neorv32

Based on the repository https://github.com/stnolting/neorv32 and has been modified to enable cross compilation on Windows and Linux.

Additionally, some top headers, for HDL, have been translated from VHDL to Verilog under the folders:

• rtl/processor_templates
• rtl/system_integration
• rtl/test_setups in order to maximize portability across Verilog HDL users.

Windows Installation and example of cross compilation

1. Installation

You must download the latest RISCV precompiled binaries for your platform from: https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/

in this case the architecture x64 for windows binaries(https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v13.2.0-2/xpack-riscv-none-elf-gcc-13.2.0-2-darwin-x64.tar.gz), then extract these under the folder C:\riscv_precompiled\

Note: If you change the location where you installed the RISC-V precompiled binaries, you need to modify line 42 of the file common.mk. This will be explained further in this manual at point number 8.

Your precompiled binaries should look like this on your file system:

2. Cloning repository

Clone or download this repository on your windows machine.

$ git clone https://gitea.squirrelnut.synology.me:5001/FPGALover/neorv32

2. Download and install MSYS2(msys2-x86_64-20240113.exe) --> https://www.msys2.org/

Once MSYS2 is installed, run MSYS2, and run the command using the MYSS2 command shell (pacman -S mingw-w64-ucrt-x86_64-gcc)

$ pacman -S mingw-w64-ucrt-x86_64-gcc

Select ALL dependencies by pressing Enter and select Y[yes].

resolving dependencies...
looking for conflicting packages...

Packages (15) mingw-w64-ucrt-x86_64-binutils-2.41-2
            mingw-w64-ucrt-x86_64-crt-git-11.0.0.r216.gffe883434-1
            mingw-w64-ucrt-x86_64-gcc-libs-13.2.0-2  mingw-w64-ucrt-x86_64-gmp-6.3.0-2
            mingw-w64-ucrt-x86_64-headers-git-11.0.0.r216.gffe883434-1
            mingw-w64-ucrt-x86_64-isl-0.26-1  mingw-w64-ucrt-x86_64-libiconv-1.17-3
            mingw-w64-ucrt-x86_64-libwinpthread-git-11.0.0.r216.gffe883434-1
            mingw-w64-ucrt-x86_64-mpc-1.3.1-2  mingw-w64-ucrt-x86_64-mpfr-4.2.1-2
            mingw-w64-ucrt-x86_64-windows-default-manifest-6.4-4
            mingw-w64-ucrt-x86_64-winpthreads-git-11.0.0.r216.gffe883434-1
            mingw-w64-ucrt-x86_64-zlib-1.3-1  mingw-w64-ucrt-x86_64-zstd-1.5.5-1
            mingw-w64-ucrt-x86_64-gcc-13.2.0-2

Total Download Size:    49.38 MiB
Total Installed Size:  418.82 MiB

:: Proceed with installation? [Y/n]
[... downloading and installation continues ...]

After the installation is completed, add the Path "C:\msys64\ucrt64\bin" under the enviroments variable on Windows.


Open a windows cmd and run the command (gcc --version)

$ gcc --version
gcc.exe (Rev2, Built by MSYS2 project) 13.2.0

Using windows explorer, go to the folder C:\msys64\ucrt64\bin make a copy of the file mingw32-make.exe and rename it as make.exe

3. Cross-Compiling

Using the windows CMD, go to the directory where you cloned or donwloaded this repository to the directory neorv32\sw\example\demo_blink_led_asm

$ cd neorv32\sw\example\demo_blink_led_asm

Note: if you changed the location of the precompiled RISCV binaries, you need to modify the file "neorv32\sw\common\common.mk" at the line # 42:

# Compiler toolchain	
    RISCV_PREFIX =  **<your directory to where you installed the prebuilt compiler>\riscv-none-elf-**

Run the command make all (make sure all antivirus are disabled)

$ make all
"Memory utilization:"
text    data     bss     dec     hex filename
    432       0       0     432     1b0 main.elf
"Generationg APP BIN"
"OK - APP BIN"
"Generationg APP IMG VHD"
"OK - APP IMG VHD"
"Generationg RAW HEX"
"OK - RAW HEX"
"Generationg RAW BIN"
"OK - RAW BIN"
"Generationg BOOT IMG VHD"
"OK - BOOT IMG VHD"
"Memories Generated"    

