Introduction

This plugin is used to detach the System76 Launch device to DFU mode.

To switch to bootloader mode a USB packet must be written, as specified by the System76 EC protocol.

GUID Generation

These devices use the standard USB DeviceInstanceId values, e.g.

• USB\VID_3384&PID_0001&REV_0001
• USB\VID_3384&PID_0005&REV_0001
• USB\VID_3384&PID_0006&REV_0001
• USB\VID_3384&PID_0007&REV_0001

Update Behavior

The device usually presents in runtime mode, but on detach re-enumerates with a different USB VID and PID in DFU mode. The device is then handled by the dfu plugin.

On DFU attach the device again re-enumerates back to the runtime mode.

For this reason the REPLUG_MATCH_GUID internal device flag is used so that the bootloader and runtime modes are treated as the same device.

Vendor ID Security

The vendor ID is set from the USB vendor, in this instance set to USB:0x3384

External Interface Access

This plugin requires read/write access to /dev/bus/usb.