You manually flush the addresses of the framebuffer via a cache maintenance instruction. The internet tells me the phone has a A53 which should be ARMv8, so pr

You manually flush the addresses of the framebuffer via a cache maintenance instruction. The internet tells me the phone has a A53 which should be ARMv8, so probably a loop of DC CIVAC (Data Cache Clean and Invalidate by Virtual Address to Coherency) instructions over the framebuffer. Though the buffer might be large enough to not even fit in the cache, so it might be more efficient to just flush the entire cache.