On 11/27/13 18:22, Markus Armbruster wrote: > Perhaps the proper way to back partially writable flash contents isn't > splitting it into two devices, but backing a single device with a COW. > The backing file has initial contents (say BIOS image), the delta may > have additional contents (say non-volatile configuration), and picks up > whatever the device model permits to be written to the flash.
Kevin brought this up before. The problem is that this prevents you from upgrading the read-only part in O(1). (Unless of course you're willing to make the backing file raw *and* to poke directly in it when you upgrade the bios binary part. Theoretically you could do this, because the divide between the varstore and the binary part at 128KB falls at a qcow2 block boundary (supposing a 64K qcow2 block size), but in practice this is a horrible idea :)) Let's not veer off into architecting a new star destroyer. I think I have plenty ammo from your great notes thus far that I can hack up a v2 with :) Thanks Laszlo
