Nuclei 100 Series Core Device Templates

The evalsoc implementation in Nuclei N100 SDK serves as a latest reference implementation using Nuclei 100 series CPU.

We support the following toolchains in this evalsoc implementation:

Nuclei RISC-V GNU Toolchain: https://doc.nucleisys.com/nuclei_tools/toolchain/gnu/index.html
Nuclei RISC-V LLVM Toolchain: https://doc.nucleisys.com/nuclei_tools/toolchain/llvm/index.html
IAR RISC-V Toolchain: http://iar.com/riscv
Terapines ZCC Toolchain: https://www.terapines.com/products/zcc

Quick Porting Guide

To quickly port this SDK to your custom SoC (designed with Nuclei 100 series CPU), please refer to our comprehensive porting guide:

Configuration Files
- npk.yml: Board Support Package Configuration File for NPK
- openocd_evalsoc.cfg: OpenOCD configuration for on-board debugging using HummingBird Debugger
Header Files (Include/)
- nuclei_sdk_hal.h: Hardware abstraction layer interface
- Defines debug UART (UART0)
- Configures debug output or suppress debug output via NMSIS_DISABLE_DEBUG
- board_nuclei_fpga_eval.h: Board specific header file for peripheral access if needed
Linker Scripts (Source/GCC/ and Source/IAR/)
- Source/GCC: Linker Scripts for GCC/Clang toolchain
- Source/IAR: Linker Scripts for IAR toolchain
- Provide sample linker script in GCC/Clang toolchain:
- gcc_evalsoc_sram.ld: code and data all placed in sram
- Provide sample linker script in IAR toolchain:
- iar_evalsoc_sram.icf: code and data all placed in sram

evalsoc.svd: System View Description file, provided by SoC vendor
- Peripheral register definitions
- Interrupt configurations
- Memory map details
npk.yml: SoC Support Package Configuration File for NPK

cpufeature.h: Nuclei RISC-V CPU feature header file
- This file is generated by nuclei_gen tool
- Used by evalsoc.h to define CPU feature macros used in NMSIS Core header files
evalsoc.h: Core SoC definitions
- Base addresses for peripherals
- Interrupt definitions
- Nuclei RISC-V CPU feature macros
- You can customize this file to add more SoC definitions
evalsoc_uart.h: UART driver interface
system_evalsoc.h: System configuration
- Clock initialization
- Core initialization routines
- System frequency setup
- Interrupt(IRQC) and Exception API
nuclei_sdk_soc.h: SDK SoC common header file
- Includes all peripheral headers
- Common definitions for the SoC
- Include evalsoc.h

Startup/Interrupt and Exception Code
- Startup Code:
- GCC/Clang version: GCC/startup_evalsoc.S
- IAR version: IAR/startup.S and IAR/startup_evalsoc.c
- Interrupt and Exception Code:
- GCC/Clang version: M-Mode -> GCC/intexc_evalsoc.S
- IAR version: M-Mode -> IAR/intexc_evalsoc.S
System Configuration Code
- evalsoc_common.c: get soc frequency via timer freq, and delay function and etc, which can be deleted if not needed
- system_evalsoc.c: template code for system configuration, it will do premain initialization, interrupt and exception initialization, uart initialization and print banner, you can customize it as needed
Driver Implementations(Drivers)
- UART driver: evalsoc_uart.c
Standard C Library Stub Code(Stubs)
- Newlib stubs: Stubs/newlib
- IAR DLib stubs: Stubs/iardlib
- Nuclei C Runtime Library(libncrt) stubs: Stubs/libncrt
- You only need one of them depending on your which c library you are using

build.mk: Main build rules for the SoC
- CPU ARCH related compiler flags such as march, mabi and mtune
- Include paths
- Source files
- Support code if you have qemu or other simulators supported
cpufeature.mk: CPU extension configuration
- Select which CPU Core you are using, see https://doc.nucleisys.com/nuclei_n100_sdk/develop/buildsystem.html#develop-buildsystem-var-core
- Select which CPU extensions you are using, see https://doc.nucleisys.com/nuclei_n100_sdk/develop/buildsystem.html#arch-ext
- Used by build.mk