Few days ago stefanct, gave me a bunch of datasheets for GigaDevice chips, so I could get me way into flashrom.
Here is 2 pathces. One with GigaDevice chips support and one with a fix to *PROBABLE* pastebug in AMIC A25LQ64 chip definition, which I found earlier.
I never used mailing lists and not sure about mime64 attachments, so archive with datasheets can be found here: https://www.dropbox.com/s/sk5mecwj7e4z4t3/GIGADEVICE_GD25LQ.tar.bz2?dl=0