Persists in BIOS flash most likely - that's the writeable place. Re-flashable if the invaded BIOS even tells you that it's been changed (why would it?). And the

Persists in BIOS flash most likely - that's the writeable place. Re-flashable if the invaded BIOS even tells you that it's been changed (why would it?). And then if it lets you reflash (why would it). Let you switch to the 2nd BIOS perhaps (why would it?). You might reflash by going straight to the flash memory pins but only if you could tell that you need to - or if you are paranoid enough and have the means.