Nvidia Tegra

From postmarketOS

SoCs

Nvidia Tegra 2
NVIDIA T20 chip
NVIDIA T20 chip
Manufacturer Nvidia
Name Tegra 2
Architecture armv7
CPU 2x 1.0/1.2 GHz ARM Cortex-A9
GPU Nvidia ULP Geforce
Year 2010
Process 40nm
Mainline yes
Community Page https://github.com/grate-driver
Components
CPU
Works
UART
Works
Storage
Works
USB
Works
Display
Works
GPU
Partial
Pinctrl
Works
I²C
Works
SPI
Works
Audio
Works
Video
Partial
Thermal
Works
Camera
Broken
Suspend
Works
Nvidia Tegra 3
NVIDIA T30 chip
NVIDIA T30 chip
Manufacturer Nvidia
Name Tegra 3
Architecture armv7
CPU 4x 1.2/1.4/1.6 GHz ARM Cortex-A9
GPU Nvidia ULP Geforce
Year 2011
Process 40nm
Mainline yes
Community Page https://github.com/grate-driver
Components
CPU
Works
UART
Works
Storage
Works
USB
Works
Display
Works
GPU
Partial
Pinctrl
Works
I²C
Works
SPI
Works
Audio
Works
Video
Partial
Thermal
Works
Camera
Broken
Suspend
Works
Nvidia Tegra 4
NVIDIA T114 chip
NVIDIA T114 chip
Manufacturer Nvidia
Name Tegra 4
Architecture armv7
CPU 4x 1.8-1.9 GHz Cortex-A15
GPU Nvidia ULP Geforce 72 cores
Year 2013
Process 28nm
Mainline yes
Community Page https://github.com/grate-driver
Components
CPU
Partial
UART
Works
Storage
Works
USB
Partial
Display
Works
GPU
Partial
Pinctrl
Works
I²C
Works
SPI
Partial
Audio
Works
Video
Partial
Thermal
Works
Camera
Broken
Suspend
Works

Tegra 2

Devices with a Tegra 2 Chipset

Device Mainline
Acer Iconia Tab A200 P
Acer Iconia Tab A500 Y
Asus Eee Pad Transformer Y
Lenovo ThinkPad Tablet
Motorola Droid X2
Nvidia Tegra ARMv7 Y
Samsung Captivate Glide P
Samsung Galaxy Tab 10.1 P
Sony Tablet S

CPU

Tegra 2 uses two A9 cores without NEON instructions.

Tegra 3

Devices with a Nvidia Tegra 3 Chipset

Device Mainline
Asus Eee Pad Transformer Prime Y
Asus Transformer Infinity Y
Asus Transformer Pad Y
Asus Transformer Pad 3G Y
Asus VivoTab RT Y
Google (ASUS) Nexus 7 (2012) Y
Google (ASUS) Nexus 7 (2012) GSM Y
Hisense Sero 7 Pro
HTC One X
HTC One X+
LG Optimus 4X HD P
LG Optimus Vu Y
Medion Lifetab S9714
Microsoft Surface RT Y
Ouya, Inc. Ouya Y
Pegatron Chagall Y
WEXLER Tab 7t Y

Tegra 4

Devices with a Nvidia Tegra 4 Chipset

Device Mainline
Asus Transformer Pad (TF701T) Y
HP Slate 21
Microsoft Surface 2 Y
Nvidia Tegra Note 7 Y

List of missing/malfunctioning drivers

  • DSI driver and MIPI calibration (malfunctioning on TF701T)
  • HDMI driver (no evidence that it can work on T114)
  • ACTMON driver (is present but has dependency on missing driver)
  • SPI driver (fails to detect some spi devices)
  • EMC/external-memory-controller driver (missing, required by actmon)
  • HDA driver (T30 has T114 support but it fails to work)
  • XUSB and XUSB-padctl (missing, T124 may be used as reference)
  • CEC driver (present but not tested since HDMI does not work)
  • SOCTHERM driver and thermal zones (missing, T124 may be used as reference)
  • DFLL driver (missing, T124 may be used as reference)
  • cortex-a15-pmu (check if it is used by t114)
  • powergates and power-domains (check if it is needed by t114)

GPU

Tegra 2/3/4 use grate driver.

Tegra K1 and newer use nouveau.

However, all Tegra SoCs share drm driver.

Tegra 2/3/4

Components (source)

  • Mesa-3D (minimal implementation, not complete enough (GL 1.4) to run XWayland (requires GL 2.1 or GLES2)
  • xf86-video-tegra (2D acceleration for X11, EXA)
  • libvdpau-tegra

Usability

Wayland:

  • Phosh works, but UI is accelerated trough llvmpipe (software rendering), thus is slow.
  • Plasma mobile not tested (please update)

X11:

  • Xfce4 and Mate desktop will run on 2D acceleration.
  • Hildon requires an OpenGL backend.
    • As of cogl 1.22.2 the clutter/cogl backend requires stencil buffers (EGL_STENCIL_SIZE). This not yet implemented in the grate-driver.

Tegra K1 and newer

See https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2960

Video Decoding

Video Decoder Engine (VDE) was added to mainline kernel v4.16. The grate-driver includes hardware h264 decoding with libvdpau-tegra.

The vdpau driver does not support h264 videos encoded with:

  • weighted prediction
  • CABAC

Sample video that can be decoded with hardware acceleration: https://peach.blender.org/trailer-page/

$ mpv --hwdec=vdpau trailer_720p.mov
Using hardware decoding (vdpau).
VO: [vdpau] 1280x720 vdpau[yuv420p]

APX

Nvidia Tegra devices have APX mode which allows to flash/debrick a device even with broken bootloader. It also allows to sideload bootloader which is useful when porting a new bootloader.

Some devices have a key combination to enter this mode, some devices don't have one. We have a hook which alters two PMC registers which causes device to enter APX mode. It works on the most devices including some of those that don't have a key combination for APX.

Usage on Android devices:

$ pmbootstrap initfs hook_add apx
$ pmbootstrap flasher boot

On Chrome OS devices and other not supporting fastboot boot command you will have to flash the image with kernel after enabling apx hook.

Participate development

Develop

Mesa3D Gallium driver

https://github.com/grate-driver/mesa

  • Host1x ABI rework (required before mesa implemenetation): (G. docs)
  • migrate from TGSI to NIR
  • establishing demos that work, where can be seen regression

New Device Trees

To generate the correct RAM timings for new Tegra 3 devices from known kernel sources, you can start from the known (downstream) RAM model code, and generate valid timings using this tool by Ion Agorria: https://gitlab.com/IonAgorria/tegra-timings-generator.

The #postmarketOS-on-transformers:matrix.org chat room will also be an excellent starting point for the porting of any new Tegra 2/3/4 device, also outside strictly the ASUS Transformer series