Hi Ken,

I would guess that there is some GPIO-controlled write protection mechanism enabled on that board. Sometimes you can disable these thru BIOS settings, though it's entirely up to the vendor whether or not to expose that.

Of course, rebooting and toggling that setting in the BIOS is sort of a pain and probably unfeasible if you wish to support more than a small handful of motherboards. So it's usually preferable to toggle that setting in Flashrom. In Flashrom's board_enable.c file, you'll see several routines which do things like raise a GPIO to disable write protection. You'll probably need to do something similar for your board.

If you're reasonably familiar with the chipset you're using (SCH US15WPT), you can try to determine the write protection setting experimentally. Here is one example of how to do it: http://www.coreboot.org/pipermail/coreboot/2009-September/051987.html .

Much of the tedious info such gathering and calculating base addresses and offsets can be found from flashrom verbose output when you perform a read operation. iotools can also make your life easier when doing simple low-level operations.