The previous approach of attempting to derive it didn't work.
It turns out that the ora_ptr is 16 * the current offset.
Signed-off-by: Sean Cross <sean@xobs.io>
Instead of looping through a small window, figure out the various bit
positions and offsets. Then, as we scan through, validate that we've
found the proper offsets.
This should get us to 100% reliability.
Signed-off-by: Sean Cross <sean@xobs.io>
We can now do away with the `iceunpack`/`icebram`/`icepack` dance and
simply patch files on the fly. This should simplify development,
since you only need two files (the bitstream and the replacement rom),
rather than four files (the bitstream, the replacement rom, the
random contents, and the output file).
Signed-off-by: Sean Cross <sean@xobs.io>