nuclei-sdk

Nuclei Software Development Kit

[!NOTE] If you want to build and run on Nuclei 100 series CPU, please read n100 support status first.

Since 0.5.0 release, Nuclei Studio >= 2023.10 and Nuclei RISC-V Toolchain/Qemu/OpenOCD >= 2023.10 are required to build and run.

Nuclei Software Development Kit(Nuclei SDK) is developed for developing and evaluating software for Nuclei Evaluation SoC.

This Nuclei SDK is built based on the NMSIS framework, user can access all the APIs provided by NMSIS and also the APIs that provided by Nuclei SDK which mainly for on-board peripherals access such as GPIO, UART, SPI and I2C etc.

This Nuclei SDK can support various compiler such as Nuclei RISC-V GCC/Clang, IAR compiler and Terapines ZCC.

We also integrated many RTOSes into Nuclei SDK, which are FreeRTOS, UCOSII, RTThread and ThreadX, you can easily find it in the OS folder.

Quick Startup

Wanner to take a try with Nuclei SDK for Nuclei 200/300/600/900/1000 series CPU, click Quick Start with Nuclei SDK to start up.

If you want to check how to use with IAR compiler, please check ideprojects/iar/README.md.

Requirements

• Ubuntu Linux >=20.04 LTS or Windows >=10
  • Linux: GNU Make >= 3.82
  • Windows: Windows Build Tools
• Nuclei Studio >= 2025.10
  • Nuclei Studio can support import Nuclei SDK NPK package to provide IDE project wizard create/build/debug.
  • Nuclei Studio also contains same release of Nuclei Toolchain/QEMU/OpenOCD, so just download IDE is enough.

Directory Structure

Here is the directory structure for this Nuclei SDK.

$NUCLEI_SDK_ROOT
├── application
│   ├── baremetal
│   ├── freertos
│   ├── ucosii
│   ├── threadx
│   └── rtthread
├── Build
│   ├── gmsl
│   ├── toolchain
│   ├── Makefile.base
│   ├── Makefile.conf
│   ├── Makefile.core
│   ├── Makefile.components
│   ├── Makefile.files
│   ├── Makefile.global
│   ├── Makefile.misc
│   ├── Makefile.rtos
│   ├── Makefile.rules
│   └── Makefile.soc
├── doc
│   ├── build
│   ├── source
│   ├── Makefile
│   └── requirements.txt
├── NMSIS
│   ├── Core
│   ├── DSP
│   ├── NN
│   └── Library
├── OS
│   ├── FreeRTOS
│   ├── UCOSII
│   ├── ThreadX
│   └── RTThread
├── SoC
│   ├── gd32vf103
│   └── evalsoc
├── test
│   ├── core
│   ├── ctest.h
│   ├── LICENSE
│   └── README.md
├── LICENSE
├── Makefile
├── NMSIS_VERSION
├── package.json
├── SConscript
├── README.md
├── setup.bat
└── setup.sh

• application

This directory contains all the application softwares for this Nuclei SDK.

The application code can be divided into mainly 4 parts, which are:

• Baremetal applications, which will provide baremetal applications without any OS usage, these applications will be placed in application/baremetal/ folder.
• FreeRTOS applications, which will provide FreeRTOS applications using FreeRTOS RTOS, placed in application/freertos/ folder.
• UCOSII applications, which will provide UCOSII applications using UCOSII RTOS, placed in application/ucosii/ folder.
• RTThread applications, which will provide RT-Thread applications using RT-Thread RTOS, placed in application/rtthread/ folder.

• ThreadX applications, which will provide ThreadX applications using ThreadX RTOS, placed in application/threadx/ folder.

• SoC

This directory contains all the supported SoCs for this Nuclei SDK, the directory name for SoC and its boards should always in lower case.

Here we mainly support Nuclei processor cores running on Nuclei FPGA evaluation boards, the support package placed in SoC/evalsoc/.

In each SoC's include directory, nuclei_sdk_soc.h must be provided, and include the soc header file, for example, SoC/evalsoc/Common/Include/nuclei_sdk_soc.h.

In each SoC Board's include directory, nuclei_sdk_hal.h must be provided, and include the board header file, for example, SoC/evalsoc/Board/nuclei_fpga_eval/Include/nuclei_sdk_hal.h.

• Build

This directory contains the key part of the build system based on Makefile for Nuclei SDK.

