./vbtracetool 
Using card 10de:0146 on 0100
Nvidia card -- using PROM/PRAMIN BIOS
Using card memory region at 0xcf000000
Attempting to locate BIOS image in PROM... BIOS signature not found
Attempting to locate BIOS image in PRAMIN... appears to be valid
ax: 0x004f, bx: 0x0003, mode: 0x0003 (3)