fbstatus

Overview ¶

fbstatus is a Linux framebuffer status display for the Tailscale appliance. It draws the Tailscale logo, the tailscaled backend state, the device's tailnet IP addresses, and (when the device needs to be logged in) a QR code containing the login URL so a user can enroll the appliance into a tailnet by pointing their phone camera at the screen.

fbstatus accesses the framebuffer via the Linux UAPI in include/uapi/linux/fb.h: FBIOGET_VSCREENINFO and FBIOGET_FSCREENINFO ioctls plus an mmap of /dev/fb0. Only 32-bit truecolor framebuffers (the Raspberry Pi default) are supported.