• NMSIS

This directory contains the NMSIS header files, which is widely used in this Nuclei SDK, you can check the NMSIS_VERSION file to know the current NMSIS version used in Nuclei-SDK.

We will also sync the changes in NMSIS project when it provided a new release.

• OS

This directory provided RTOS packages we suppported.

• LICENSE

Nuclei SDK license file.

• NMSIS_VERSION

NMSIS Version file. It will show current NMSIS version used in Nuclei SDK.

• package.json

PlatformIO package json file for Nuclei SDK, used in Nuclei Platform for PlatformIO

• SConscript

RT-Thread package scons build script, used in RT-Thread package development.

• Makefile

An external Makefile just for build, run, debug application without cd to any corresponding application directory, such as application/baremetal/helloworld/.

• setup.sh

Nuclei SDK environment setup script for Linux. You need to create your own setup_config.sh.

  # This can be path to Nuclei Studio's toolchain folder
  NUCLEI_TOOL_ROOT=/path/to/your_tool_root

In the $NUCLEI_TOOL_ROOT for Linux, you need to have Nuclei RISC-V toolchain and OpenOCD installed as below.

  ${NUCLEI_TOOL_ROOT}
  ├── gcc
  │   ├── bin
  │   ├── include
  │   ├── lib
  │   ├── libexec
  │   ├── riscv64-unknown-elf
  │   └── share
  └── openocd
      ├── bin
      ├── contrib
      ├── distro-info
      ├── OpenULINK
      ├── scripts
      └── share

• setup.bat

Nuclei SDK environment setup bat script for Windows. You need to create your own setup_config.bat.

  set NUCLEI_TOOL_ROOT=\path\to\your_tool_root

In the %NUCLEI_TOOL_ROOT% for Windows, you need to have Nuclei RISC-V toolchain, necessary Windows build tools and OpenOCD installed as below.

  %NUCLEI_TOOL_ROOT%
  ├── build-tools
  │   ├── bin
  │   ├── gnu-mcu-eclipse
  │   └── licenses
  ├── gcc
  │   ├── bin
  │   ├── include
  │   ├── lib
  │   ├── libexec
  │   ├── riscv64-unknown-elf
  │   └── share
  └── openocd
      ├── bin
      ├── contrib
      ├── distro-info
      ├── OpenULINK
      ├── scripts
      └── share

How to use

[!NOTE] To ensure compatibility when using Nuclei EvalSoC(FPGA), please verify with our Application Engineer (AE) the specific CPU configuration to confirm if the EvalSoC's CPU possesses the features you intend to test. You can utilize the cpuinfo application to determine the available CPU features on your system and cross-reference this information with the Nuclei ISA specifications.

1. Create and modify your own setup config
   • For Linux, create setup_config.sh in $NUCLEI_SDK_ROOT.
   • For Windows, create setup_config.bat in %NUCLEI_SDK_ROOT%.
2. Source the environment script right in NUCLEI_SDK_ROOT
   • For Linux: source setup.sh
   • For Windows: setup.bat

3. Build and run application.

   • Note: By default, the SoC and Board is set to evalsoc and nuclei_fpga_eval, if you don't pass any SOC and BOARD variable in Make command, it will use the default SoC and Board.
   • Assume that you will run this application -> application/baremetal/helloworld/.
   • cd application/baremetal/helloworld/
   • you can run make help to show help message.
   • We provided different Nuclei Core configurations(CORE=) we supported, see Build/Makefile.core.
     • such as CORE=n300
   • We support several download modes(DOWNLOAD=) for different applications.
     • flashxip: Program will be downloaded into flash and run directly in Flash
     • flash: Program will be downloaded into flash, when running, program will be copied to ilm/ram and run in ilm/ram
     • ilm: Program will be downloaded into ilm/ram and run directly in ilm/ram, program lost when poweroff

   • For example, if you want to build your application for CORE=n300 DOWNLOAD=ilm, you can easily run this command:

     make CORE=n300 DOWNLOAD=ilm all
     

   • If you want to upload your application for CORE=n300 DOWNLOAD=ilm, you can easily run this command:

     make CORE=n300 DOWNLOAD=ilm upload
     

   • (Option 1)If you want to debug your application for CORE=n300 DOWNLOAD=ilm:

