UDL(4) - Device Drivers Manual

UDL(4) - Device Drivers Manual #

UDL(4) - Device Drivers Manual

NAME #

udl - DisplayLink DL-120/DL-160 USB display devices

SYNOPSIS #

udl* at uhub? wsdisplay* at udl?

DESCRIPTION #

The udl driver supports USB display devices based on the DisplayLink DL-120/DL-160 graphic chip.

HARDWARE #

The following devices should work:

Century Corp. Japan Plus One LCD-8000U

Century Corp. Japan Plus One LCD-4300U

DisplayLink USB to DVI

ForwardVideo EasyCAP008 USB to DVI

HP USB 2.0 Docking Station (FQ834)

HP USB Graphics Adapter (NL571)

IOGEAR USB 2.0 External DVI (GUC2020)

Koenig CMP-USBVGA10 and CMP-USBVGA11

Lenovo 45K5296 USB to DVI

Lenovo ThinkVision LT1421

Lilliput UM-70

Nanovision MiMo UM-710 and UM-740

Rextron VCUD60 USB to DVI

Samsung LD220

StarTech CONV-USB2DVI

Sunweit USB to DVI

Toshiba Video Dock

Unitek Y-2240 USB to DVI

VideoHome NBdock1920

FILES #

The device can process compressed data (Huffman pixel difference method) to reduce the USB payload. To generate the compressed data, the driver needs to load a Huffman table, which is stored in the following binary file:

/etc/firmware/udl_huffman

If the Huffman table can’t be loaded, the driver will fall back to uncompressed mode.

SEE ALSO #

intro(4), usb(4), wscons(4), wsdisplay(4)

HISTORY #

The udl driver first appeared in OpenBSD 4.6.

AUTHORS #

Marcus Glocker <mglocker@openbsd.org>

OpenBSD 7.5 - May 10, 2023