List the generated files and you will see

$ ls -l
-rw-rw-rw-  1 adriz 0 6781 2024-02-24 01:45 main.asm
-rw-rw-rw-  1 adriz 0  432 2024-02-24 01:45 main.bin
-rw-rw-rw-  1 adriz 0 8708 2024-02-24 01:45 main.elf
-rw-rw-rw-  1 adriz 0 5456 2024-02-23 16:14 main.S
-rw-rw-rw-  1 adriz 0 2764 2024-02-24 01:45 main.S.o
-rw-rw-rw-  1 adriz 0  274 2024-02-24 01:16 makefile
-rw-rw-rw-  1 adriz 0 1882 2024-02-24 01:45 neorv32_application_image.vhd
-rw-rw-rw-  1 adriz 0 1878 2024-02-24 01:45 neorv32_bootloader_image.vhd
-rw-rw-rw-  1 adriz 0  444 2024-02-24 01:45 neorv32_exe.bin
-rw-rw-rw-  1 adriz 0  432 2024-02-24 01:45 neorv32_raw_exe.bin
-rw-rw-rw-  1 adriz 0  972 2024-02-24 01:45 neorv32_raw_exe.hex

You have been able to Assemble assembly code for the RISCV on windows.

Go con the folder neorv32\sw\example\demo_blink_led which is the same example as the previous one but written on C code., and run the line "make all"

$ make all
"Memory utilization:"
    text    data     bss     dec     hex filename
    1092       0       0    1092     444 main.elf
"Generationg APP BIN"
"OK - APP BIN"
"Generationg APP IMG VHD"
"OK - APP IMG VHD"
"Generationg RAW HEX"
"OK - RAW HEX"
"Generationg RAW BIN"
"OK - RAW BIN"
"Generationg BOOT IMG VHD"
"OK - BOOT IMG VHD"
"Memories Generated" 

Now you have cross-compiled sucessfuly on windows for C and Assembly code.

If you go to the folder neorv32\sw\example, and run the command "make all" you will be able to build all the projects within this folder.

Enjoy!

Linux Installation and example of cross compilation

1. Installation

Open shell and run:

sudo apt-get update
sudo apt-get install autoconf automake autotools-dev curl python3 python3-pip libmpc-dev libmpfr-dev libgmp-dev gawk build-essential bison flex texinfo gperf libtool patchutils bc zlib1g-dev libexpat-dev ninja-build git cmake libglib2.0-dev
git clone https://github.com/riscv/riscv-gnu-toolchain
cd riscv-gnu-toolchain/
mkdir build/
cd build
sudo mkdir /opt/riscv32im
sudo chown $USER /opt/riscv32im
../configure --with-arch=rv32im --prefix=/opt/riscv32im
make -j$(nproc)

2. Clone this repo

Using shell, go to the directory where you cloned or donwloaded this repository to the directory neorv32\sw\example\demo_blink_led_asm

$ git clone https://gitea.squirrelnut.synology.me:5001/FPGALover/neorv32
$ cd neorv32\sw\example\demo_blink_led

Note: if you changed the location of the RISCV compiler, you need to modify the file "neorv32\sw\common\common.mk" on the line # 448:

...
# Compiler toolchain
    RISCV_PREFIX =  **<path where you installed your compiler under linux file system>/bin/riscv32-unknown-elf-**
...

3. Cross-Compile

Run the command make all

$ make all
Memory utilization:
text    data     bss     dec     hex filename
1012       0       0    1012     3f4 main.elf
Executable (neorv32_exe.bin) size in bytes:
1024
Installing application image to ../../../rtl/core/neorv32_application_image.vhd

List the generated files and you will see

$ ls -l
-rw-r--r-- 1 adrizcorp adrizcorp 18160 Feb 24 01:54 main.asm
-rw-r--r-- 1 adrizcorp adrizcorp  1012 Feb 24 01:54 main.bin
-rw-r--r-- 1 adrizcorp adrizcorp  4314 Feb 23 15:08 main.c
-rw-r--r-- 1 adrizcorp adrizcorp  7696 Feb 24 01:54 main.c.o
-rwxr-xr-x 1 adrizcorp adrizcorp 42856 Feb 24 01:54 main.elf
-rw-r--r-- 1 adrizcorp adrizcorp   141 Feb 23 15:08 makefile
-rw-r--r-- 1 adrizcorp adrizcorp  3704 Feb 24 01:54 neorv32_application_image.vhd
-rw-r--r-- 1 adrizcorp adrizcorp  1024 Feb 24 01:54 neorv32_exe.bin
-rw-r--r-- 1 adrizcorp adrizcorp  1012 Feb 24 01:54 neorv32_raw_exe.bin
-rw-r--r-- 1 adrizcorp adrizcorp  2277 Feb 24 01:54 neorv32_raw_exe.hex

Now you have been able to compile C code for the RISCV processor.

Enjoy!