     • First open a new terminal in the same application folder and run: make CORE=n300 DOWNLOAD=ilm run_openocd
     • Then run this command make CORE=n300 DOWNLOAD=ilm run_gdb in the existing terminal, then you can debug it using gdb, if you want to load your program, you need to type load to achieve it.
     • Notice: Since version 0.2.4, you can also pass extra GDB_PORT=<portno>, to change to use new gdb port other than default 3333, for example, make CORE=n300 DOWNLOAD=ilm GDB_PORT=3344 run_openocd and make CORE=n300 DOWNLOAD=ilm GDB_PORT=3344 run_gdb

   • (Option 2)If you want to debug your application for CORE=n300 DOWNLOAD=ilm:

     make CORE=n300 DOWNLOAD=ilm debug
     

   • If you want to use UART terminal tool to view the UART message, you can choose screen or minicom in Linux, teraterm in Windows, the default UART baudrate we use is 115200.

   Knowledge book

   • Since 0.5.0 release, Nuclei SDK only support Nuclei RISC-V Toolchain >= 2023.10, and toolchain prefix changed from riscv-nuclei-elf- to riscv64-unknown-elf-.

   • If you want to learn more about Nuclei SDK documentation, please click Nuclei SDK documentation

   • If you need to build a new application, or change CORE or DOWNLOAD option, please make sure that you have clean the project by make clean

   • If you want to specify additional compiler flags, please follow this guidance in your application Makefile.

     • Pass common compiler flags to all c/asm/cpp compiler, you can use COMMON_FLAGS in Makefile, such as COMMON_FLAGS := -O3 -funroll-loops -fpeel-loops
     • Pass C compiler only flags to c compiler, you can use CFLAGS in Makefile, such as CFLAGS := -O3 -funroll-loops -fpeel-loops
     • For ASM compiler only flags, you can use ASMFLAGS, for CPP compiler only flags, you can use CXXFLAGS.

   • If you want to pass additional linker flags, you can use LDFLAGS, and if you have additional library directories, you can use LIBDIRS to specify library directories.

   • The preprovided applications and its makefile is the best startup examples about how to use Nuclei SDK.

   • Pass extra V=1 to your make command, it will show verbose compiling information, otherwise it will only show basic information. Sample output with extra V=1

     $ make V=1 all
     Current Configuration: TOOLCHAIN=nuclei_gnu RISCV_ARCH=rv32imafdc RISCV_ABI=ilp32d RISCV_TUNE=nuclei-300-series RISCV_CMODEL=medlow SOC=evalsoc BOARD=nuclei_fpga_eval CORE=n300fd ARCH_EXT= DOWNLOAD=ilm STDCLIB=newlib_nano SMP= BOOT_HARTID=0
     Assembling :  ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc.S
     riscv64-unknown-elf-gcc -x assembler-with-cpp -O2 -DBOOT_HARTID=0 -march=rv32imafdc -mabi=ilp32d -mcmodel=medlow -mtune=nuclei-300-series -g -fno-common  -ffunction-sections -fdata-sections -DDOWNLOAD_MODE=DOWNLOAD_MODE_ILM -DDOWNLOAD_MODE_STRING=\"ILM\" -DCPU_SERIES=300  -I. -I../../../NMSIS/Core/Include -I../../../SoC/evalsoc/Board/nuclei_fpga_eval/Include -I../../../SoC/evalsoc/Common/Include -Iinc -MMD -MT ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc.S.o -MF
     ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc.S.o.d -c -o ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc.S.o ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc.S
     Assembling :  ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc_s.S
     riscv64-unknown-elf-gcc -x assembler-with-cpp -O2 -DBOOT_HARTID=0 -march=rv32imafdc -mabi=ilp32d -mcmodel=medlow -mtune=nuclei-300-series -g -fno-common  -ffunction-sections -fdata-sections -DDOWNLOAD_MODE=DOWNLOAD_MODE_ILM -DDOWNLOAD_MODE_STRING=\"ILM\" -DCPU_SERIES=300  -I. -I../../../NMSIS/Core/Include -I../../../SoC/evalsoc/Board/nuclei_fpga_eval/Include -I../../../SoC/evalsoc/Common/Include -Iinc -MMD -MT ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc_s.S.o -MF
     ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc_s.S.o.d -c -o ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc_s.S.o ../../../SoC/evalsoc/Common/Source/GCC/intexc_evalsoc_s.S
     Assembling :  ../../../SoC/evalsoc/Common/Source/GCC/startup_evalsoc.S
     

   Contributing

   Changelog