# Development Environment

> Note: This section talks about the development environment for the project. Integrating and using the Kronos Core doesn't require setting up the development environment! Head on over to the [integration section](integration.md). If you want to build the KRZ SoC, then head over [here](krz_soc.md).

## Tools
The Kronos core is entirely written in SystemVerilog. The development environment is listed below:

- HDL: SystemVerilog
- Unit Testing: [VUnit](https://vunit.github.io/), a python based unit testing framework for SystemVerilog. The project has excepts this package installed for python3
- SV Simulator: [Modelsim FPGA Starter Edition](https://www.intel.com/content/www/us/en/software/programmable/quartus-prime/model-sim.html). It's "free", and the waveform viewer is leagues ahead of gtkwave.
- Linting - [Verilator](https://www.veripool.org/wiki/verilator)
- Build System: CMake
- RISC-V GNU toolchain configured for `rv32i`

This is my go-to development setup for digital design work. Linting with verilator, unit testing with vunit and seamless HDL dependency maintenance and build with cmake.

## Environment Variables
In order for cmake to find all the dependencies and tools, certain environment variables need to be setup (in your bashrc) and in your PATH.

```
export LATTICE_LIBRARY="~/work/icelib/ice40up"          # lattice compiled lib
export RISCV_TOOLCHAIN_DIR="/opt/riscv32i"              # your riscv-gnu toolchain

PATH="$PATH:/opt/verilator-v4.026/bin"
PATH="$PATH:/opt/intelFPGA_pro/19.4/modelsim_ase/bin"   # your modelsim install
PATH="$PATH:/opt/lscc/radiant/2.0/bin/lin64"            # your radiant install
```

Also make sure that `VERILATOR_ROOT` isn't setup in your environment. It messes with verilator's own makefiles (while compiling verilated modules).


## Lattice Primitive Library
Where the Lattice lib points to the pre-compliled iCE40UP series primitive/simulation library for modelsim. To compile the library for modelsim. This is only needed by test targets and designs (platforms) that use Lattice primitives.

```    
export FOUNDRY=/opt/lscc/radiant/2.0/ispfpga                 # where radiant is installed. The script needs this temporary env var defined

cd ${FOUNDRY}/../cae_library/simulation/scripts              

tclsh cmpl_libs.tcl \
    -sim_path /opt/intelFPGA_pro/19.4/modelsim_ase/bin \    # your modelsim install
    -device ice40up \
    -target_path ~/work/icelib                              # where you want the lib to be compiled to

```


## CMake Build
CMake is an out-of-source build, and thus you need to create a build directory before setting up the build targets.
```
cd kronos
mkdir build
cd build

cmake .. -DCMAKE_BUILD_TYPE=Dev

make help               # list all available targets

make lint-kronos_core   # lint the kronos_core

make testdata-all       # compile all riscv test programs and convert them to SV memory files

make test               # run all tests in the project

```