SDK is intended to work on any target supported by SiFive's distributions of the RISC-V GNU Toolchain.

Documentation for Freedom E SDK is available here

Freedom E SDK was recently transitioned to using the Freedom Metal compatibility library. If you're looking for the old Freedom E SDK, software examples, and board support files, you can find those on the v1_0 branch.

Freedom Metal (Documentation) is a library developed by SiFive for writing portable software for all of SiFive's RISC-V IP, RISC-V FPGA evaluation images, and development boards. Programs written against the Freedom Metal API are intended to build and run for all SiFive RISC-V targets. This makes Freedom Metal suitable for writing portable tests, bare metal application programming, and as a hardware abstraction layer for porting operating systems to RISC-V.

• Board Support Packages (found under bsp/)
  • Supported Targets:
    • SiFive HiFive 1
      • sifive-hifive1
    • SiFive HiFive 1 Rev B
      • sifive-hifive1-revb
    • SiFive Freedom E310 Arty
      • freedom-e310-arty
    • SiFive CoreIP RTL
      • coreip-e20-rtl
      • coreip-e21-rtl
      • coreip-e24-rtl
      • coreip-e31-rtl
      • coreip-e34-rtl
      • coreip-s51-rtl
      • coreip-s54-rtl
      • coreip-e76-rtl
      • coreip-s76-rtl
    • SiFive CoreIP Arty FPGA Evaluation targets
      • coreip-e20-arty
      • coreip-e21-arty
      • coreip-e24-arty
      • coreip-e31-arty
      • coreip-e34-arty
      • coreip-s51-arty
      • coreip-s54-arty
      • coreip-e76-arty
      • coreip-s76-arty
  • The board support files for the Freedom Metal library are located entirely within a single target directory in bsp/<target>/. For example, the HiFive 1 board support files for Freedom Metal are entirely within bsp/sifive-hifive1/ and consist of the following:
    • design.dts
      • The DeviceTree description of the target. This file is used to parameterize the Freedom Metal library to the target device. It is included as reference so that users of Freedom Metal are aware of what features and peripherals are available on the target.
    • metal.h
      • The Freedom Metal machine header which is used internally to Freedom Metal to instantiate structures to support the target device.
    • metal.%.lds
      • Generated linker scripts for the target. The different scripts allow for different memory configurations.
    • openocd.cfg (for development board and FPGA targets)
      • Used to configure OpenOCD for flashing and debugging the target device.
    • settings.mk
      • Used to set -march and -mabi arguments to the RISC-V GNU Toolchain.
• A Few Example Programs (found under software/)
  • hello
    • Prints "Hello, World!" to stdout, if a serial device is present on the target.
  • return-pass
    • Returns status code 0 indicating program success.
  • return-fail
    • Returns status code 1 indicating program failure.
  • example-itim
    • Demonstrates how to statically link application code into the Instruction Tightly Integrated Memory (ITIM) if an ITIM is present on the target.
  • software-interrupt
    • Demonstrates how to register a handler for and trigger a software interrupt
  • timer-interrupt
    • Demonstrates how to register a handler for and trigger a timer interrupt
  • local-interrupt
    • Demonstrates how to register a handler for and trigger a local interrupt
  • example-pmp
    • Demonstrates how to configure a Physical Memory Protection (PMP) region
  • sifive-welcome
    • Prints the SiFive banner and blinks LEDs
  • dhrystone
    • "Dhrystone" Benchmark Program by Reinhold P. Weicker

To use this SDK, you will need the following software available on your machine:

• GNU Make
• Git
• RISC-V GNU Toolchain
• RISC-V OpenOCD (for use with development board and FPGA targets)
• Segger J-LINK (for use with certain development boards)

The RISC-V GNU Toolchain and OpenOCD are available from the SiFive Website at

https://www.sifive.com/boards

For OpenOCD and/or RISC-V GNU Toolchain, download the .tar.gz for your platform, and unpack it to your desired location. Then, use the RISCV_PATH and RISCV_OPENOCD_PATH variables when using the tools:

cp openocd-<date>-<platform>.tar.gz /my/desired/location/
cp riscv64-unknown-elf-gcc-<date>-<platform>.tar.gz /my/desired/location
cd /my/desired/location
tar -xvf openocd-<date>-<platform>.tar.gz
tar -xvf riscv64-unknown-elf-gcc-<date>-<platform>.tar.gz
export RISCV_OPENOCD_PATH=/my/desired/location/openocd
export RISCV_PATH=/my/desired/location/riscv64-unknown-elf-gcc-<date>-<version>

Some targets supported by Freedom E SDK (like the SiFive HiFive1 Rev B) use Segger J-Link OB for programming and debugging. If you intend to use these targets, install the Segger J-Link Software and Documentation Pack for your machine:

Segger J-Link Software Downloads

This repository can be cloned by running the following commands:

git clone --recursive https://github.com/sifive/freedom-e-sdk.git
cd freedom-e-sdk

The --recursive option is required to clone the git submodules included in the repository. If at first you omit the --recursive option, you can achieve the same effect by updating submodules using the command:

git submodule update --init --recursive

If you'd like to update your SDK to the latest version:

git pull origin master
git submodule update --init --recursive

To compile a bare-metal RISC-V program:

make [PROGRAM=hello] [TARGET=sifive-hifive1] [CONFIGURATION=debug] software

The square brackets in the above command indicate optional parameters for the Make invocation. As you can see, the default values of these parameters tell the build script to build the hello example for the sifive-hifive1 target with the debug configuration. If, for example, you wished to build the timer-interrupt example for the S51 Arty FPGA Evaluation target, with the release configuration, you would instead run the command

make PROGRAM=timer-interrupt TARGET=coreip-s51-arty CONFIGURATION=release software

Building a benchmark program is slightly special in that certain section is required to be loaded in specific memory region. A specialize linker file has been created for its optimal run.

make PROGRAM=dhrystone TARGET=coreip-e31-arty LINK_TARGET=ramrodata software

make [PROGRAM=hello] [TARGET=sifive-hifive1] [CONFIGURATION=debug] upload

make [PROGRAM=hello] [TARGET=sifive-hifive1] [CONFIGURATION=debug] debug

make [PROGRAM=hello] [TARGET=sifive-hifive1] [CONFIGURATION=debug] clean

You can export a program to a standalone project directory using the standalone target. The resulting project will be locked to a specific TARGET. Note that this functionality is only supported for Freedom Metal programs, not the Legacy Freedom E SDK.

STANDALONE_DEST is a required argument to provide the desired project location.

make [PROGRAM=hello] [TARGET=sifive-hifive1] [INCLUDE_METAL_SOURCES=1] STANDALONE_DEST=/path/to/desired/location standalone

Run make help for more commands.

Documentation, Forums, and much more available at

dev.sifive.com