# Documentation

A draft version of the specification is available at
<https://ftp.libre-soc.org/power-spec-draft.pdf>

## Codebase Structure

The SOC is partitioned into four repositories. The subrepositories are
intended as general purpose standalone projects useful outside of LibreSOC. For example,
the IEE754 FPU repository is a general purpose IEEE754 toolkit for the
construction of FSMs and arbitrary length pipelines.

| Git Repo | Online docs   | Description   | Pypi    |
|----------|---------------|---------------|--------
| [SOC](https://git.libre-soc.org/?p=soc.git;a=tree) | [Libre-SOC](https://docs.libre-soc.org/soc/) | Main OpenPOWER Hybrid CPU-GPU | TBD |
| [FPU](https://git.libre-soc.org/?p=ieee754fpu.git;a=tree) | -- | Equivalent to hardfloat-3 | [libresoc-ieee754fpu](https://pypi.org/project/libresoc-ieee754fpu) |
| [nmutil](https://git.libre-soc.org/?p=nmutil.git;a=tree) | -- | Equivalent to Chisel3.util | [libresoc-nmutil](https://pypi.org/project/libresoc-nmutil) |
| [OpenPOWER ISA](https://git.libre-soc.org/?p=nmutil.git;a=tree) | [OpenPOWER ISA](https://docs.libre-soc.org/openpower-isa/) | Simulator, ISA spec compiler, co-simulation infrastructure |  [libresoc-openpower-isa](https://pypi.org/project/libresoc-openpower-isa/)  |


Also see [[SOC Architecture|3d_gpu/architecture]]

## Installing the Codebase

Installation is much easier when using the
[install scripts](https://git.libre-soc.org/?p=dev-env-setup.git;a=blob;f=hdl-dev-repos;hb=HEAD).
A separate script also helps install
[dependencies](https://git.libre-soc.org/?p=dev-env-setup.git;a=blob;f=install-hdl-apt-reqs;hb=HEAD)
and a third can be used to set up a
[debootstrap chroot](
https://git.libre-soc.org/?p=dev-env-setup.git;a=blob;f=mk-deb-chroot;hb=HEAD).
The chroot is useful to ensure stability and repeatable builds: no
errors or issues introduced by libraries being wrong versions.
Also relevant is the [gdb gcc build](https://git.libre-soc.org/?p=dev-env-setup.git;a=blob;f=ppc64-gdb-gcc;hb=HEAD).

    pip3 install virtualenv requests
    mkdir ~/.virtualenvs && cd ~/.virtualenvs
    python3 -m venv libresoc
    source ~/.virtualenvs/libresoc/bin/activate
    
    cd ~; mkdir libresoc; cd libresoc
    git clone https://git.libre-soc.org/git/nmutil.git
    git clone https://git.libre-soc.org/git/openpower-isa.git
    git clone https://git.libre-soc.org/git/c4m-jtag.git
    git clone https://git.libre-soc.org/git/ieee754fpu.git
    git clone https://git.libre-soc.org/git/soc.git
    
    cd nmutil; make develop; cd ..
    cd openpower-isa; make develop; cd ..
    cd c4m-jtag; make develop; cd ..
    cd ieee754fpu; make develop; cd ..
    cd soc; make gitupdate; make develop; cd ..
    
    python3 soc/src/soc/decoder/power_decoder.py
    yosys -p "read_ilang decoder.il; show dec31" 

## Gtkwave Tutorial

[[docs/gtkwave_tutorial]]

## Formal proof notes

[[docs/notes_on_formal_proofs]]

## Learning nmigen

[[docs/learning_nmigen]]