# Panfrost

The Panfrost driver stack includes an OpenGL ES implementation for Arm Mali GPUs based on the Midgard and Bifrost microarchitectures. It is conformant on Mali-G52, Mali-G57 and Mali-G610, but non-conformant on other GPUs.

PanVK, the Vulkan implementation in the Panfrost driver stack, is currently conformant on Mali-G610, but non-conformant on other GPUs.

The following hardware is currently supported:

Models | Architecture | OpenGL ES | OpenGL | Vulkan
--- | --- | --- | --- | ---
T600, T620, T720 | Midgard (v4) | 2.0 | 2.1 |
T760, T820, T830 T860, T880 | Midgard (v5) | 3.1 | 3.1 |
G72 | Bifrost (v6) | 3.1 | 3.1 | 1.0
G31, G51, G52, G76 | Bifrost (v7) | 3.1 | 3.1 | 1.0
G57 | Valhall (v9) | 3.1 | 3.1 |
G310, G610 | Valhall (v10) | 3.1 | 3.1 | 1.4
G720 | 5th Gen (v12) | 3.1 | 3.1 | 1.4
G725 | 5th Gen (v13) | 3.1 | 3.1 | 1.4

Other Midgard and Bifrost chips (e.g. G71) are not yet supported.

Older Mali chips based on the Utgard architecture (Mali-400, Mali-450) are supported in the Lima driver, not Panfrost. Lima is also available in Mesa.

Other graphics APIs (OpenCL) are not supported at this time.

## Building

Panfrost’s OpenGL support is a Gallium driver. Since Mali GPUs are 3D-only and do not include a display controller, Mesa uses kmsro to support display controllers paired with Mali GPUs. If your board with a Panfrost supported GPU has a display controller with mainline Linux support not supported by kmsro, it’s easy to add support, see the commit `cff7de4bb597e9` as an example.

Build like `meson . build/ -Dvulkan-drivers=panfrost -Dgallium-drivers=panfrost` for a build directory `build`.

LLVM is required by Panfrost’s compilers at build time.

In case of cross compilation without LLVM, you can build and install the required tools on the host (with LLVM installed) with `meson . build-host/ -Dtools=panfrost -Dmesa-clc=enabled -Dinstall-mesa-clc=true -Dprecomp-compiler=enabled -Dinstall-precomp-compiler=true` and then use `-Dmesa-clc=system -Dprecomp-compiler=system` on the cross compile side.

For general information on building Mesa, read the install documentation.

## Chat

Panfrost developers and users hang out on IRC at `#panfrost` on OFTC. Note that registering and authenticating with `NickServ` is required to prevent spam. Join the chat.

## Technical details

You can read more technical details about Panfrost here:

- Benchmarking Panfrost
  - Make sure the device is actively cooled (to eliminate thermal throttling)
  - Fix the GPU frequency
  - Fix the CPU frequency
  - Pin the benchmark program to a particular core
- drm-shim
- Instancing
- Compressed texture support
- U-interleaved tiling