TBM 850 pilot reported the avionics system began to experience multiple failures immediately after takeoff. The pilot rebooted the avionics system and normal navigation and flight guidance was restored.

Narrative

I departed ZZZ Airport IFR and was flying the published Standard Instrument Departure. Immediately after takeoff; following gear and flap retraction; the Garmin G1000 NXi avionics system began to experience multiple failures.The initial failures included loss of GPS 1 and GPS 2; followed by loss of autopilot functionality and degradation of both Primary Flight Displays (PFDs) and the Multi-Function Display (MFD). As a result; I lost reliable navigation and flight guidance information realized I was off course (autopilot was engaged at 1000 feet; my SOP) and I was unable to maintain heading with normal system support.I advised ATC that I was experiencing multiple avionics issues and was unable to reliably hold heading. While continuing the climb; I focused on maintaining aircraft control; terrain clearance; and traffic separation. During this time; ATC asked several times if everything was OK?." Due to my high workload and prioritization of aircraft control; I responded with one word "standby."Under a high-workload and high-stress environment; and as a last resort; I initiated a total reboot of the avionics system; which is indicative of how extreme the failures and situation was as I have never had to do that in flight. When the displays and systems came back online; normal navigation and flight guidance functionality was restored.In hindsight; an earlier request to ATC from me for a block altitude and assigned heading; would have been beneficial for ATC and me; to reduce my workload. However; during the event my primary focus was three-fold: maintaining aircraft control; terrain clearance; and traffic separation while managing the system failures."