Is it Possible to send data directly to the GPU via a custom hardware interface? Is it possible to directly bypass the CPU while transferring data to the GPU? could there be hardware which gives the GPU direct memory access to a data stream for real-time GPU processing and rendering?
On a desktop (or laptop) the GPU is connected to the PCIe bus. This gives it direct access to the physical RAM. 

If you map the buffer you want to fill and then read a file into that mapped memory. The OS will tell the disk drive to dump the file into the physical ram (the disk also has direct memory access), then when you go to use the mapped buffer the driver will tell the gpu to copy it into the vram. All the while the CPU never touched that bit of ram.