# MESA Driver sponsored by NLnet

todo http://lists.libre-soc.org/pipermail/libre-soc-dev/2020-August/000246.html

# Build Instructions (by Cole from Vivek's comments on the mailing list)

This tutorial assumes, like the rest of the info on the wiki, that you are running Debian 10.4 either natively or in a virtualized setup.

The following is available as scripts in the libre-soc dev-env-setup repo, and can be easily used by running `sudo ./install-mesa-apt-reqs && ./lsoc-mesa-dev-env-setup`.

First, we need to install the necessary apt dependencies for building `drm` and `mesa`.

In order to install a `meson` version recent enough to configure `mesa`, add buster-backports to /etc/apt/sources.list by running the following as root:

    echo "deb http://deb.debian.org/debian buster-backports main" | tee \
     -a /etc/apt/sources.list

Install `meson` (version 52.0 or later):

    apt-get update -y
    apt-get install -y -t buster-backports meson

Then install the necessary packages by running the following commands as root:

    apt-get update -y
    apt-get upgrade -y
    apt-get install -y build-essential \
        cmake \
        git \
        pkg-config \
        libatomic-ops-dev \
        libcairo2-dev \
        libcunit1-dev \
        libpciaccess-dev \
        libunwind-dev \
        llvm-8 \
        llvm-8-dev \
        python3.7 \
        python3.7-dev \
        python3-setuptools \
        libzstd-dev \
        libzstd1 \
        zlib1g

Then, still as root, run the following to get the necessary dependencies for building `drm` and `mesa`.

    apt-get build-dep -y libdrm
    apt-get build-dep -y mesa

Now we are going to build and install `drm` from source as the debian apt versions are not recent enough to build mesa. Run all of these command as a regular user, **DO NOT RUN AS ROOT** it is not necessary.

First, create our working directory `opt` in our user directory. In order to not mess with system `drm` and `mesa` libraries, also create a sub-directory `lsoc_mesa` to hold our header files and libraries. After creating the `opt` directory, cd into it to make it our active, current working directory.

    mkdir -p ~/opt/lsoc_mesa
    cd ~/opt
    
Now clone `drm` from mesa's gitlab. Change to the `drm` directory. Create a build directory and cd into it.

    git clone https://gitlab.freedesktop.org/mesa/drm.git
    cd drm
    mkdir build && cd build

In order to configure `drm` for building and installation run the following command. It is very important to specify `prefix=/home/$USER/opt/lsoc_mesa` because as mentioned above we need these files for development purposes, but we do not want to corrupt or interfere with our *system* `drm` libraries.

    meson -Dbuildtype=release -Dprefix=/home/$USER/opt/lsoc_mesa ..

After configuration has completed, run ninja to build and install the `drm` libraries.

    ninja install
 
In order for meson to be able to find the up-to-date `drm` files we have just built, we need to specify their location with the environment variable `PKG_CONFIG_PATH`.

    export PKG_CONFIG_PATH=~/opt/lsoc_mesa/lib/x86_64-linux-gnu/pkgconfig/

These following `vulkan`-specific environment variables are necessary to build our branch of mesa successfully:

    export VK_ICD_FILENAMES=/home/$USER/opt/lsoc_mesa/share/vulkan/icd.d/libresoc_icd.x86_64.json
    export VK_LOADER_DEBUG=warn
    export LIBRESOC_TRACE=1

Now change back to the base `~/opt` directory and clone the `mesa` git repo from the `mesa` gitlab instance. Change to the `mesa` directory. Create a build directory and cd into it.

    cd ~/opt
    git clone https://git.libre-soc.org/git/mesa.git
    git pull --rebase origin libresoc_dev
    git checkout -b libresoc_dev
    cd mesa
    mkdir build && cd build

In order to configure `mesa` for building and installation run the following command. Again, it is *very* important to specify `prefix=/home/$USER/opt/lsoc_mesa` because as mentioned above we need these files for development purposes, but we do not want to corrupt or interfere with our *system* `mesa` libraries.

    meson -Dbuildtype=debug -Dprefix=/home/$USER/opt/lsoc_mesa \
     -Dvulkan-drivers=libre-soc ..             

After configuration has completed, run ninja to build and install the `mesa` libraries.

    ninja install

# From here on is solely Vivek's instructions

To test the code I am sing simple tests built by

    https://github.com/GameTechDev/IntroductionToVulkan

I am also using debug build for vulkan loader if any one interested in that
please look at

    https://github.com/KhronosGroup/Vulkan-Loader/blob/master/BUILD.md

I have pushed code to the new branch
https://gitlab.freedesktop.org/vivekvpandya/mesa/-/tree/libresoc_dev
previously it was on master so it will cause me problems working on master
branch.

# Running vulkan intro tutorial

* <https://github.com/GameTechDev/IntroductionToVulkan/tree/master/Project/Tutorials/01>
* <http://lists.libre-soc.org/pipermail/libre-soc-dev/2020-August/000368.html>

# Demos with lavapipe

> It can be built with 
> meson configure -Dvulkan-drivers=swrast -Dgallium-drivers=swrast
> set VK_ICD_FILENAMES to the lvp_icd.x86_64.json file and vulkaninfo should
> show it.
> 
> I tried running demos from
> https://software.intel.com/content/www/us/en/develop/articles/api-without-
> secrets-introduction-to-vulkan-part-1.html and all 7 runs fine with lavapipe.

* <https://bugs.libre-soc.org/show_bug.cgi?id=251#c58>