I am pretty sure my customized image was written into the rom. I flashed the same image again after I saw the request of using "-v" parameter and decided to pipe the output to a file.
The adapter was shipped with MBA/PXE boot rom and I have flashed it with plop boot manager. The manager is now fully functional so I can assure you that something new has been written in the rom.

Lu

On Mar 4, 2013 7:26 PM, "Stefan Tauner" <stefan.tauner@student.tuwien.ac.at> wrote:
On Tue, 5 Mar 2013 07:40:25 +0800
Lu Xie <lxie1@andrew.cmu.edu> wrote:

> Erasing and writing flash chip... Trying erase function 0... 0x000000-0x00ffff:S
> Erase/write done.
> Verifying flash... VERIFIED.

Hi and thanks for your report!

The ":S" after the address range means that flashrom has detected that
the data on the chip was already equal to the image you provided. I
presume that you actually did write exactly that image to the chip
already previously. Can you confirm that the contents of the chip
really have changed?

--
Kind regards/Mit freundlichen Grüßen, Stefan Tauner